Inorganic or organic compounds that contain the basic structure RB(OH)2.
A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.
A field of chemistry which pertains to chemical compounds or ions that do not contain the element carbon (with the exception of carbon dioxide and compounds containing a carbonate radical, e.g., calcium carbonate).
Organic compounds which contain tin in the molecule. Used widely in industry and agriculture.
Inorganic and organic derivatives of boric acid either B(OH)3 or, preferably H3BO3.
A generic grouping for dihydric alcohols with the hydroxy groups (-OH) located on different carbon atoms. They are viscous liquids with high boiling points for their molecular weights.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.
Salts and esters of gentisic acid.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
Clavulanic acid and its salts and esters. The acid is a suicide inhibitor of bacterial beta-lactamase enzymes from Streptomyces clavuligerus. Administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase.
'Ketones' are organic compounds with a specific structure, characterized by a carbonyl group (a carbon double-bonded to an oxygen atom) and two carbon atoms, formed as byproducts when the body breaks down fats for energy due to lack of glucose, often seen in diabetes and starvation states.
A technology, in which sets of reactions for solution or solid-phase synthesis, is used to create molecular libraries for analysis of compounds on a large scale.
"Esters are organic compounds that result from the reaction between an alcohol and a carboxylic acid, playing significant roles in various biological processes and often used in pharmaceutical synthesis."
Inorganic or organic compounds that contain boron as an integral part of the molecule.
Nonsusceptibility of bacteria to the action of the beta-lactam antibiotics. Mechanisms responsible for beta-lactam resistance may be degradation of antibiotics by BETA-LACTAMASES, failure of antibiotics to penetrate, or low-affinity binding of antibiotics to targets.
Pyrazines are heterocyclic organic compounds containing a six-membered ring with two nitrogen atoms at opposite positions, often responsible for the characteristic flavors and aromas found in various foods, beverages, and some biological systems, but they do not have a direct medical definition as they are not a drug, treatment, or a significant component of human physiology or pathology.
Infections with bacteria of the family ENTEROBACTERIACEAE.
Four-membered cyclic AMIDES, best known for the PENICILLINS based on a bicyclo-thiazolidine, as well as the CEPHALOSPORINS based on a bicyclo-thiazine, and including monocyclic MONOBACTAMS. The BETA-LACTAMASES hydrolyze the beta lactam ring, accounting for BETA-LACTAM RESISTANCE of infective bacteria.
Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).
Gram-negative, non-motile, capsulated, gas-producing rods found widely in nature and associated with urinary and respiratory infections in humans.
A family of gram-negative, facultatively anaerobic, rod-shaped bacteria that do not form endospores. Its organisms are distributed worldwide with some being saprophytes and others being plant and animal parasites. Many species are of considerable economic importance due to their pathogenic effects on agriculture and livestock.
A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.
A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.
The molecular designing of drugs for specific purposes (such as DNA-binding, enzyme inhibition, anti-cancer efficacy, etc.) based on knowledge of molecular properties such as activity of functional groups, molecular geometry, and electronic structure, and also on information cataloged on analogous molecules. Drug design is generally computer-assisted molecular modeling and does not include pharmacokinetics, dosage analysis, or drug administration analysis.
A trace element with the atomic symbol B, atomic number 5, and atomic weight [10.806; 10.821]. Boron-10, an isotope of boron, is used as a neutron absorber in BORON NEUTRON CAPTURE THERAPY.
Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
Substances that reduce the growth or reproduction of BACTERIA.
Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
A nonlinear electrophoretic technique used to separate a variety of ionic compounds, ranging from small metal ions to large molecules like proteins. Unlike "linear" zone electrophoresis in which separating solute bands continually spread by diffusion or dispersion, isotachophoresis forms self-sharpening, adjacent zones of substantially pure solute whose concentrations often exceed several mgs/ml. In isotachophoresis a multianalyte sample is introduced between the leading electrolyte and the terminating electrolyte where the sample ions have lower electrophoretic mobilities than the leading ion but larger than the terminating ion. (From "Isotachophoresis" on the AES Web Site [Internet]. Madison, WI: The American Electrophoresis Society; c2000-2008 [cited 2009 Aug 20]. Available from
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Proteins found in any species of bacterium.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The rate dynamics in chemical or physical systems.
An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. It is produced by glands on the tongue and by the pancreas and initiates the digestion of dietary fats. (From Dorland, 27th ed) EC
A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
Any chemical species which acts as an electron-pair donor in a chemical bonding reaction with a LEWIS ACID.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Any chemical species which accepts an electron-pair from a LEWIS BASE in a chemical bonding reaction.

Temperature-jump studies on the interaction of benzeneboronic acid with chymotrypsinogen. (1/1529)

The interaction of chymotrypsinogen A with benzeneboronic acid (BBA), a transition state along inhibitor of serine proteases, was investigated by the temperature-jump method using pH indicators. It was found that l/tau is dependent on BBA concentration, in contrast to the case of the alpha-chymotrypsin [EC]-BBA system in which l/tau is independent of BBA concentration. By examination of the pH dependences of the kinetic parameters, the acid dissociation behavior of His 57 in chymotrypsinogen, chymotrypsinogen-trigonal BBA complex and chymotrypsinogen-tetrahedral BBA complex was analyzed. The kinetic deuterium isotope effect was also examined and found to occur principally on the acid dissociation constants. The state of the catalytic residues in the zymogen molecule is discussed based on these results.  (+info)

Proteasome inhibitors: a novel class of potent and effective antitumor agents. (2/1529)

The ubiquitin-proteasome pathway plays a critical role in the regulated degradation of proteins involved in cell cycle control and tumor growth. Dysregulating the degradation of such proteins should have profound effects on tumor growth and cause cells to undergo apoptosis. To test this hypothesis, we developed a novel series of proteasome inhibitors, exemplified by PS-341, which we describe here. As determined by the National Cancer Institute in vitro screen, PS-341 has substantial cytotoxicity against a broad range of human tumor cells, including prostate cancer cell lines. The PC-3 prostate cell line was, therefore, chosen to further examine the antitumor activity of PS-341. In vitro, PS-341 elicits proteasome inhibition, leading to an increase in the intracellular levels of specific proteins, including the cyclin-dependent kinase inhibitor, p21. Moreover, exposure of such cells to PS-341 caused them to accumulate in the G2-M phase of the cell cycle and subsequently undergo apoptosis, as indicated by nuclear condensation and poly(ADP-ribose) polymerase cleavage. Following weekly i.v. treatment of PS-341 to mice bearing the PC-3 tumor, a significant decrease (60%) in tumor burden was observed in vivo. Direct injection of PS-341 into the tumor also caused a substantial (70%) decrease in tumor volume with 40% of the drug-treated mice having no detectable tumors at the end of the study. Studies also revealed that i.v. administration of PS-341 resulted in a rapid and widespread distribution of PS-341, with highest levels identified in the liver and gastrointestinal tract and lowest levels in the skin and muscle. Modest levels were found in the prostate, whereas there was no apparent penetration of the central nervous system. An assay to follow the biological activity of the PS-341 was established and used to determine temporal drug activity as well as its ability to penetrate tissues. As such, PS-341 was shown to penetrate PC-3 tumors and inhibit intracellular proteasome activity 1.0 h after i.v. dosing. These data illustrate that PS-341 not only reaches its biological target but has a direct effect on its biochemical target, the proteasome. Importantly, the data show that inhibition of this target site by PS-341 results in reduced tumor growth in murine tumor models. Together, the results highlight that the proteasome is a novel biochemical target and that inhibitors such as PS-341 represent a unique class of antitumor agents. PS-341 is currently under clinical evaluation for advanced cancers.  (+info)

A novel apoptotic pathway in quiescent lymphocytes identified by inhibition of a post-proline cleaving aminodipeptidase: a candidate target protease, quiescent cell proline dipeptidase. (3/1529)

The vast majority of lymphocytes in vivo persist in a quiescent state. These resting lymphocytes are maintained through a cellular program that suppresses apoptosis. We show here that quiescent PBMC, but not activated PBMC or transformed lymphocytes, die in the presence of highly specific post-proline aminodipeptidase inhibitors. This form of death has the hallmarks of apoptosis, such as phosphatidylserine externalization and loss of mitochondrial transmembrane potential. However, it differs from apoptosis induced by gamma irradiation in the same cells or by Fas ligation in transformed lymphocytes in terms of caspase involvement. In addition, the aminodipeptidase inhibitor-induced cell death, but not gamma-irradiation-mediated apoptosis, can be prevented by inhibition of the proteasome complex. The target of these inhibitors is not CD26/DPPIV, but probably a novel serine protease, quiescent cell proline dipeptidase, that we have recently isolated and cloned. These studies will yield a better understanding of the requirements and the mechanisms that mediate quiescent lymphocyte homeostasis in vivo.  (+info)

The proteasome inhibitor PS-341 in cancer therapy. (4/1529)

The anticancer activity of the boronic acid dipeptide proteasome inhibitor PS-341 was examined in vitro and in vivo. PS-341 was a potent cytotoxic agent toward MCF-7 human breast carcinoma cells in culture, producing an IC90 of 0.05 microM on 24 h of exposure to the drug. In the EMT-6 tumor cell survival assay, PS-341 was equally cytotoxic administered p.o. or by i.p. injection up to a dose of 2 mg/kg. PS-341 was also toxic to the bone marrow colony-forming unit-granulocyte macrophage. PS-341 increased the tumor cell killing of radiation therapy, cyclophosphamide, and cisplatin in the EMT-6/Parent tumor, but was not able to overcome the in vivo resistance of the EMT-6/CTX and EMT-6/CDDP tumors. In the tumor growth delay assay, PS-341 administered p.o. had antitumor activity against the Lewis lung carcinoma, both primary and metastatic disease. In combination, regimens with 5-fluorouracil, cisplatin, Taxol and adriamycin, PS-341 seemed to produce primarily additive tumor growth delays against the s.c. tumor and was highly effective against disease metastatic to the lungs. The proteasome is an interesting new target for cancer therapy, and the proteasome inhibitor PS-341 warrants continued investigation in cancer therapy.  (+info)

The complexed structure and antimicrobial activity of a non-beta-lactam inhibitor of AmpC beta-lactamase. (5/1529)

Beta-lactamases are the major resistance mechanism to beta-lactam antibiotics and pose a growing threat to public health. Recently, bacteria have become resistant to beta-lactamase inhibitors, making this problem pressing. In an effort to overcome this resistance, non-beta-lactam inhibitors of beta-lactamases were investigated for complementarity to the structure of AmpC beta-lactamase from Escherichia coli. This led to the discovery of an inhibitor, benzo(b)thiophene-2-boronic acid (BZBTH2B), which inhibited AmpC with a Ki of 27 nM. This inhibitor is chemically dissimilar to beta-lactams, raising the question of what specific interactions are responsible for its activity. To answer this question, the X-ray crystallographic structure of BZBTH2B in complex with AmpC was determined to 2.25 A resolution. The structure reveals several unexpected interactions. The inhibitor appears to complement the conserved, R1-amide binding region of AmpC, despite lacking an amide group. Interactions between one of the boronic acid oxygen atoms, Tyr150, and an ordered water molecule suggest a mechanism for acid/base catalysis and a direction for hydrolytic attack in the enzyme catalyzed reaction. To investigate how a non-beta-lactam inhibitor would perform against resistant bacteria, BZBTH2B was tested in antimicrobial assays. BZBTH2B significantly potentiated the activity of a third-generation cephalosporin against AmpC-producing resistant bacteria. This inhibitor was unaffected by two common resistance mechanisms that often arise against beta-lactams in conjunction with beta-lactamases. Porin channel mutations did not decrease the efficacy of BZBTH2B against cells expressing AmpC. Also, this inhibitor did not induce expression of AmpC, a problem with many beta-lactams. The structure of the BZBTH2B/AmpC complex provides a starting point for the structure-based elaboration of this class of non-beta-lactam inhibitors.  (+info)

Characterization of peptidyl boronic acid inhibitors of mammalian 20 S and 26 S proteasomes and their inhibition of proteasomes in cultured cells. (6/1529)

Proteasomes are large multisubunit proteinases which have several distinct catalytic sites. In this study a series of di- and tri-peptidyl boronic acids have been tested on the chymotrypsin-like activity of purified mammalian 20 S and 26 S proteasomes assayed with succinyl-Leu-Leu-Val-Tyr-amidomethylcoumarin (suc-Leu-Leu-Val-Tyr-AMC) as substrate. The inhibition of 20 S proteasomes is competitive but only slowly reversible. The K(i) values for the best inhibitors were in the range 10-100 nM with suc-Leu-Leu-Val-Tyr-AMC as substrate, but the compounds tested were much less effective on other proteasome activities measured with other substrates. Free boronic acid inhibitors exhibited equivalent potency to their pinacol esters. Both benzoyl (Bz)-Phe-boroLeu and benzyloxycarbonyl (Cbz)-Leu-Leu-boroLeu pinacol ester inhibited 20 S and 26 S proteasomes with non-ideal behaviour, differences in inhibition of the two forms of proteasomes becoming apparent at high inhibitor concentrations (above 3xK(i)). Both of these compounds were also potent inhibitors of 20 S and 26 S proteasomes in cultured cells. However, gel filtration of cell extracts prepared from cells treated with radiolabelled phenacetyl-Leu-Leu-boroLeu showed that only 20 S proteasomes were strongly labelled, demonstrating differences in the characteristics of inhibition of 20 S and 26 S proteasomes. The usefulness of peptidyl boronic acid inhibitors for investigations of proteasome-mediated protein degradation was confirmed by the observation that Bz-Phe-boroLeu and Cbz-Leu-Leu-boroLeu pinacol ester inhibited NFkappaB activation with IC(50) values comparable to their K(i) values for purified proteasomes. The latter result supports the view that the chymotrypsin-like activity of proteasomes assayed with suc-Leu-Leu-Val-Tyr-AMC is a critical one for protein degradation in cells.  (+info)

Proteasome inhibition measurements: clinical application. (7/1529)

BACKGROUND: PS-341, a selective inhibitor of the proteasome, currently is under evaluation as an anticancer agent in multiple phase I clinical trials. In animal-model studies, PS-341 was rapidly removed from the vascular compartment and distributed widely, quickly approaching the limits of detection. An accurate pharmacodynamic assay has been developed as an alternative or complement to pharmacokinetic measurements. METHODS: Fluorogenic kinetic assays for both the chymotryptic and tryptic activities of the proteasome have been optimized for both whole blood and blood cells. Using the ratio of these activities and the catalytic mechanism of the proteasome, we developed a novel method of calculating percentage of inhibition, using two structurally unrelated inhibitors (PS-341 and lactacystin). RESULTS: This ratio method was demonstrated to be sensitive (detection limit of 13% inhibition with 10 microgram of cell lysate), specific to the proteasome (PS-341 provides >98% inhibition), accurate (112% analyte recovery), and precise (0% +/- 5% inhibition at 0 nmol/L PS-341 and 74.5% +/- 1.7% inhibition at 200 nmol/L PS-341). Using these assays, we found that both erythrocytes and leukocytes contain proteasome at 3 micromol/L. Pharmacodynamic results for PS-341 obtained from the whole-blood ratio method were comparable to those using leukocytes determined by another method. CONCLUSIONS: The described assay provides a reliable method for studying the pharmacodynamics of proteasome inhibitors and is now in use in concurrent phase I clinical trials with PS-341.  (+info)

Lack of multicellular drug resistance observed in human ovarian and prostate carcinoma treated with the proteasome inhibitor PS-341. (8/1529)

Almost all known conventional cytotoxic anticancer drugs are less effective in killing tumor cells grown as multicellular spheroids than in killing tumor cells grown as monolayer cell cultures. This "multicellular resistance" reflects the relative intrinsic drug-resistant phenotype of most solid tumors growing in vivo and is due to factors such as limited drug penetration or reduced fractions of proliferating cells. Proteasome inhibitors such as PS-341, a dipeptide boronic acid analogue, represent an interesting new class of potential anticancer drugs, which are entering early-phase clinical trials. PS-341 has been found to have good broad-spectrum cytotoxic activity in the 60-monolayer cell line National Cancer Institute screen. However, because its relative potency has not been tested in spheroid systems, we analyzed the activity of PS-341 in a spheroid/solid tumor context using four different human ovarian carcinoma cell lines and three prostate carcinoma cell lines, respectively. We found, with one exception, that PS-341 showed equal or greater activity in spheroids than in the respective monolayer cell cultures, even in a prostate cancer spheroid model with a very low growth fraction. PS-341 induced apoptotic cell death in carcinoma cells in both culture systems. We also noted a decrease in XIAP protein, a member of the inhibitor of apoptosis (IAP) family of apoptosis inhibitors, and phosphorylation of Bcl-XL in PS-341-treated ovarian carcinoma cells. Furthermore, DNA fragmentation, a hallmark of apoptosis (in this case, induced by PS-341), was completely inhibited by the caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD). Taken together, the results indicate that unlike most other known anticancer cytotoxic drugs, PS-341 appears to be as effective in killing tumor cells grown in the form of multicell spheroids as in killing tumor cells grown in monolayer cell culture. Hence, this compound has the potential to circumvent multicellular drug resistance and, as such, may show promising activity against solid tumors with low growth fractions in vivo, which are frequently intrinsically resistant to conventional cytotoxic anticancer drugs.  (+info)

Boronic acids are organic compounds that contain a boron atom bonded to two carbon atoms and a hydroxyl group. The general formula for a boronic acid is RB(OH)2, where R represents a organic group. Boronic acids are important reagents in organic synthesis and have been used in the preparation of pharmaceuticals, agrochemicals, and materials science. They can also form stable complexes with many diols and phenols, which is the basis for their use in the detection and quantification of sugars, as well as in the design of boronic acid-based drugs that target diseases such as cancer and diabetes.

I'm sorry for the confusion, but "Palladium" is not a medical term. It is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. It's used in various applications, including jewelry, dental work, electronics, and chemical reactions. If you have any medical terms you would like me to define, please let me know!

Inorganic chemistry is a branch of chemistry that deals with the study of the properties, composition, and reactions of inorganic compounds. These compounds include metal elements and their compounds, as well as non-metals such as hydrogen, carbon monoxide, and nitrogen oxides. They also cover chemical compounds that do not contain carbon-hydrogen bonds, such as salts, oxides, and acids. Inorganic chemistry is an important field of study in areas such as materials science, geochemistry, environmental science, and industrial chemistry.

Organotin compounds are a group of chemical compounds that contain carbon, hydrogen, and tin. They have the general formula RnSnX4-n, where R represents an organic group (such as a methyl or phenyl group), X represents a halogen or other substituent, and n can range from 1 to 3. These compounds are used in a variety of applications, including as biocides, PVC stabilizers, and catalysts. However, they have also been found to have toxic effects on the immune system, endocrine system, and nervous system, and some organotin compounds have been restricted or banned for use in certain products due to these concerns.

Boric acid is not a compound that is typically produced within the body as it is an inorganic, weak acid. It is commonly used as a preservative, antiseptic, and insecticide. Boric acid can be found in various over-the-counter products such as eye wash solutions, mouthwashes, and topical creams or ointments.

The medical definition of boric acids is:

A white crystalline powder with the chemical formula B(OH)3. It is slightly soluble in water and has a wide range of uses, including as an antiseptic, insecticide, and preservative. In medicine, boric acid is used as a mild antiseptic for minor cuts, scrapes, and burns, and to treat yeast infections of the skin. It works by killing bacteria and fungi that can cause infections. Boric acid is also used in some eye wash solutions to help prevent bacterial infections.

It's important to note that boric acid can be toxic if ingested or absorbed through the skin in large amounts, so it should be used with caution and kept out of reach of children and pets.

Glycols are a type of organic compound that contain two hydroxyl (OH) groups attached to adjacent carbon atoms. They are colorless, odorless, and have a sweet taste. The most common glycols are ethylene glycol and propylene glycol. Ethylene glycol is widely used as an automotive antifreeze and in the manufacture of polyester fibers and resins, while propylene glycol is used as a food additive, in pharmaceuticals, and as a solvent in various industries. Glycols are also used as a coolant, humectant, and in the production of unsaturated polyester resins. Exposure to high levels of glycols can cause irritation to the eyes, skin, and respiratory tract, and ingestion can be harmful or fatal.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

Beta-lactamases are enzymes produced by certain bacteria that can break down and inactivate beta-lactam antibiotics, such as penicillins, cephalosporins, and carbapenems. This enzymatic activity makes the bacteria resistant to these antibiotics, limiting their effectiveness in treating infections caused by these organisms.

Beta-lactamases work by hydrolyzing the beta-lactam ring, a structural component of these antibiotics that is essential for their antimicrobial activity. By breaking down this ring, the enzyme renders the antibiotic ineffective against the bacterium, allowing it to continue growing and potentially causing harm.

There are different classes of beta-lactamases (e.g., Ambler Class A, B, C, and D), each with distinct characteristics and mechanisms for breaking down various beta-lactam antibiotics. The emergence and spread of bacteria producing these enzymes have contributed to the growing problem of antibiotic resistance, making it increasingly challenging to treat infections caused by these organisms.

To overcome this issue, researchers have developed beta-lactamase inhibitors, which are drugs that can bind to and inhibit the activity of these enzymes, thus restoring the effectiveness of certain beta-lactam antibiotics. Examples of such combinations include amoxicillin/clavulanate (Augmentin) and piperacillin/tazobactam (Zosyn).

I'm sorry for any confusion, but "Gentisates" does not appear to be a recognized term in medical or physiological sciences. It is possible that you may have misspelled or misremembered the term. If you meant "Gentiates," then it refers to a class of enzymes (also known as beta-galactosidases) that can break down certain complex carbohydrates, such as the disaccharide melibiose into galactose and glucose. However, I would recommend double-checking the spelling or context to ensure you have the correct term, as my response is based on the assumption that "Gentiates" was the intended word.

Stereoisomerism is a type of isomerism (structural arrangement of atoms) in which molecules have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientation of their atoms in space. This occurs when the molecule contains asymmetric carbon atoms or other rigid structures that prevent free rotation, leading to distinct spatial arrangements of groups of atoms around a central point. Stereoisomers can have different chemical and physical properties, such as optical activity, boiling points, and reactivities, due to differences in their shape and the way they interact with other molecules.

There are two main types of stereoisomerism: enantiomers (mirror-image isomers) and diastereomers (non-mirror-image isomers). Enantiomers are pairs of stereoisomers that are mirror images of each other, but cannot be superimposed on one another. Diastereomers, on the other hand, are non-mirror-image stereoisomers that have different physical and chemical properties.

Stereoisomerism is an important concept in chemistry and biology, as it can affect the biological activity of molecules, such as drugs and natural products. For example, some enantiomers of a drug may be active, while others are inactive or even toxic. Therefore, understanding stereoisomerism is crucial for designing and synthesizing effective and safe drugs.

Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst, which remains unchanged at the end of the reaction. A catalyst lowers the activation energy required for the reaction to occur, thereby allowing the reaction to proceed more quickly and efficiently. This can be particularly important in biological systems, where enzymes act as catalysts to speed up metabolic reactions that are essential for life.

Clavulanic acid is a type of beta-lactamase inhibitor, which is a compound that is used to increase the effectiveness of certain antibiotics. It works by preventing the breakdown of beta-lactam antibiotics (such as penicillins and cephalosporins) by bacterial enzymes called beta-lactamases. This allows the antibiotic to remain active against the bacteria for a longer period of time, increasing its ability to kill the bacteria and treat the infection.

Clavulanic acid is often combined with amoxicillin in a medication called Augmentin, which is used to treat a variety of bacterial infections, including respiratory tract infections, urinary tract infections, and skin and soft tissue infections. It may also be used in other combinations with other beta-lactam antibiotics.

Like all medications, clavulanic acid can have side effects, including gastrointestinal symptoms such as diarrhea, nausea, and vomiting. It may also cause allergic reactions in some people, particularly those who are allergic to penicillin or other beta-lactam antibiotics. It is important to follow the instructions of a healthcare provider when taking clavulanic acid or any medication.

Ketones are organic compounds that contain a carbon atom bound to two oxygen atoms and a central carbon atom bonded to two additional carbon groups through single bonds. In the context of human physiology, ketones are primarily produced as byproducts when the body breaks down fat for energy in a process called ketosis.

Specifically, under conditions of low carbohydrate availability or prolonged fasting, the liver converts fatty acids into ketone bodies, which can then be used as an alternative fuel source for the brain and other organs. The three main types of ketones produced in the human body are acetoacetate, beta-hydroxybutyrate, and acetone.

Elevated levels of ketones in the blood, known as ketonemia, can occur in various medical conditions such as diabetes, starvation, alcoholism, and high-fat/low-carbohydrate diets. While moderate levels of ketosis are generally considered safe, severe ketosis can lead to a life-threatening condition called diabetic ketoacidosis (DKA) in people with diabetes.

Combinatorial chemistry techniques are a group of methods used in the field of chemistry to synthesize and optimize large libraries of chemical compounds in a rapid and efficient manner. These techniques involve the systematic combination of different building blocks, or reagents, in various arrangements to generate a diverse array of molecules. This approach allows chemists to quickly explore a wide chemical space and identify potential lead compounds for drug discovery, materials science, and other applications.

There are several common combinatorial chemistry techniques, including:

1. **Split-Pool Synthesis:** In this method, a large collection of starting materials is divided into smaller groups, and each group undergoes a series of chemical reactions with different reagents. The resulting products from each group are then pooled together and redistributed for additional rounds of reactions. This process creates a vast number of unique compounds through the iterative combination of building blocks.
2. **Parallel Synthesis:** In parallel synthesis, multiple reactions are carried out simultaneously in separate reaction vessels. Each vessel contains a distinct set of starting materials and reagents, allowing for the efficient generation of a series of related compounds. This method is particularly useful when exploring structure-activity relationships (SAR) or optimizing lead compounds.
3. **Encoded Libraries:** To facilitate the rapid identification of active compounds within large libraries, encoded library techniques incorporate unique tags or barcodes into each molecule. These tags allow for the simultaneous synthesis and screening of compounds, as the identity of an active compound can be determined by decoding its corresponding tag.
4. **DNA-Encoded Libraries (DELs):** DELs are a specific type of encoded library that uses DNA molecules to encode and track chemical compounds. In this approach, each unique compound is linked to a distinct DNA sequence, enabling the rapid identification of active compounds through DNA sequencing techniques.
5. **Solid-Phase Synthesis:** This technique involves the attachment of starting materials to a solid support, such as beads or resins, allowing for the stepwise addition of reagents and building blocks. The solid support facilitates easy separation, purification, and screening of compounds, making it an ideal method for combinatorial chemistry applications.

Combinatorial chemistry techniques have revolutionized drug discovery and development by enabling the rapid synthesis, screening, and optimization of large libraries of chemical compounds. These methods continue to play a crucial role in modern medicinal chemistry and materials science research.

Esters are organic compounds that are formed by the reaction between an alcohol and a carboxylic acid. They are widely found in nature and are used in various industries, including the production of perfumes, flavors, and pharmaceuticals. In the context of medical definitions, esters may be mentioned in relation to their use as excipients in medications or in discussions of organic chemistry and biochemistry. Esters can also be found in various natural substances such as fats and oils, which are triesters of glycerol and fatty acids.

Boron compounds refer to chemical substances that contain the element boron (symbol: B) combined with one or more other elements. Boron is a naturally occurring, non-metallic element found in various minerals and ores. It is relatively rare, making up only about 0.001% of the Earth's crust by weight.

Boron compounds can take many forms, including salts, acids, and complex molecules. Some common boron compounds include:

* Boric acid (H3BO3) - a weak acid used as an antiseptic, preservative, and insecticide
* Sodium borate (Na2B4O7·10H2O) - also known as borax, a mineral used in detergents, cosmetics, and enamel glazes
* Boron carbide (B4C) - an extremely hard material used in abrasives, ceramics, and nuclear reactors
* Boron nitride (BN) - a compound with properties similar to graphite, used as a lubricant and heat shield

Boron compounds have a variety of uses in medicine, including as antiseptics, anti-inflammatory agents, and drugs for the treatment of cancer. For example, boron neutron capture therapy (BNCT) is an experimental form of radiation therapy that uses boron-containing compounds to selectively target and destroy cancer cells.

It's important to note that some boron compounds can be toxic or harmful if ingested, inhaled, or otherwise exposed to the body in large quantities. Therefore, they should be handled with care and used only under the guidance of a trained medical professional.

Beta-lactam resistance is a type of antibiotic resistance in which bacteria have developed the ability to inactivate or circumvent the action of beta-lactam antibiotics. Beta-lactams are a class of antibiotics that include penicillins, cephalosporins, carbapenems, and monobactams. They work by binding to and inhibiting the activity of enzymes called penicillin-binding proteins (PBPs), which are essential for bacterial cell wall synthesis.

Bacteria can develop beta-lactam resistance through several mechanisms:

1. Production of beta-lactamases: These are enzymes that bacteria produce to break down and inactivate beta-lactam antibiotics. Some bacteria have acquired genes that encode for beta-lactamases that can hydrolyze and destroy the beta-lactam ring, rendering the antibiotic ineffective.
2. Alteration of PBPs: Bacteria can also develop mutations in their PBPs that make them less susceptible to beta-lactams. These alterations can reduce the affinity of PBPs for beta-lactams or change their conformation, preventing the antibiotic from binding effectively.
3. Efflux pumps: Bacteria can also develop efflux pumps that actively pump beta-lactam antibiotics out of the cell, reducing their intracellular concentration and limiting their effectiveness.
4. Biofilm formation: Some bacteria can form biofilms, which are communities of microorganisms that adhere to surfaces and are encased in a protective matrix. Biofilms can make bacteria more resistant to beta-lactams by preventing the antibiotics from reaching their targets.

Beta-lactam resistance is a significant public health concern because it limits the effectiveness of these important antibiotics. The overuse and misuse of beta-lactams have contributed to the emergence and spread of resistant bacteria, making it essential to use these antibiotics judiciously and develop new strategies to combat bacterial resistance.

I'm sorry for any confusion, but "pyrazines" is not a term commonly used in medical definitions. Pyrazines are actually a class of organic compounds that contain a ring made up of two nitrogen atoms and three carbon atoms. They are found in various foods and contribute to their flavors. If you have any questions about organic chemistry or food science, I'd be happy to try to help!

Enterobacteriaceae are a large family of gram-negative bacteria that are commonly found in the human gut and surrounding environment. Infections caused by Enterobacteriaceae can occur when these bacteria enter parts of the body where they are not normally present, such as the bloodstream, urinary tract, or abdominal cavity.

Enterobacteriaceae infections can cause a range of symptoms depending on the site of infection. For example:

* Urinary tract infections (UTIs) caused by Enterobacteriaceae may cause symptoms such as frequent urination, pain or burning during urination, and lower abdominal pain.
* Bloodstream infections (bacteremia) caused by Enterobacteriaceae can cause fever, chills, and sepsis, a potentially life-threatening condition characterized by a whole-body inflammatory response to infection.
* Pneumonia caused by Enterobacteriaceae may cause cough, chest pain, and difficulty breathing.
* Intra-abdominal infections (such as appendicitis or diverticulitis) caused by Enterobacteriaceae can cause abdominal pain, fever, and changes in bowel habits.

Enterobacteriaceae infections are typically treated with antibiotics, but the increasing prevalence of antibiotic-resistant strains of these bacteria has made treatment more challenging in recent years. Preventing the spread of Enterobacteriaceae in healthcare settings and promoting good hygiene practices can help reduce the risk of infection.

Beta-lactams are a class of antibiotics that include penicillins, cephalosporins, carbapenems, and monobactams. They contain a beta-lactam ring in their chemical structure, which is responsible for their antibacterial activity. The beta-lactam ring inhibits the bacterial enzymes necessary for cell wall synthesis, leading to bacterial death. Beta-lactams are commonly used to treat a wide range of bacterial infections, including respiratory tract infections, skin and soft tissue infections, urinary tract infections, and bone and joint infections. However, some bacteria have developed resistance to beta-lactams through the production of beta-lactamases, enzymes that can break down the beta-lactam ring and render the antibiotic ineffective. To overcome this resistance, beta-lactam antibiotics are often combined with beta-lactamase inhibitors, which protect the beta-lactam ring from degradation.

In chemistry, an alcohol is a broad term that refers to any organic compound characterized by the presence of a hydroxyl (-OH) functional group attached to a carbon atom. This means that alcohols are essentially hydrocarbons with a hydroxyl group. The simplest alcohol is methanol (CH3OH), and ethanol (C2H5OH), also known as ethyl alcohol, is the type of alcohol found in alcoholic beverages.

In the context of medical definitions, alcohol primarily refers to ethanol, which has significant effects on the human body when consumed. Ethanol can act as a central nervous system depressant, leading to various physiological and psychological changes depending on the dose and frequency of consumption. Excessive or prolonged use of ethanol can result in various health issues, including addiction, liver disease, neurological damage, and increased risk of injuries due to impaired judgment and motor skills.

It is important to note that there are other types of alcohols (e.g., methanol, isopropyl alcohol) with different chemical structures and properties, but they are not typically consumed by humans and can be toxic or even lethal in high concentrations.

Protease inhibitors are a class of antiviral drugs that are used to treat infections caused by retroviruses, such as the human immunodeficiency virus (HIV), which is responsible for causing AIDS. These drugs work by blocking the activity of protease enzymes, which are necessary for the replication and multiplication of the virus within infected cells.

Protease enzymes play a crucial role in the life cycle of retroviruses by cleaving viral polyproteins into functional units that are required for the assembly of new viral particles. By inhibiting the activity of these enzymes, protease inhibitors prevent the virus from replicating and spreading to other cells, thereby slowing down the progression of the infection.

Protease inhibitors are often used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART) for the treatment of HIV/AIDS. Common examples of protease inhibitors include saquinavir, ritonavir, indinavir, and atazanavir. While these drugs have been successful in improving the outcomes of people living with HIV/AIDS, they can also cause side effects such as nausea, diarrhea, headaches, and lipodystrophy (changes in body fat distribution).

"Klebsiella pneumoniae" is a medical term that refers to a type of bacteria belonging to the family Enterobacteriaceae. It's a gram-negative, encapsulated, non-motile, rod-shaped bacterium that can be found in various environments, including soil, water, and the gastrointestinal tracts of humans and animals.

"Klebsiella pneumoniae" is an opportunistic pathogen that can cause a range of infections, particularly in individuals with weakened immune systems or underlying medical conditions. It's a common cause of healthcare-associated infections, such as pneumonia, urinary tract infections, bloodstream infections, and wound infections.

The bacterium is known for its ability to produce a polysaccharide capsule that makes it resistant to phagocytosis by white blood cells, allowing it to evade the host's immune system. Additionally, "Klebsiella pneumoniae" has developed resistance to many antibiotics, making infections caused by this bacterium difficult to treat and a growing public health concern.

Enterobacteriaceae is a family of gram-negative, rod-shaped bacteria that are commonly found in the intestines of humans and animals. Many species within this family are capable of causing various types of infections, particularly in individuals with weakened immune systems. Some common examples of Enterobacteriaceae include Escherichia coli (E. coli), Klebsiella pneumoniae, Proteus mirabilis, and Salmonella enterica.

These bacteria are typically characterized by their ability to ferment various sugars and produce acid and gas as byproducts. They can also be distinguished by their biochemical reactions, such as their ability to produce certain enzymes or resist specific antibiotics. Infections caused by Enterobacteriaceae can range from mild to severe, depending on the species involved and the overall health of the infected individual.

Some infections caused by Enterobacteriaceae include urinary tract infections, pneumonia, bloodstream infections, and foodborne illnesses. Proper hygiene, such as handwashing and safe food handling practices, can help prevent the spread of these bacteria and reduce the risk of infection.

Copper is a chemical element with the symbol Cu (from Latin: *cuprum*) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. Copper is found as a free element in nature, and it is also a constituent of many minerals such as chalcopyrite and bornite.

In the human body, copper is an essential trace element that plays a role in various physiological processes, including iron metabolism, energy production, antioxidant defense, and connective tissue synthesis. Copper is found in a variety of foods, such as shellfish, nuts, seeds, whole grains, and organ meats. The recommended daily intake of copper for adults is 900 micrograms (mcg) per day.

Copper deficiency can lead to anemia, neutropenia, impaired immune function, and abnormal bone development. Copper toxicity, on the other hand, can cause nausea, vomiting, abdominal pain, diarrhea, and in severe cases, liver damage and neurological symptoms. Therefore, it is important to maintain a balanced copper intake through diet and supplements if necessary.

Amines are organic compounds that contain a basic nitrogen atom with a lone pair of electrons. They are derived from ammonia (NH3) by replacing one or more hydrogen atoms with alkyl or aryl groups. The nomenclature of amines follows the substitutive type, where the parent compound is named as an aliphatic or aromatic hydrocarbon, and the functional group "amine" is designated as a suffix or prefix.

Amines are classified into three types based on the number of carbon atoms attached to the nitrogen atom:

1. Primary (1°) amines: One alkyl or aryl group is attached to the nitrogen atom.
2. Secondary (2°) amines: Two alkyl or aryl groups are attached to the nitrogen atom.
3. Tertiary (3°) amines: Three alkyl or aryl groups are attached to the nitrogen atom.

Quaternary ammonium salts have four organic groups attached to the nitrogen atom and a positive charge, with anions balancing the charge.

Amines have a wide range of applications in the chemical industry, including pharmaceuticals, dyes, polymers, and solvents. They also play a significant role in biological systems as neurotransmitters, hormones, and cell membrane components.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

Chymotrypsin is a proteolytic enzyme, specifically a serine protease, that is produced in the pancreas and secreted into the small intestine as an inactive precursor called chymotrypsinogen. Once activated, chymotrypsin helps to digest proteins in food by breaking down specific peptide bonds in protein molecules. Its activity is based on the recognition of large hydrophobic side chains in amino acids like phenylalanine, tryptophan, and tyrosine. Chymotrypsin plays a crucial role in maintaining normal digestion and absorption processes in the human body.

"Drug design" is the process of creating and developing a new medication or therapeutic agent to treat or prevent a specific disease or condition. It involves identifying potential targets within the body, such as proteins or enzymes that are involved in the disease process, and then designing small molecules or biologics that can interact with these targets to produce a desired effect.

The drug design process typically involves several stages, including:

1. Target identification: Researchers identify a specific molecular target that is involved in the disease process.
2. Lead identification: Using computational methods and high-throughput screening techniques, researchers identify small molecules or biologics that can interact with the target.
3. Lead optimization: Researchers modify the chemical structure of the lead compound to improve its ability to interact with the target, as well as its safety and pharmacokinetic properties.
4. Preclinical testing: The optimized lead compound is tested in vitro (in a test tube or petri dish) and in vivo (in animals) to evaluate its safety and efficacy.
5. Clinical trials: If the preclinical testing is successful, the drug moves on to clinical trials in humans to further evaluate its safety and efficacy.

The ultimate goal of drug design is to create a new medication that is safe, effective, and can be used to improve the lives of patients with a specific disease or condition.

Boron is a chemical element with the symbol B and atomic number 5. It is a metalloid that is light-colored, hard, and highly resistant to corrosion. In its crystalline form, boron is nearly as hard as diamond.

In medicine, boron compounds have been studied for their potential therapeutic uses, particularly in the treatment of cancer. For example, boron neutron capture therapy (BNCT) is a type of radiation therapy that involves the use of boron-containing compounds to selectively deliver radiation to cancer cells.

Boron is also an essential micronutrient for plants and some animals, including humans. However, excessive exposure to boron can be toxic to humans and other organisms. Therefore, it is important to maintain appropriate levels of boron in the body and environment.

Microbial sensitivity tests, also known as antibiotic susceptibility tests (ASTs) or bacterial susceptibility tests, are laboratory procedures used to determine the effectiveness of various antimicrobial agents against specific microorganisms isolated from a patient's infection. These tests help healthcare providers identify which antibiotics will be most effective in treating an infection and which ones should be avoided due to resistance. The results of these tests can guide appropriate antibiotic therapy, minimize the potential for antibiotic resistance, improve clinical outcomes, and reduce unnecessary side effects or toxicity from ineffective antimicrobials.

There are several methods for performing microbial sensitivity tests, including:

1. Disk diffusion method (Kirby-Bauer test): A standardized paper disk containing a predetermined amount of an antibiotic is placed on an agar plate that has been inoculated with the isolated microorganism. After incubation, the zone of inhibition around the disk is measured to determine the susceptibility or resistance of the organism to that particular antibiotic.
2. Broth dilution method: A series of tubes or wells containing decreasing concentrations of an antimicrobial agent are inoculated with a standardized microbial suspension. After incubation, the minimum inhibitory concentration (MIC) is determined by observing the lowest concentration of the antibiotic that prevents visible growth of the organism.
3. Automated systems: These use sophisticated technology to perform both disk diffusion and broth dilution methods automatically, providing rapid and accurate results for a wide range of microorganisms and antimicrobial agents.

The interpretation of microbial sensitivity test results should be done cautiously, considering factors such as the site of infection, pharmacokinetics and pharmacodynamics of the antibiotic, potential toxicity, and local resistance patterns. Regular monitoring of susceptibility patterns and ongoing antimicrobial stewardship programs are essential to ensure optimal use of these tests and to minimize the development of antibiotic resistance.

Anti-bacterial agents, also known as antibiotics, are a type of medication used to treat infections caused by bacteria. These agents work by either killing the bacteria or inhibiting their growth and reproduction. There are several different classes of anti-bacterial agents, including penicillins, cephalosporins, fluoroquinolones, macrolides, and tetracyclines, among others. Each class of antibiotic has a specific mechanism of action and is used to treat certain types of bacterial infections. It's important to note that anti-bacterial agents are not effective against viral infections, such as the common cold or flu. Misuse and overuse of antibiotics can lead to antibiotic resistance, which is a significant global health concern.

Serine endopeptidases are a type of enzymes that cleave peptide bonds within proteins (endopeptidases) and utilize serine as the nucleophilic amino acid in their active site for catalysis. These enzymes play crucial roles in various biological processes, including digestion, blood coagulation, and programmed cell death (apoptosis). Examples of serine endopeptidases include trypsin, chymotrypsin, thrombin, and elastase.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

Isotachophoresis is a technique used in electrophoresis, which is a method for separating charged particles based on their different migration rates in an electric field. In isotachophoresis, a discontinuous system of buffer solutions with different pH values and ionic mobilities is established in a capillary or other separation medium. The sample to be analyzed is introduced into the system, and an electric field is applied.

The ions in the sample migrate towards the electrodes based on their charges and the electric field. As they migrate, they form zones of constant velocity, called isotachopheres, where the velocity of each ion is equal to that of the leading and terminating ions in the zone. The leading ion has a higher mobility than the following ions, while the terminating ion has a lower mobility.

The isotachopheres are formed in order of decreasing mobility, with the leading ion of each zone having a higher mobility than the terminating ion of the preceding zone. This results in a sharp and well-defined separation of the ions based on their electrophoretic mobilities, which is related to their charges and sizes.

Isotachophoresis has several advantages over other electrophoretic techniques, including high resolution, rapid analysis times, and the ability to analyze samples with a wide range of pH values and ionic strengths. It is commonly used in biochemistry and clinical chemistry for the separation and quantitation of ions, peptides, proteins, and other charged molecules.

X-ray crystallography is a technique used in structural biology to determine the three-dimensional arrangement of atoms in a crystal lattice. In this method, a beam of X-rays is directed at a crystal and diffracts, or spreads out, into a pattern of spots called reflections. The intensity and angle of each reflection are measured and used to create an electron density map, which reveals the position and type of atoms in the crystal. This information can be used to determine the molecular structure of a compound, including its shape, size, and chemical bonds. X-ray crystallography is a powerful tool for understanding the structure and function of biological macromolecules such as proteins and nucleic acids.

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

Magnetic Resonance Spectroscopy (MRS) is a non-invasive diagnostic technique that provides information about the biochemical composition of tissues, including their metabolic state. It is often used in conjunction with Magnetic Resonance Imaging (MRI) to analyze various metabolites within body tissues, such as the brain, heart, liver, and muscles.

During MRS, a strong magnetic field, radio waves, and a computer are used to produce detailed images and data about the concentration of specific metabolites in the targeted tissue or organ. This technique can help detect abnormalities related to energy metabolism, neurotransmitter levels, pH balance, and other biochemical processes, which can be useful for diagnosing and monitoring various medical conditions, including cancer, neurological disorders, and metabolic diseases.

There are different types of MRS, such as Proton (^1^H) MRS, Phosphorus-31 (^31^P) MRS, and Carbon-13 (^13^C) MRS, each focusing on specific elements or metabolites within the body. The choice of MRS technique depends on the clinical question being addressed and the type of information needed for diagnosis or monitoring purposes.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Lipase is an enzyme that is produced by the pancreas and found in the digestive system of most organisms. Its primary function is to catalyze the hydrolysis of fats (triglycerides) into smaller molecules, such as fatty acids and glycerol, which can then be absorbed by the intestines and utilized for energy or stored for later use.

In medical terms, lipase levels in the blood are often measured to diagnose or monitor conditions that affect the pancreas, such as pancreatitis (inflammation of the pancreas), pancreatic cancer, or cystic fibrosis. Elevated lipase levels may indicate damage to the pancreas and its ability to produce digestive enzymes.

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) is a type of mass spectrometry that is used to analyze large biomolecules such as proteins and peptides. In this technique, the sample is mixed with a matrix compound, which absorbs laser energy and helps to vaporize and ionize the analyte molecules.

The matrix-analyte mixture is then placed on a target plate and hit with a laser beam, causing the matrix and analyte molecules to desorb from the plate and become ionized. The ions are then accelerated through an electric field and into a mass analyzer, which separates them based on their mass-to-charge ratio.

The separated ions are then detected and recorded as a mass spectrum, which can be used to identify and quantify the analyte molecules present in the sample. MALDI-MS is particularly useful for the analysis of complex biological samples, such as tissue extracts or biological fluids, because it allows for the detection and identification of individual components within those mixtures.

A Lewis base, also known as a nucleophile, is a species that can donate a pair of electrons to form a covalent bond. It is named after Gilbert N. Lewis, who introduced the concept of electron pair bonds in 1923. In the context of chemical reactions, a Lewis base is an electron-rich molecule or ion that can attack an electron-deficient species, such as a Lewis acid, to form a new bond. The Lewis base donates a pair of electrons to the Lewis acid, which accepts them, forming a coordination complex.

The definition of a Lewis base can be formalized by the following reaction:

:B + :Lewis Acid \---> :B-Lewis Acid

Where B is the Lewis base and Lewis Acid is the electron-deficient species that accepts the electrons donated by the Lewis base. The double colon (::) represents an empty orbital that can accept a pair of electrons to form a new bond.

Examples of Lewis bases include hydroxide ion (OH-), alkoxides (RO-), amines (:NR3), and carbanions (:CR3). These species all have at least one pair of unshared electrons that can be donated to form a new bond with a Lewis acid.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

Organic chemistry is a branch of chemistry that deals with the study of carbon-containing compounds, their synthesis, reactions, properties, and structures. These compounds can include both naturally occurring substances (such as sugars, proteins, and nucleic acids) and synthetic materials (such as plastics, dyes, and pharmaceuticals). A key characteristic of organic molecules is the presence of covalent bonds between carbon atoms or between carbon and other elements like hydrogen, oxygen, nitrogen, sulfur, and halogens. The field of organic chemistry has played a crucial role in advancing our understanding of chemical processes and has led to numerous technological and medical innovations.

I'm sorry for any confusion, but "Lewis acids" is actually a term from the field of chemistry rather than medicine. It was named after Gilbert N. Lewis, who proposed the concept in 1923. A Lewis acid is defined as an electron-pair acceptor in a chemical reaction. In simpler terms, it's a molecule or ion that can accept a pair of electrons from another molecule or ion to form a covalent bond. Common examples of Lewis acids include aluminum chloride (AlCl3), boron trifluoride (BF3), and iron(III) chloride (FeCl3).

In the Liebeskind-Srogl coupling a thiol ester is coupled with a boronic acid to produce a ketone. The boronic acid organic ... Several synthetic routes are now in common use, and many air-stable boronic acids are commercially available. Boronic acids ... "Boronic Acids". doi:10.1351/goldbook.B00714 Garner, C. W. (10 June 1980). "Boronic acid inhibitors of porcine pancreatic lipase ... A boronic acid is an organic compound related to boric acid (B(OH)3) in which one of the three hydroxyl groups (−OH) is ...
... is a white powder and is commonly used in organic synthesis. Boronic acids are mild Lewis acids which are ... Phenylboronic acid or benzeneboronic acid, abbreviated as PhB(OH)2 where Ph is the phenyl group C6H5-, is a boronic acid ... The dehydration of boronic acids gives boroxines, the trimeric anhydrides of phenylboronic acid. The dehydration reaction is ... Petasis, N. A.; Xavialov, I. A. (1997). "A New and Practical Synthesis of α-Amino Acids from Alkenyl Boronic Acids". J. Am. ...
A second equivalent of boronic acid is needed to break the copper sulfur bond and liberate copper back into the catalytic cycle ... The third generation renders the reaction catalytic in copper and uses only one equivalent of boronic acid by mimicking the ... The third generation renders the reaction catalytic in copper while using only one equivalent of boronic acid. The proposed ... Second generation approach renders the reactions catalytic in copper by using an extra equivalent of boronic acid under aerobic ...
Different boronic acid derivatives have the potential to be tailored to the many different isoforms of beta-lactamases, and ... Has a boronic acid core. Bacteria that can produce beta-lactamases include, but are not limited to:[citation needed] ... and monobactams.Boronic acid derivatives are currently under vast and extensive research as novel active site inhibitors for ... This is a favorable drug design over many clinically used competing agents, because most of them, such as clavulanic acid, ...
ref 29 Winkle, D. (2001). "boronic acids can be used as viable alternatives to borinic acids in suzuki coupling reactions". ... Diphenylborinic acid can catalyse the condensation of pyruvic acids with aldehydes to yield substituted isotetronic acid. ... Borinic acid, also known as boronous acid, is an oxyacid of boron with formula H 2BOH. Borinate is the associated anion of ... Delbrayelle, Dominique (15 June 2010). "Boronic Acids Manufacture at Industrial Scale" (PDF). Archived from the original (PDF) ...
His research was in molecular recognition and catalysis, and he was a user of boronic acid derivatives. He was a former ... He is the principal investigator of a JDRF project focused on translating boronic acid-mediated recognition to smart drug ... Fossey, John S.; Male, Louise; Zhai, Wenlei (2017). "Glucose selective bis-boronic acid click-fluor". ChemComm. 53 (14): 2218- ...
Variations include another CF3 donor potassium (trifluoromethyl)trimethoxyborate, the use of aryl boronic acids or the use of a ... Chu, L.; Qing, F.-L. (2010). "Copper-mediated oxidative trifluoromethylation of boronic acids". Org. Lett. 12 (21): 5060-5063. ... Ruppert's reagent has been used for this purpose in an asymmetric induction approach to functionalise chiral amino acid ... Substrates are thiols, alcohols, phosphines, (hetero) arenes, unactivated olefins and unsaturated carboxylic acids. The ...
In addition to protein as the glucose-binding moiety, boronic acid functionalized molecules have been used. Boronic acid binds ... The use of the boronic acid group for the recognition of saccharide has been widely studied by Shinkai, James and their ... An alternative use of boronic acid in hydrogels is seen in Stokke in Norway where the swelling of a boronate functionalized ... Gamsey, S., et al., Continuous glucose detection using boronic acid-substituted viologens in fluorescent hydrogels: linker ...
Boronic acid self-condensation or condensation with diols is a well-documented dynamic covalent reaction. The boronic acid ... Boronic acid dehydration, as demonstrated by Yaghi et al. is the most common type of reaction used. COFs have been used in gas ... Boronic acid condensation (BAC) and disulfide exchange constitute the two main reactions in this category. Disulfides can ... Nishiyabu, Ryuhei; Kubo, Yuji; James, Tony D.; Fossey, John S. (2011-01-28). "Boronic acid building blocks: tools for self ...
R. Nishiyabu, Y. Kubo, T.D. James and J. S. Fossey (2011). "Boronic acid building blocks: tools for self assembly". Chem. ... The Lewis acid properties of B(CH3)3 have been analyzed by the ECW model yielding EA= 2.90 and CA= 3.60. When trimethylborane ... Trimethylborane is a strong Lewis acid. B(CH3)3 can form an adduct with ammonia: (NH3):B(CH3)3. as well as other Lewis bases. ... "The Reactions of Trimethyl group Va Lewis Bases with simple Boron Lewis Acids" (PDF). Archived from the original (PDF) on 2011- ...
Compounds of the type BRn(OR)3-n are called borinic esters (n = 2), boronic esters (n = 1), and borates (n = 0). Boronic acids ... Boronic acids RB(OH)2 react with potassium bifluoride K[HF2] to form trifluoroborate salts K[RBF3], precursors to nucleophilic ... In the Suzuki reaction, an aryl- or vinyl-boronic acid couples to an aryl- or vinyl-halide through a palladium(0) complex ... Hall, Dennis G. Boronic Acids: Preparation, Applications in Organic Synthesis and Medicine. ISBN 3-527-30991-8 Segawa Yasutomo ...
Schmidt P, Stress C, Gillingham D (June 2015). "Boronic acids facilitate rapid oxime condensations at neutral pH". Chemical ... and aryl boronic acids, which can be achieved through genetic code expansion or post-translational modifications. ... where diverse electrophiles such as aryl halides and aryl boronic acids (an example shown below) have been used to transfer the ... several N-terminal amino acids can undergo transamination to yield N-terminal aldehyde, such as glycine and aspartic acid ( ...
These compounds are solids that are usually in equilibrium with their respective boronic acids at room temperature. Beside ... As discovered in the 1930s, boroxines are produced from their corresponding boronic acids by dehydration. This dehydration can ... Hall, Dennis G. (2005). Boronic Acids - Preparation and Applications in Organic Synthesis and Medicine. John Wiley & Sons ISBN ... Boroxine derivatives (boronic anhydrides) such as trimethylboroxine and triphenylboroxine also make up a broader class of ...
"Discovery of boronic acids as novel and potent inhibitors of fatty acid amide hydrolase". Journal of Medicinal Chemistry. 51 ( ... 4-Nonylphenylboronic acid is a potent and selective inhibitor of the enzyme fatty acid amide hydrolase (FAAH), with an IC50 of ... "Design and synthesis of boronic acid inhibitors of endothelial lipase". Bioorganic & Medicinal Chemistry Letters. 22 (3): 1397- ...
... also known as the Chan-Evans-Lam coupling is a cross-coupling reaction between an aryl boronic acid and an alcohol or an amine ... is coupled with aryl boronic acid, 2, to afford product 3, which is then carried forward to the target 4. The nitrile group of ... Boronic Acids: Preparation and Applications in Organic Synthesis, Medicine and Materials. Wiley-VCH. pp. 315-361. doi:10.1002/ ... Copper-Promoted C-Heteroatom Bond Cross-Coupling Reactions with Boronic Acids and Derivatives". In Dennis G. Hall (ed.). ...
Cox JD, Kim NN, Traish AM, Christianson DW (November 1999). "Arginase-boronic acid complex highlights a physiological role in ... In contrast, inhibiting arginase with ABH or other boronic acid inhibitors will maintain normal cellular levels of arginine, ... Additionally, 2(S)-amino-6-boronohexonic acid (ABH) is an L-arginine analogue that also creates a tetrahedral intermediate ...
Boronic Acids: Preparation and Applications in Organic Synthesis, Medicine and Materials. Wiley-VCH. pp. 315-361. doi:10.1002/ ... Copper-Promoted C-Heteroatom Bond Cross-Coupling Reactions with Boronic Acids and Derivatives". In Dennis G. Hall (ed.). ...
In addition to the organic boronic acid derivatives, which often bind highly specifically to the 1,2-diol groups of sugars, ... Mader, Heike S.; Wolfbeis, Otto S. (2008). "Boronic acid based probes for microdetermination of saccharides and glycosylated ... Concentrated sulfuric acid dissolves dry glucose without blackening at room temperature forming sugar sulfuric acid.[ ... numerous optical probes have also been developed for saccharides based on the use of boronic acids, which are particularly ...
Use of the Hydrogen Bonding of Boronic Acids To Direct Supramolecular Construction". Journal of the American Chemical Society. ... 5-tricarboxylic acid (trimesic acid or TMA). Then Ermer reported an adamantane-1,3,5,7-tetracarboxylic acid (ADTA) based ... Duchamp, D. J.; Marsh, R. E. (1969-01-15). "The crystal structure of trimesic acid (benzene-1,3,5-tricarboxylic acid)". Acta ... Herbstein, F. H.; Kapon, M.; Reisner, G. M. (1987). "Catenated and non-catenated inclusion complexes of trimesic acid". Journal ...
Boronic esters and organotrifluoroborate salts may be used instead of boronic acids. The catalyst can also be a palladium ... Boronic acids are less toxic and safer for the environment than organotin and organozinc compounds. It is easy to remove the ... A wide variety of reagents can be used for the Suzuki coupling, e.g., aryl- or vinyl-boronic acids and aryl- or vinyl-halides. ... The Suzuki reaction was once limited by high levels of catalyst and the limited availability of boronic acids. Replacements for ...
Metal-binding interactions, host-guest, and boronic acid-based chemistries are widely studied as non-covalent conjugation ... "Exploiting the Reversible Covalent Bonding of Boronic Acids: Recognition, Sensing, and Assembly". Accounts of Chemical Research ... Both doxycycline (DOX) and folic acid were incorporated onto the surface of protein covalently. The very low toxicity of ... By incorporating pH responsive poly(propylacrylic acid) (PPAAc) into the system, tumor cell suppressor p53 and cytochrome C can ...
"Enantioselective Redox-Relay Oxidative Heck Arylations of Acyclic Alkenyl Alcohols using Boronic Acids". Journal of the ... In the conjugate addition case, intermediate 34 can be intercepted with formic acid to form a palladium complex (35) that can ... and formic acid additive. Under these conditions, the conjugate addition product is formed preferentially to the vinylic ... Minnaard and coworkers have introduced systems that do not require the addition of formic acid or tributylamine additives. In ...
"Dynamic combinatorial chemistry employing boronic acids/boronate esters leads to potent oxygenase inhibitors". Angew. Chem. Int ... is held by two histidine residues and one aspartic acid/glutamic acid residue. The N2O triad binds to one face of the Fe center ... The active site contains a highly conserved 2-His-1-carboxylate (HXD/E...H) amino acid residue triad motif, in which the ... Sesti C, Simkhovich BZ, Kalvinsh I, Kloner RA (Mar 2006). "Mildronate, a novel fatty acid oxidation inhibitor and antianginal ...
... , also known as fulvestrant-3-boronic acid, is a synthetic, steroidal, orally active antiestrogen which is under ... It is an analogue of fulvestrant in which the C3 hydroxyl group has been replaced with a boronic acid moiety. In accordance, ... "Fulvestrant-3 Boronic Acid (ZB716): An Orally Bioavailable Selective Estrogen Receptor Downregulator (SERD)". J. Med. Chem. 59 ... Boronic acids, Estranes, Experimental cancer drugs, Hormonal antineoplastic drugs, Organofluorides, Organosulfur compounds, ...
Fluorination of Boronic Acids". Organic Letters. 17 (23): 5780-5783. doi:10.1021/acs.orglett.5b02875. ISSN 1523-7060. PMC ... Cyanation of Arylboronic Acids and Arylstannanes," Org. Lett. 2018, 20, 1530-1533. Hendricks, K. H.; Robinson, S. G.; Braten, M ... Cyanation of Arylboronic Acids and Arylstannanes". Organic Letters. 20 (6): 1530-1533. doi:10.1021/acs.orglett.8b00242. ISSN ... "Base-free nickel-catalysed decarbonylative Suzuki-Miyaura coupling of acid fluorides," Nature 2018, 563, 100-104. Aguilera, E. ...
Boronate affinity electrophoresis utilizes boronic acid infused acrylamide gels to purify NAD-RNA. This purification allows for ... Nucleic acids or nucleic acid fragments may be characterized by their affinity to other molecules. The methods have been used ... agarose gel electrophoresis is used to separate protein-bound amino acid complexes from free amino acids. Using a low voltage ... Serum proteins, hemoglobin, nucleic acids, polymerase chain reaction products, etc. are all separated using this method. ...
... boronic acids and stannanes, as well as new methods for radiofluorination of C-H bonds and aryl halides. Scott has also ... Fluorination of Boronic Acids". Organic Letters. 17 (23): 5780-5783. doi:10.1021/acs.orglett.5b02875. ISSN 1523-7060. PMC ... Cyanation of Arylboronic Acids and Arylstannanes". Organic Letters. 20 (6): 1530-1533. doi:10.1021/acs.orglett.8b00242. ISSN ...
"Dynamic combinatorial chemistry employing boronic acids/boronate esters leads to potent oxygenase inhibitors". Angew. Chem. Int ... When a DCL is exposed to an external influence (such as proteins or nucleic acids), the equilibrium shifts and those components ... such as nucleic acids) to influence the evolution and generation of components within a DCL. Protein-directed DCC provides a ... "Enzymatic generation and in situ screening of a dynamic combinatorial library of sialic acid analogues". Angew. Chem. Int. Ed. ...
"Dynamic combinatorial chemistry employing boronic acids/boronate esters leads to potent oxygenase inhibitors". Angew. Chem. Int ... Recent areas of interest include the fat mass and obesity protein which was shown to be a nucleic acid demethylase and JMJD6 ... "Clavulanic Acid Dehydrogenase: Structural and Biochemical Analysis of the Final Step in the Biosynthesis of the β-Lactamase ... Nucleic Acids Research. 42 (7): 4741-4754. doi:10.1093/nar/gku085. ISSN 0305-1048. PMC 3985658. PMID 24489119. Mackeen, Mukram ...
In the Suzuki reaction, boronic esters and boronic acids serve as nucleophilic coupling partners. Expanding the scope of ... Kirchhoff, Jan H.; Netherton, Matthew R.; Hills, Ivory D.; Fu, Gregory C. (2002). "Boronic Acids: New Coupling Partners in Room ...
... is a chemical reagent which can be used to prepare boronic acids. The reaction of boron trichloride with ... On a new boric acid ('Sub-boric acid') of the formula H4B2O4 and its esters]. Ber. Dtsch. Chem. Ges. A/B (in German). 70 (6): ... "Hypodiboric acid". IUPAC. Little, Sarah; Trice, Jane (2001). "Tetrahydroxydiboron". Encyclopedia of Reagents for Organic ... to produce what they termed sub-boric acid. The methanol used in this process can be recycled: BCl3 → − HCl + CH 3 OH {\ ...
The organotrifluoroborate hydrolyses to the corresponding boronic acid in situ, so a boronic acid can be used in place of an ... Boronic acids RB(OH)2 react with potassium bifluoride K[HF2] to form trifluoroborate salts K[RBF3]. Organotrifluoroborates are ... They are often used in organic synthesis as alternatives to boronic acids (RB(OH)2), boronate esters (RB(OR′)2), and ... Molander, Gary A.; Ellis, Noel (2007). "Organotrifluoroborates: Protected Boronic Acids That Expand the Versatility of the ...
In the Liebeskind-Srogl coupling a thiol ester is coupled with a boronic acid to produce a ketone. The boronic acid organic ... Several synthetic routes are now in common use, and many air-stable boronic acids are commercially available. Boronic acids ... "Boronic Acids". doi:10.1351/goldbook.B00714 Garner, C. W. (10 June 1980). "Boronic acid inhibitors of porcine pancreatic lipase ... A boronic acid is an organic compound related to boric acid (B(OH)3) in which one of the three hydroxyl groups (−OH) is ...
21st Century Boronic Acids as Catalysts Applications of boronic acids in chemical biology and medicinal chemistry Boronic Acids ... Boronic Acids Derivatives as Catalysts (Yamamoto and Payette) Applications of Boronic Acids in Chemical Biology and Medicinal ... Boronic Acids and Derivatives Transition-Metal Catalyzed Desulfitative Coupling of Thioorganic Compounds with Boronic Acids ... Produktinformationen zu „Boronic Acids (ePub)". The past two decades have witnessed phenomenal advances in the synthetic, ...
... boronic acid" Detailed information of the J-GLOBAL is a service based on the concept of Linking, Expanding, and Sparking, ...
Christian Klein reports on the synthesis of peptide-boronic acids by a versatile building-block approach. ... Christian Klein reports on the synthesis of peptide-boronic acids by a versatile building-block approach. ... Their focus is on viral serine proteases, such as from the dengue, Zika, and West Nile viruses, where peptide-boronic acids ... Read the full article Diversity-Oriented Synthesis of Peptide-Boronic Acids by a Versatile Building-Block Approach ...
2-Methylpyrimidine-5-boronic acid, AOBCHEM USA 18037-1G. 1034924-06-5. MFCD07375144   at ... Aobchem 2-Methylpyrimidine-5-boronic acid, AOBCHEM USA 18037-1G. 1034924-06-5. MFCD07375144 ... 2-Methylpyrimidine-5-boronic acid, AOBCHEM USA 18037-1G. 1034924-06-5. MFCD07375144 ...
boronic acid Boronic acid, [1-[[. 3-(1-naphthalenyl)-. 2-[(4-morpholinyl c. arbonyl)amino]-1-ox. opropyl]amino]-3-me. thylbutyl ... UTYLBORONIC ACID [(1R)-3-Methyl-1-{[. N-(4-morpholinylcar. bonyl)-3-(1-naphthy. l)-D-alanyl]amino}b. utyl]boronic acid [ACD/ ... NE BORONIC ACID (1R)-3-methyl-1-[(2. R)-2-(morpholine-4-. carbonylamino)-3-(n. aphthalen-1-yl)prop. anamido]butylboroni. c acid ... Boronic acid, B-[(1. R)-3-methyl-1-[[(2R. )-2-[(4-morpholinyl. carbonyl)amino]-3-(. 1-naphthalenyl)-1-o. xopropyl]amino]buty. l ...
Find manufacturers and suppliers for 6-Formylpyridine-2-boronic acid pinacol ester. Synonyms: 6-(4,4,5,5-Tetramethyl-[1,3,2] ... Suppliers of 6-Formylpyridine-2-boronic acid pinacol ester. Supplier:. Combiphos Catalysts. ... 4-Cyanopyridine-2-boronic acid pinacol ester. *Methyl pyridine-2-boronic acid pinacol ester-6-carboxylate ... 5-Formylpyridine-2-boronic acid pinacol ester. *6-Chloropyridine-2-boronic acid pinacol ester ...
The polyol and boronic acid receptor classes are investigated here to recognize the chloride (Cl−); fluoride (F−); dihydrogen ... The polyol-Cl− interactions are more attractive than the boronic acid-Cl− bond. Boronic acid recognizes F− and H2PO4− with the ... by boronic acid involves B⋯F− and B⋯O−-P bonds, respectively, showing a larger covalent character compared to other boronic ... The polyol and boronic acid receptor classes are investigated here to recognize the chloride (Cl−); fluoride (F−); dihydrogen ...
5-CHLOROPYRIDINE-2-BORONIC ACID PINACOL ESTER) for price inquiry. where to buy 652148-93-1(5-CHLOROPYRIDINE-2-BORONIC ACID ... 5-CHLOROPYRIDINE-2-BORONIC ACID PINACOL ESTER) including MSDS sheet(poisoning, toxicity, hazards and safety),chemical ... 5-CHLOROPYRIDINE-2-BORONIC ACID PINACOLATE;5-CHLOROPYRIDINE-2-BORONIC ACID PINACOL ESTER;3-CHLORO-6-(4,4,5,5-TETRAMETHYL-[1,3,2 ... 5-Chloropyridine-2-boronic acid pinacolateAppearance:detailed see specifications Storage:Keep away of light, cool place Package ...
Find manufacturers and suppliers for 5-Trifluoromethylpyridine-2-boronic acid pinacol ester. Synonyms: 2-(4,4,5,5-Tetramethyl-[ ... Suppliers of 5-Trifluoromethylpyridine-2-boronic acid pinacol ester. Supplier:. Combiphos Catalysts. ... 2-Aminocyclohexanecarboxylic acid. *6-Bromopyridine-2-boronic acid pinacol ester. *4-Fluoropyridine-2-boronic acid pinacol ... 3-Fluoropyridine-2-boronic acid pinacol ester. *5-Fluoropyridine-2-boronic acid pinacol ester ...
The use of boronic acids to bind saccharides has been investigated for many years as a facile means to monitor the ... Boronic Acids; Hydrogels; Stimuli-responsive; Sensors; Glucose; Diols. Subjects:. Physical Sciences , Analytical chemistry. ... Herein we present a family of novel boronic acid derivatives, using an easily-adaptable synthesis. We demonstrate a suite of ... ORCID: 0000-0003-2944-4839 (2018) Boronic acids for the generation of responsive hydrogels. In: Analytical and Nanoanalytical ...
Record for Phenoxathiin-4-boronic acid, CAS Number 100124-07-0, MDL Number MFCD01605731. ... Benzoic Acids. Boronic Acids. Fluorophenylacetic Acids. Indoles. Ligands for Suzuki Coupling. Pyridinecarboxylic Acids. ...
Glucose Sensing, Fluorescence, Boronic Acids. Subjects:. Engineering , Materials. Medical Sciences , Diseases. Physical ... Boronic acids (BAs) are well--known for their interactions with diol--containing compounds like glucose. Fluorescent moieties ... ORCID: 0000-0003-2944-4839 (2017) Novel chemical sensors using boronic acids for glucose detection. In: 69th Irish Universities ...
[2377611-41-9], MFCD32065671, (2-Fluoro-3-formyl-6-methoxyphenyl)boronic acid
FURAN-2-BORONIC ACID for pharmaceutical, agricultural and life science industries. We provide CAS 98437-24-2 MSDS, Certificate ...
Typically In-Stock , CAS: 846548-44-5 , (2,6-dimethylpyridin-4-yl)boronic acid , MF: C7H10BNO2 , MW: 150.97
This project will screen numerous boronic acid derivatives available at the Research School of Chemistry (optional: ... Boronic acids are frequently used in cross-coupling reactions (Suzuki). Therefore, this project will screen numerous boronic ... We have established peptide-based inhibitors featuring boronic acids. These compounds are highly active but offer only limited ... This project will screen numerous boronic acid derivatives available at the Research School of Chemistry (optional: ...
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4-[(4-Methylpiperazin-1-yl)methyl]benzoic acid dihydrochloride C13H20Cl2N2O2 92737-01-4 1-BROMO-3,3,4,4,4-PENTAFLUORO-2- ...
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Field-effect saccharide sensing using AlGaN/GaN heterostructures and boronic acid based chemical receptors. In: Sensors and ... keywords = "GaN, biosensors, saccharide, boronic acid, FET",. author = "Schuller, {T A} and M Kuball and Flower, {Stephen E} ... Field-effect saccharide sensing using AlGaN/GaN heterostructures and boronic acid based chemical receptors. / Schuller, T A; ... Field-effect saccharide sensing using AlGaN/GaN heterostructures and boronic acid based chemical receptors. Sensors and ...
Find trusted boronic acid for sale. Any requirements and problems can ask us at any time. ... Boronic Acids and Esters. Boronic acids and boronate esters are commonly used reagents in Suzuki-Miyaura coupling chemistry. ... Aliphatic Chain Compounds Borates Boronic Acids and Esters Bridged Compounds Catalysts and Ligands Fluorinated Compounds Spiro ... Boronic esters and acids are potential intermediates in the manufacture of many active pharmaceutical ingredients (API). ...
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  • Furthermore, boronic acid derivatives constitute a class of inhibitors for human acyl-protein thioesterase 1 and 2, which are cancer drug targets within the Ras cycle. (
  • However, a significant fraction of commonly used boronic acids and their derivatives were recently found to gives a positive Ames test and act as chemical mutagens. (
  • The past two decades have witnessed phenomenal advances in the synthetic, biological, and medicinal applications of organoboronic acid derivatives. (
  • The renowned boron chemist Prof. Dennis Hall is joined by a select group of expert authors to cover all modern aspects of boronic acid derivatives in one comprehensive handbook. (
  • Herein we present a family of novel boronic acid derivatives, using an easily-adaptable synthesis. (
  • This project will screen numerous boronic acid derivatives available at the Research School of Chemistry (optional: computational screening of data banks). (
  • Two redemitting BODIPY boronic acid pinacolate derivatives, sensors 1 and 2 were shown to act as excellent and highly selective lactate detectors at physiological pH (7.4), where the formed sensor-lactate complexes exhibited a significant emission and absorption increase. (
  • An alternative to esters in this method is the use of diboronic acid or tetrahydroxydiboron ([B(OH2)]2). (
  • Boronic esters are esters formed between a boronic acid and an alcohol. (
  • Boronic acids and boronate esters are commonly used reagents in Suzuki-Miyaura coupling chemistry. (
  • Boronic esters and acids are potential intermediates in the manufacture of many active pharmaceutical ingredients (API). (
  • Boronic acids are used extensively in organic chemistry as chemical building blocks and intermediates predominantly in the Suzuki coupling. (
  • Boronic acids are used in organic chemistry in the Suzuki reaction. (
  • As a result, most chemists in academia and industry now make use of boronic acids in synthetic chemistry, be it for Suzuki-Miyaura cross-coupling or other reactions. (
  • These results provide proof-of-concept for the development AlGaN/GaN-based sensor devices incorporating boronic acid receptor chemistry. (
  • A Ni 0 catalyst complexed with a biaryldialkyl monophosphine ligand facilitates C-C bond formation between styrenyl epoxides and aryl boronic acids (see scheme). (
  • The pKa of a boronic acid is ~9, but they can form tetrahedral boronate complexes with pKa ~7. (
  • Chemical derivatization of catecholamines was performed by a reaction with a synthesized permanent pyridinium- cation -containing boronic acid molecule, 4-( N-methyl)pyridinium boronic acid , through boronate ester formation ( boronic acid -diol reaction). (
  • In this analytical technique, a boronate such as phenylboronic acid is bonded to the surface of the column support. (
  • For example, phenylboronic acid is produced from phenylmagnesium bromide and trimethyl borate followed by hydrolysis PhMgBr + B(OMe)3 → PhB(OMe)2 + MeOMgBr PhB(OMe)2 + 2 H2O → PhB(OH)2 + 2 MeOH Another method is reaction of an arylsilane (RSiR3) with boron tribromide (BBr3) in a transmetallation to RBBr2 followed by acidic hydrolysis. (
  • Phenylboronic acid can be selfcondensed to the cyclic trimer called triphenyl anhydride or triphenylboroxin. (
  • Boronic acids (BAs) are well--known for their interactions with diol--containing compounds like glucose. (
  • In the Liebeskind-Srogl coupling a thiol ester is coupled with a boronic acid to produce a ketone. (
  • Christian Klein reports on the synthesis of peptide-boronic acids by a versatile building-block approach. (
  • According to Professor Klein "the synthesis of these peptide-boronic acids from our group was highly challenging, involving multiple steps and encountering obstacles caused by, for example, difficulties in removing the pinanediol or pinacol protecting groups from the boronic acid function. (
  • The use of boronic acids to bind saccharides has been investigated for many years as a facile means to monitor the concentration of sacharrides in solution [2]. (
  • Nielsen, DK & Doyle, AG 2011, ' Nickel-catalyzed cross-coupling of styrenyl epoxides with boronic acids ', Angewandte Chemie - International Edition , vol. 50, no. 27, pp. 6056-6059. (
  • A boronic acid is an organic compound related to boric acid (B(OH)3) in which one of the three hydroxyl groups (−OH) is replaced by an alkyl or aryl group (represented by R in the general formula R−B(OH)2). (
  • As an important boric acid, customized boric acid. (
  • Boronic acids are known to bind to active site serines and are part of inhibitors for porcine pancreatic lipase, subtilisin and the protease Kex2. (
  • The work of Professor Christian Klein's group at Heidelberg University (Germany) has been motivated by their interest in peptide-boronic acids (PBAs) as serine protease inhibitors. (
  • We have established peptide-based inhibitors featuring boronic acids. (
  • Furthermore, no inhibitors are available for de- tecting OXA-48-type producers that are spreading rapidly, To rapidly identify carbapenemase producers in En- at least in northern Africa, the Middle East, and Europe ( 2 ). (
  • ORCID: 0000-0003-2944-4839 (2017) Novel chemical sensors using boronic acids for glucose detection. (
  • 4-( N-Methyl)pyridinium boronic acid worked as a reactive matrix for catecholamines with LDI and improved the sensitivity of detection for both SIMS and LDI, while the isotopic abundances of the boron atom reflect a unique isotopic pattern for derivatized catecholamines in MS analysis . (
  • Their focus is on viral serine proteases, such as from the dengue, Zika, and West Nile viruses, where peptide-boronic acids were instrumental in the determination of crystal structures. (
  • Boronic acids are frequently used in cross-coupling reactions (Suzuki). (
  • Several synthetic routes are now in common use, and many air-stable boronic acids are commercially available. (
  • This in turn has created a new market for suppliers of functionalized boronic acids. (
  • 1.5E6 OH/cm3) Half-Life = 0.972 Hrs Ozone Reaction: No Ozone Reaction Estimation Fraction sorbed to airborne particulates (phi): 1 (Junge,Mackay) Note: the sorbed fraction may be resistant to atmospheric oxidation Soil Adsorption Coefficient (PCKOCWIN v1.66): Koc : 1.944E+005 Log Koc: 5.289 Aqueous Base/Acid-Catalyzed Hydrolysis (25 deg C) [HYDROWIN v1.67]: Rate constants can NOT be estimated for this structure! (
  • In 1860, Edward Frankland was the first to report the preparation and isolation of a boronic acid. (
  • The polyol-Cl − interactions are more attractive than the boronic acid-Cl − bond. (
  • The compound bortezomib with a boronic acid group is a drug used in chemotherapy. (
  • The boronic acid functional group is reputed to have low inherent toxicity. (
  • On-Tissue Chemical Derivatization of Catecholamines Using 4-( N-Methyl)pyridinium Boronic Acid for ToF-SIMS and LDI-ToF Mass Spectrometry Imaging. (
  • Boronic acids can be obtained via several methods. (
  • The mechanism of mutagenicity is thought to involve the generation of organic radicals via oxidation of the boronic acid by atmospheric oxygen. (
  • ORCID: 0000-0003-2944-4839 (2018) Boronic acids for the generation of responsive hydrogels. (
  • Boronic acids typically have high melting points. (