This paper deals with the synthesis and characterization of a macrocyclic ligand (L) and its new-fangled complex compounds of the general formula [M-L Cl|sub|2|/sub|] for M= Ru(III), and [M-L] for Pt(II) and Pd(II) where L is a macrocyclic ligand resulted from the condensation reaction of ethylene diamine and ethyl acetoacetate. The ligand and its coordination compounds are formulated according to the chemical analysis, electronic, infrared, |sup|1|/sup|HNMR and mass spectra, as well as magnetic susceptibility values.
Author(s): Shen, Xiao; Nguyen, Thach T; Koh, Ming Joo; Xu, Dongmin; Speed, Alexander WH; Schrock, Richard R; Hoveyda, Amir H | Abstract: Macrocyclic compounds are central to the development of new drugs, but preparing them can be challenging because of the energy barrier that must be surmounted in order to bring together and fuse the two ends of an acyclic precursor such as an alkene (also known as an olefin). To this end, the catalytic process known as ring-closing metathesis (RCM) has allowed access to countless biologically active macrocyclic organic molecules, even for large-scale production. Stereoselectivity is often critical in such cases: the potency of a macrocyclic compound can depend on the stereochemistry of its alkene; alternatively, one isomer of the compound can be subjected to stereoselective modification (such as dihydroxylation). Kinetically controlled Z-selective RCM reactions have been reported, but the only available metathesis approach for accessing macrocyclic E-olefins entails
This book describes the coordination chemistry of macrocyclic ligands. Common types of ligands are introduced and strategies for the synthesis of the free ligands and their metal complexes are discussed. The unique thermodynamic and kinetic properties of macrocyclic complexes are introduced and applications of the ligands presented.
A compound as represented by Formula (I) is provided, wherein groups are defined in the description. The compound is used as HCV protease inhibitor for treating HCV infection.
1. A compound of Formula I: ##STR05233## whereinA is absent or selected from --(C═O)--, --S(O)2, --C═N--OR1 and --C(═N--CN);Z201 is absent or selected from --C1-C8 alkylene, --C2-C8 alkenylene, or --C2-C8 alkynylene each containing 0, 1, 2, or 3 heteroatoms selected from O, S, or N; substituted --C1-C8 alkylene, including but not limited to halogenated --C1-C8 alkylene, substituted --C2-C8 alkenylene, including but not limited to halogenated --C2-C8 alkenylene or substituted --C2-C8 alkynylene, including but not limited to halogenated --C2-C8 alkynylene each containing 0, 1, 2, or 3 heteroatoms selected from O, S or N; --C3-C12 cycloalkylene, or --C3-C12 cycloalkenylene each containing 0, 1, 2, or 3 heteroatoms selected from O, S or N; substituted --C3-C12 cycloalkylene, including but not limited to halogenated --C3-C12 cycloalkylene, or substituted --C3-C12 cycloalkenylene, including but not limited to halogenated --C3-C12 cycloalkenylene each containing 0, 1, 2, or 3 heteroatoms selected ...
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Cyclopeptide alkaloids are polyamidic, macrocyclic compounds, containing a 13-, 14-, or 15-membered ring. The ring system consists of a hydroxystyrylamine moiety, an amino acid, and a β-hydroxy amino acid; attached to the ring is a side chain, comprised of one or two more amino acid moieties. In vitro antiplasmodial activity was shown before for several compounds belonging to this class, and in this paper the antiplasmodial and cytotoxic activities of ten more cyclopeptide alkaloids are reported. Combining these results and the IC50 values that were reported by our group previously, a library consisting of 19 cyclopeptide alkaloids was created. A qualitative SAR (structure-activity relationship) study indicated that a 13-membered macrocyclic ring is preferable over a 14-membered one. Furthermore, the presence of a β-hydroxy proline moiety could correlate with higher antiplasmodial activity, and methoxylation (or, to a lesser extent, hydroxylation) of the styrylamine moiety could be important for
Source: Angew Chem Int Ed Engl. 2016 Sep 14. doi: 10.1002/anie.201607188. Abstract Macrocyclic compounds have received increasing attention in recent years.
Control of slow wave frequency in cat small intestinal muscle was investigated with microelectrodes. Exposure of intact muscle or isolated longitudinal muscle to low Ca(2+) saline decreased slow wave frequency with less than a 6 mV change in resting potential. This frequency decline was characterized by a prolongation of the diastolic phase of the slow wave. Raising Ca(,0)(2+) to 2-3 times normal increased slow wave frequency. At Ca(,0)(2+) greater than 4 times normal, the slow wave frequency again decreased. However, this decrease in frequency was characterized by a prolongation of the systolic phase of the waveform. Application of Ca conductance blockers (Co(2+), Mn(2+), D600, verapamil), increasing Mg(,0)(2+) or increasing internal pH decreased slow wave frequency by a prolongation of the diastolic region of the slow wave. Addition of db-cAMP to Krebs saline made hypertonic with sucrose or decreasing internal pH increased slow wave frequency. These results indicate a relationship ...
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Since the discovery of penicillin, bacteria have counteracted the action of antibiotics leading to a worrisome situation about antibiotic efficiency. During our research on non-traditional 1,3-bridged β-lactams embedded into macrocycles as potential inhibitors of Penicillin Binding Proteins (PBPs), we unexpectedly synthesized bis-2-oxoazetidinyl macrocycles arising from a dimerization reaction under ring closing metathesis (RCM) conditions. These molecules were revealed to be good inhibitors of the d,d-peptidase from Actinomadura R39, which is commonly used as a model of PBPs. To pursue the research on this type of novel compounds, a complete family of cyclodimers 4 and 5 was synthesized and evaluated against R39, and high molecular weight d,d-peptidases: PBP2a of methicillin-resistant Staphylococcus aureus and PBP5 of resistant Enterococcus faecium. Some bis-2-oxoazetidinyl macrocycles exhibited very promising activities against PBP2a. In order to explain the biological results, docking ...
The geometry and electronic structure of several phosphinine-ether macrocycles were investigated at semiempirical level. The calculated geometries are in good agreement with experimental data. Compared to phosphinine, the coordinative abilities of phosphinineether macrocycles based on energy considerations suggest a little lowered π acceptor character, while π donor character is improved. The molecular environment causes a significant mixing of phosphinine and phenyl substituent π levels. The geometry and electronic properties of phosphinine-ether macrocycles can provide significant host coordination properties for guest species ...
TY - JOUR. T1 - Enhancement of tyrosinase activity by macrocycles in the oxidation of p-cresol in organic solvents. AU - Broos, Jaap. AU - Arends, Renate. AU - van Dijk, Gerrit B.. AU - Verboom, Willem. AU - Engbersen, Johan F.J.. AU - Reinhoudt, David N.. PY - 1996. Y1 - 1996. N2 - The activity of tyrosinase, suspended in dry halogenated solvents, can be considerably increased upon the addition of macrocycles to the reaction medium.. AB - The activity of tyrosinase, suspended in dry halogenated solvents, can be considerably increased upon the addition of macrocycles to the reaction medium.. KW - IR-10887. U2 - 10.1039/P19960001415. DO - 10.1039/P19960001415. M3 - Article. VL - 1996. SP - 1415. EP - 1417. JO - Journal of the Chemical Society, Perkin Transactions 1. JF - Journal of the Chemical Society, Perkin Transactions 1. SN - 0300-922X. IS - 12. ER - ...
To find and calibrate a robust and reliable computational protocol for mapping conformational space of medium-sized molecules, exhaustive conformational sampling has been carried out for the series of seven macrocyclic compounds of varying ring size and one acyclic analogue. While five of them were taken from the MD/LLMOD/force-field study by Shelley and coworkers (J. Chem. Inf. MODEL: 2014, 54, 2680), three represent potential macrocyclic inhibitors of human cyclophilin A. The free energy values (GDFT/COSMO-RS) for all conformers of each compound were obtained by the composite protocol based on the in vacuo quantum mechanics (DFT-D3 method in a large basis set), standard gas-phase thermodynamics and the COSMO-RS solvation model (QM+COSMO-RS ...
Oxygen adsorption energy is directly relevant to the catalytic activity of electrocatalysts for oxygen reduction reaction (ORR). In this study, we established the correlation between the O{sub 2} adsorption energy and the electronic structure of transition metal macrocyclic complexes which exhibit activity for ORR. To this end, we have predicted the molecular and electronic structures of a series of transition metal macrocyclic complexes with planar N{sub 4} chelation, as well as the molecular and electronic structures for the O{sub 2} adsorption on these macrocyclic molecules, using the density functional theory calculation method. We found that the calculated adsorption energy of O{sub 2} on the transition metal macrocyclic complexes was linearly related to the average position (relative to the lowest unoccupied molecular orbital of the macrocyclic complexes) of the non-bonding d orbitals (d{sub z{sup 2}}, d{sub xy}, d{sub xz}, and d{sub yz}) which belong to the central transition metal atom. ...
The growing antibiotic resistance phenomenon continues to stimulate the search for new compounds and strategies to combat bacterial infections. In this study, we designed and synthesized a new polycationic macrocyclic compound (2) bearing four N-methyldiethanol ammonium groups clustered and circularly organized by
Molecular container mops up tricaine to reverse anaesthesia in fish A lack of clinically available antidotes for general anesthesia has prompted a team of researchers in China and Canada to explore the potential of a macrocyclic compound for halting anesthesia in zebrafish. ...
TY - JOUR. T1 - Nucleotide recognition by macrocyclic receptors. AU - Hamilton, Andrew D.. AU - Muehldorf, Alex. AU - Chang, Suk Kyu. AU - Pant, Nalin. AU - Goswami, Shyamaprosad. AU - van Engen, Donna. PY - 1989/2. Y1 - 1989/2. N2 - It is shown that complementary positioning of recognition sites (particularly hydrogen bonding, stacking and hydrophobic groups) into a macrocyclic structure can lead to very strong and specific complexation of uncharged organic molecules.. AB - It is shown that complementary positioning of recognition sites (particularly hydrogen bonding, stacking and hydrophobic groups) into a macrocyclic structure can lead to very strong and specific complexation of uncharged organic molecules.. KW - Molecular recognition. KW - barbiturate. KW - guanine. KW - nucleotide. KW - thymine. UR - http://www.scopus.com/inward/record.url?scp=1842726319&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=1842726319&partnerID=8YFLogxK. U2 - 10.1007/BF01112780. DO - ...
Macrocycles library is a set of macrocyclic peptidomimetics that are potential PPI modulators. ChemDiv designed unique spiro and fused scaffolds.
A mononuclear side-on peroxocobalt(III) complex with a tetradentate macrocyclic ligand, [CoIII(TBDAP)(O2)]+ (1), shows a novel and facile mode of dioxygenase-like reactivity with nitriles (R - C=N; R = Me, Et, and Ph) to produce the corresponding mononuclear hydroximatocobalt(III) complexes, [CoIII(TBDAP)(R - C(=NO)O)]+, in which the nitrile moiety is oxidized by two oxygen atoms of the peroxo group. The overall reaction proceeds in one-pot under ambient conditions (ca. 1 h, 40 °C). 18O-Labeling experiments confirm that both oxygen atoms are derived from the peroxo ligand. The structures of all products, hydroximatocobalt(III) complexes, were confirmed by X-ray crystallography and various spectroscopic techniques. Kinetic studies including the Hammett analysis and isotope labeling experiments suggest that the mechanistic mode of 1 for activation of nitriles occurs via a concerted mechanism. This novel reaction would be significantly valuable for expanding the chemistry for nitrile activation ...
Registration Institution: Técnico-ULisboa. 7. High-Value Chemicals from Small and Inexpensive Molecules: Activating N2, CO, and CO2 Using Transition Metals. The use of inexpensive and abundant feedstocks in the synthesis of high-value chemicals is a long standing goal in chemistry. In particular, the formation of N-C bonds from N2 and CO or CO2 is appealing since N2 is one of the most abundant molecules on Earth, CO2 is a greenhouse gas and CO is toxic. Using these sources of nitrogen and carbon is challenging, especially N2, one of the most stable molecules known. Success in the formation of these bonds will certainly attract the attention of both industry and academia. This project aims at the development of new group 4 metal catalysts, supported by monoanionic macrocyclic ligands, for N2 activation and subsequent functionalization with CO and CO2. The experimental work will be complemented by theoretical calculations in order to understand the reactivity and mechanisms of activation of these ...
Reactions of nonheme Fe-III-superoxo and Mn-IV-peroxo complexes bearing a common tetraamido macrocyclic ligand (TAML), namely [(TAML)Fe-III(O-2)](2-) and [(TAML)Mn-IV(O-2)](2-), with nitric oxide (NO) afford the Fe-III-NO3 complex [(TAML)Fe-III(NO3)](2-) and the Mn-V-oxo complex [(TAML)Mn-V(O)](-) plus NO2-, respectively. Mechanistic studies, including density functional theory (DFT) calculations, reveal that M-III-peroxynitrite (M=Fe and Mn) species, generated in the reactions of [(TAML)Fe-III(O-2)](2-) and [(TAML)Mn-IV(O-2)](2-) with NO, are converted into M-IV(O) and CNO2 species through O-O bond homolysis of the peroxynitrite ligand. Then, a rebound of Fe-IV(O) with CNO2 affords [(TAML)Fe-III(NO3)](2-), whereas electron transfer from Mn-IV(O) to CNO2 yields [(TAML)Mn-V(O)](-) plus NO2 ...
Gluzinski P.; Krajewski J.; Korybut-Daszkiewicz B.; Mishnev A.; Kemme A. Nickel(II) complexes of tetraaza macrocyclic ligands bearing pedant donor groups. Part III. The X-ray and conformational investigations of high-spin trans-2,9-bis(aminomethyl)-and low-spin trans-2,9-bis(ammoniummeththyl-1,4,8,11-tetraazacyclotetradeca-4,11-dienenickel(II) perchlorates. Pol. J. Chem. 1995, 69(3), 350-360 ...
Fingerprint Dive into the research topics of Chiral nanostructuring of multivalent macrocycles in solution and on surfaces. Together they form a unique fingerprint. ...
As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of K dimer , 10 13 M -1 in CHCl 3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol -1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistent tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3. ...
Dynamic combinatorial libraries (DCLs) are excellent benchmark models to study the stimuli-responsiveness of chemical networks. However, increasingly complex systems are difficult to analyze with simple data analysis methods, because many variables and connections must be considered for their full understanding. Here we propose the use of multivariate data analysis methods to bisect the evolution of a complex synthetic dynamic library of pseudopeptidic macrocycles, containing side chains with ch
Recognizing the potential synergies of linking these together, the researchers prepared a dimer of a related molecule, but unfortunately the affinity of this much larger molecule was actually worse. However, they wisely isolated and tested a side product, compound 4, and found that this had improved potency. A crystal structure of this molecule bound to Mcl-1 revealed that the pocket had expanded to accommodate the added pyrazole moiety. Since compound 4 adopted a U-shaped conformation, the researchers decided to try a macrocyclization strategy to lock this conformation and reduce the entropic penalty of binding. This produced compound 5, and adding a couple more judiciously placed atoms led to AZD5991, with a nearly 300-fold improved affinity. The molecule binds rapidly to Mcl-1 and has a relatively long residence time of about 30 minutes. A crystal structure reveals a close overlay with the initial compound 1 (in cyan). ...
Macrocyclic (E)-alkenylsiloxanes, obtained from E-selective ring-closing metathesis reactions, can be converted to the corresponding (Z)-alkenyl bromides and (E
The Journal of Inclusion Phenomena and Macrocyclic Chemistry is the premier publication reporting on original, interdisciplinary research on all aspects of ...
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We have introduced the fold-in strategy for synthesizing curved aromatic molecules. In this method, a macrocyclic precursor is subjected to a strain-inducing reaction to produce a distorted conjugated structure. The fold-in method is particularly well suited for the synthesis of bowl-shaped (spherical), belt-shaped (tubular) and saddle-shaped (hyperbolic) molecules, but can be just as well applied for the preparation of planar coronoid macrocycles.. Examples of molecules synthesized in our laboratory using the fold-in method include the molecular jellyfish (named chrysaorole), a triangular carbazole belt, and fluorene-containing chrysaorenes. Octulene, the hyperbolic analogue of kekulene, was also obtained in a fold-in reaction, and showed a surprising ability to bind chloride anions. ...
In this contribution, a computational study of equatorial bound tetranuclear macrocycle (butylene linked) [LnZnII3(HOMBu)]3+ (Ln = La3+, Ce3+) complexes was carried out. Here, the electronic structure, bonding interaction and excitation energies were studied within the relativistic density functional theory
4A92: A Macrocyclic Hcv Ns3/4A Protease Inhibitor Interacts with Protease and Helicase Residues in the Complex with its Full- Length Target.
The IP Industry Base is a public available database about the global market of IP practitioners. Currently is provides high-quality profiles of more than 4910 companies, 15620 professionals and 4250 places. The service of the IP Industry Base is dedicated to technology managers, IP professionals and IPR academia. The open data of the IP Industry Base aims to create transparency for the market of IP practitioners.
The structural complexity of beyond-rule-of-5 compounds, such as peptide macrocycles, may facilitate access to additional biological target space beyond the enzymatic active site. Naturally occurring cyclic peptides, in ...
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Bio-Synthesis offers macrocyclic metal chelator conjugation services by covalently attached peptides, antibodies or drugs to those metal chelating ligands
V. V. Gorbatchuk, A. G. Tsifarkin, I. S. Antipin, B. N. Solomonov, A. I. Konovalov, Estimation of Free Energy of Supramolecular Effect at Host - Guest Complex Formation between Solid tert-Butylcalix[4]arene and Vapors of Organic Compounds // J. Inclusion Phenomena Macrocyclic Chem. - 1999. - V. 35, 1/2.- P.389-396 ...
TY - JOUR. T1 - Synthesis of Strained 1,3-Diene Macrocycles via Copper-Mediated Castro-Stephens Coupling/Alkyne Reduction Tandem Reactions. AU - Li, Wei. AU - Schneider, Christopher M.. AU - Georg, Gunda I.. PY - 2015/8/7. Y1 - 2015/8/7. N2 - A copper-mediated macrocyclization involving the reaction of a vinyl iodide and a terminal alkyne followed by an in situ reduction of the enyne intermediate is reported. The reaction generates a conjugated Z-double bond within a strained medium-size lactone, lactam, or ether macrocycle. A variety of macrocyclic compounds bearing different ring sizes and functionalities were synthesized. A complementary stepwise procedure was also developed for less strained ring systems.. AB - A copper-mediated macrocyclization involving the reaction of a vinyl iodide and a terminal alkyne followed by an in situ reduction of the enyne intermediate is reported. The reaction generates a conjugated Z-double bond within a strained medium-size lactone, lactam, or ether ...
The first part of this work deals with the interactions of amino acids and neutral macrocyclic ligands (18-crown-6 and cryptand 222). Solubilities and Gibbs energies of solution of several amino acids and their complexes with 18-crown-6 in acetonitrile, as well as of some amino acid ester salts in chloroform have been determined at 298.15 K. An increase in the solubility data for the amino acid complexes relative to the free amino acids has been found, as a result of the interactions of the guest molecules with the macrocyclic ligands. Stability constants, Gibbs energies, enthalpies and entropies of complexation of a series of L- and D-amino acids with 18-crown-6 and with cryptand 222 in methanol at 298.15 K were obtained by titration calorimetry. The similar Gibbs energies of complexation found for these systems are the result of an enthalpy-entropy compensation effect. No significant differences have been found between the thermodynamic parameters of complexation of the L- and D-amino acids ...
The synthesis of a series of novel macrocyclic compounds designed to target blood coagulation Factor XIa is described. The compounds were evaluated for their inhibition of a small set of serine proteases. Several compounds displayed modest activity and good selectivity for Factor XIa. Within the series, a promising lead structure for developing novel macrocyclic inhibitors of thrombin was identified.. ...
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Selective chelation of bismuth radionuclide ions from a mixture including actinium radionuclide ions involves exposing a ligand to an aqueous solution that includes bismuth radionuclide ions and actinium radionuclide ions under conditions whereby the bismuth radionuclide ions selectively chelate to the ligand for form cationic complexes of the bismuth radionuclide ions. and separating the cationic complexes of the bismuth radionuclide ions from the actinium radionuclide ions. The ligands have a structure based on a 12-membered cyclen ring and may include pendant functional groups that can be derivatized with biological targeting vectors for targeted alpha therapy.
Lanthanide(III) complexes of DOTA derivatives are utilized in the medical imaging techniques such as magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and magnetic resonance spectroscopy (MRS), nuclear imaging (PET and SPECT), or optical methods (luminescence). It has been shown that relaxometric parameters of the Gd(III) complexes of DOTA derivatives with a phosphinic acid pendant arm (Gd-DO3APR ) can reach optimal values (e.g. water residence time, τM, being close to ~10 ns). The relaxometric parameters can be further modified through the phosphorus substituents. It is also known that the complexes possess a high thermodynamic stability and they are kinetically inert. The main goal of this Thesis is an investigation of the effect of pendant amino group protonation in substituents bound to the phosphorus atom on properties of the complexes. Thus in this Thesis, DOTA derivatives with the phosphinic acid pendant arm with an amino group and their complexes were prepared and ...
Dominique Kunciw [2013] is looking to find new ways to fight cancer through computational analysis and synthetic chemistry to discover what turns a healthy cell cancerous.. She will present her work on a gene strongly implicated in breast cancer and several other cancers, such as skin cancer, at the Royal Society of Chemistrys 8th annual Biological and Medicinal Chemistry Postgraduate Symposium on 12 December.. Her PhD project, entitled Multi-pharmacophore Modeling and Synthesis of Macrocyclic Phosphopeptidomimetics as Polo-like Kinase 1 Inhibitors, focuses on identifying compounds which might inhibit the expression of Plk1, a gene whose overexpression is often observed in tumour cells. It is being studied as a target for cancer drugs.. Instead of just synthesising different molecules and hoping they will have an impact on cancer molecules, Dominique is doing detailed computational analysis and attaching a dipeptide tail to macrocyclic compounds so that she can tell if it has any inhibiting ...
However, the rarity of the musk pods and the difficulties involved in the large-scale synthesis of macrocyclic compounds prevented their usage in perfumery and contributed to the advent of synthetic musks. Predating the identification of the macrocyclic components of natural musks of animal and plant origins, several nitromusks were synthesized serendipitously in the late 1800s (23). The nitromusks, musk ambrette, musk moskene, and musk tibetene, have long been known to be phototoxic and have been phased out of the cosmetic market. Musk ketone and musk xylene can still be used in Europe but with some restrictions because they are suspected of carcinogenic effects at high concentrations (24). With the discovery of polycyclic musks in the mid-20th century (1), synthetic musks have since enjoyed broad uses in the industry. While polycyclic musks dominate the global market, due to their lipophilic, persistent, and bioaccumulative nature, they are reported to accumulate in soil and sediments, raising ...
The present invention relates to macrocyclic compounds, methods for making these compounds, pharmaceutical compositions and the therapeutic or prophylactic use of these compounds by administering said compounds to mammals to prevent or treat hepatitis C virus (HCV) infection.
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Berninamycins B, C, and D were isolated by reverse-phased HPLC from S.bernensis. The structures of berninamycins B and D were studied with $\sp{13}$C NMR and FAB mass spectrometries. Berninamycin B was found to be deoxyberninamycin A with a valine unit instead of the $\beta$-hydroxyvaline unit of berninamycin A. Berninamycin D was found to have two less dehydroalanine units attached to the carboxyl carbon of the pyridine ring moiety. The structure of berninamycin C was postulated to have one less dehydroalanine unit attached to the carboxyl carbon of pyridine based on FABMS result. The biogeneses of these minor metabolites were discussed ...
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TY - JOUR. T1 - A novel hindered macrocyclic tetramine containing two bispidine units. A new type of proton sponge. AU - Miyahara, Yuji. AU - Goto, Kenta. AU - Inazu, Takahiko. PY - 2001/4/23. Y1 - 2001/4/23. N2 - A novel cyclam-like macrocyclic tetramine 1a was synthesized via coupling of bispidine and its bis(α-chloroacetamide) followed by reduction. Strongly basic but encrypted nitrogens of 1a were found to abstract a proton from chloroform to form dichlorocarbene.. AB - A novel cyclam-like macrocyclic tetramine 1a was synthesized via coupling of bispidine and its bis(α-chloroacetamide) followed by reduction. Strongly basic but encrypted nitrogens of 1a were found to abstract a proton from chloroform to form dichlorocarbene.. UR - http://www.scopus.com/inward/record.url?scp=0035938320&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0035938320&partnerID=8YFLogxK. U2 - 10.1016/S0040-4039(01)00341-0. DO - 10.1016/S0040-4039(01)00341-0. M3 - Article. AN - ...
In this review James C. Collins and Keith James from the Scripps Research Institute critically analyse macrocyclization reactions published over the last three years. Based upon on this analysis, and first-hand experience of macrocyclization, Collins and James propose a macrocyclization efficiency index, Emac, as a means of determining the true efficiency of a macrocyclization reaction.. Emac takes into account both reaction yield and concentration, which Collins & James state addresses the key factors that determine the practicality of using a given reaction in a drug discovery context. In other words, the Emac for a reaction indicates the likelihood of being able to conduct the reaction on a sufficiently large scale whilst remaining resource efficient.. This index also allows comparison of a large number of literature macrocyclization reactions and identifies those which deliver the powerful combination of high yield and high practicality. Collins and James hope that those who are actively ...
Methods are provided for treating humoral cancers that have been determined to be deficient in a p53-inactivating mutation in a subject. Also provided are peptidomimetic macrocycles for use in the treatment of humoral cancers that have been determined to be deficient in p53-inactivating mutations in a subject. The present invention relates to a method for treating a humoral tumor in a human subject in need of treating a humoral tumor that has been determined to lack, for example, a p53-inactivating mutation comprising the human subject Administering a pharmaceutical composition comprising a therapeutically effective amount of a peptidomimetic macrocycle or a pharmaceutically acceptable salt thereof, wherein the peptidomimetic macrocycle binds to MDM2 protein and / or MDMX protein. Provide a way.
Hemoglobin, which is the principal oxygen-carrier in humans, has four subunits in which the iron(II) ion is coordinated by the planar macrocyclic ligand protoporphyrin IX (PIX) and the imidazole nitrogen atom of a histidine residue. The sixth coordination site contains a water molecule or a dioxygen molecule. By contrast the protein myoglobin, found in muscle cells, has only one such unit. The active site is located in an hydrophobic pocket. This is important as without it the iron(II) would be irreversibly oxidized to iron(III). The equilibrium constant for the formation of HbO2 is such that oxygen is taken up or released depending on the partial pressure of oxygen in the lungs or in muscle. In hemoglobin the four subunits show a cooperativity effect that allows for easy oxygen transfer from hemoglobin to myoglobin.[10] In both hemoglobin and myoglobin it is sometimes incorrectly stated that the oxygenated species contains iron(III). It is now known that the diamagnetic nature of these species ...
0078] Complexes of manganese in the valence state II, III, IV or V which preferably comprise one or a plurality of macrocyclic ligands with the donor functions N, NR, PR, O and/or S are particularly preferably comprised. Ligands having nitrogen donor functions are preferably employed. In this regard, it is particularly preferred to incorporate bleach catalysts into the compositions according to the invention, which comprise 1,4,7-trimethyl-1,4,7-triazacyclononane (Me-TACN), 1,4,7-triazacyclononane (TACN), 1,5,9-trimethyl-1,5,9-triazacyclododecane (Me-TACD), 2-methyl-1,4,7-trimethyl-1,4,7-triazacyclononane (Me/Me-TACN) and/or 2-methyl-1,4,7-triazacyclononane (Me/TACN) as the macromolecular ligands. Suitable manganese complexes are for example [MnIII2(μ-O)1(μ-OAc)2(TACN)2](CIO4).s- ub.2, [MnIIIMnIV(μ-O)2(μ-OAc)1(TACN)2](BPh4).sub- .2, [MnIV4(μ-O)6(TACN)4](CIO4)4, [MnIII2(μ-O)1(μ-OAc)2(Me-TACN)2](CIO4- )2, [MnIIIMnIV(μ-O)1(μ-OAc)2(Me-TACN)2- ](CIO4)3, [MnIV2(μ-O)3(Me-TACN)2](PF6)2 and ...
Porphocyanines are tetrapyrrolic macrocycles containing two dipyrromethene units linked together by two C=N-C bridges. The syntheses of 2,3,7,8,14,15,19,20-octaethylporphocyanine 5,17-diphenylporphocyanine, 2,3,7,8-tetraethyl-17-phenylporphocyanine and other meso-aryl and beta-alkyl, including a tetra-beta-propionate, derivatives and metal complexes are described. The physical and chemical properties of porphocyanines show them to be aromatic. The aromaticity is reflected in the large deshielding of the outer beta-protons and shielding of the inner pyrrolic protons in their NMR spectra. The optical spectra of these compounds exhibit Soret and Q bands similar to porphyrins but all significantly bathochromically shifted. The ability of porphocyanines to act as catalysts for the generation of singlet molecular oxygen was investigated using a cholesterol oxidation assay.. ...
TY - JOUR. T1 - ANION RECEPTOR MOLECULES - SYNTHESIS AND ANION-BINDING PROPERTIES OF POLYAMMONIUM MACROCYCLES. AU - DIETRICH, B AU - HOSSEINI, M W AU - LEHN, J M AU - SESSIONS, R B PY - 1981. Y1 - 1981. M3 - Comment/debate (Academic Journal). VL - 103. SP - 1282. EP - 1283. JO - Journal of the American Chemical Society. JF - Journal of the American Chemical Society. SN - 0002-7863. IS - 5. ER - ...
Synthesis of Novel Steroid-Peptoid Hybrid Macrocycles by Multiple Multicomponent Macrocyclizations Including Bifunctional Building Blocks MiBs. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
This research project is directed towards establishing the relationship between the surface areas of intermediately sized molecules (50-300A{dollar}\sp2{dollar}) and their lateral diffusion coefficients in lipid bilayer membranes. Synthetic methods were developed to allow for the preparation of two series of macrocyclic polyamide amphiphiles, with and without fluorescent nitrobenzoxadiazole (NBD) labels, using macrocyclic polyamine aza-crown ethers as starting materials.;The geometry of the macrocyclic polyamides were determined using variable temperature NMR, which has indicated that both the C(O)-N bond and NBD-N bond in the smallest, labelled macrocyclic polyamide exhibit partial double bond character. As a consequence of this restricted bond rotation, both the amide groups and the NBD-N groups of macrocyclic polyamides can be considered as rigid planar moieties.;The surface areas occupied by the macrocyclic polyamides at the air-water interface were determined using a Langmuir film balance, and were
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p,Protein amyloid oligomers have been strongly linked to amyloid diseases and can be intermediates to amyloid fibers. β-Sheets have been identified in amyloid oligomers. However, because of their transient and highly polymorphic properties, the details of their self-association remain elusive. Here we explore oligomer structure using a model system: macrocyclic peptides. Key amyloidogenic sequences from Aβ and tau were incorporated into macrocycles, thereby restraining them to β-strands, but limiting the growth of the oligomers so they may crystallize and cannot fibrillate. We determined the atomic structures for four such oligomers, and all four reveal tetrameric interfaces in which β-sheet dimers pair together by highly complementary, dry interfaces, analogous to steric zippers found in fibers, suggesting a common structure for amyloid oligomers and fibers. In amyloid fibers, the axes of the paired sheets are either parallel or antiparallel, whereas the oligomeric interfaces display a ...
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The Katz Group explores the synthesis of complex aryl ether and aryl amine macrocycles. Our favorite targets are aza- and oxacalixarenes and related cyclophanes, generated by condensation of diphenols, diaminobenzenes, and/or aminophenols with dihalogenated aromatics. We strive for chemical and operational simplicity; the representative examples shown below are all compounds produced in either a single step (2-component macrocycles) or one-pot manner (3-component macrocycles). We continue to explore properties and applications of these and other accessible ring systems.. ...
This thesis describes work focused on the chemical synthesis and herbicidal activity of the natural product phyllostictine A, a molecule of unique structure and unknown mode of action.. Chapter 1 serves to introduce the natural product and describe the known activity of the natural product. Furthermore, it discusses literature methods for the construction of a-methylene-b-lactams, a key component of phyllostictine A.. Chapter 2 describes work towards the construction of the macrocyclic rings found in phyllostictine A. As a result a-methylene-b-lactams have been shown, for the first time, to participate in RCM reactions. Formation of 11- and 12-membered trisubstituted membered rings was possible, however, the nature of the nitrogen substituent has a large impact. For example, 12-membered rings 124, 130 were formed in 37% yield when a para-methoxyphenyl group was utilised, while simple ethyl substitution could only achieve yields of 20%. Boc protected lactam 169 produced only linear dimer 170. The ...
In a most recent accomplishment, Gladysz and his research group have made a new type of molecular rotor that shows promise for future development as a functional molecular machine capable of manipulating matter at atomic and subatomic levels and transforming multiple branches of chemistry, along with myriad related sectors and industries.. Texas A&M chemistry Ph.D. candidates Andreas Ehnbom and Sugam Kharel, postdoctoral researchers Dr. Tobias Fiedler and Dr. Hemant Joshi, and X-Ray Diffraction Laboratory assistant manager Nattamai Bhuvanesh join Gladysz as co-authors in the National Science Foundation-funded work, detailed in the cover story of this weeks edition of the Journal of the American Chemical Society.. The Gladysz group used a method called olefin metathesis recognized with the 2005 Nobel Prize in Chemistry to synthesize a series of platinum complexes with macrocyclic ring ligands that can flip over the core platinum atom in a conformation change reminiscent of Double-Dutch rope ...
The purpose of this study is to gain a better understanding of the parameters governing the synthesis of meso-substituted porphyrins. As a result of doing so, we anticipate that better reaction conditions can be developed, which will afford porphyrins in higher yields. Porphyrins are a large class of deeply colored red or purple, fluorescent crystalline pigments, of natural or synthetic origin, having in common a substituted aromatic macrocyclic ring consisting of four pyrrole-type residues, linked together by four methine bridging groups. The structure of porphyrin has been known since the early 1900s, but discrepancies exist on how the formation of porphyrin actually occurs. Several methods have been developed for the porphyrin reaction under various conditions. Three of the most common methods for the synthesis of meso-substituted porphyrins are: the Rothemund Method, the Adler Method, and the Lindsey Method. The conditions for these reactions vary from the harsh conditions where the ...
TY - JOUR. T1 - Colorimetric macrocyclic anion probes bearing nitrophenylurea and nitrophenylthiourea binding groups. AU - Aldrey, A.. AU - García, Verónica. AU - Lodeiro, C.. AU - Macías, Alejandro. AU - Pérez-Lourido, P.. AU - Valencia, Laura. AU - Bastida, Rufina. AU - Núñez, Cristina. N1 - We are grateful to the Xunta de Galicia (Spain) for the project PGIDI1OPXIB209028PR, IN845B-2010/057, and 10CSA383009PR (Biomedicine) for financial support. The authors thank the Scientific Association Proteomass (Spain) for financial support. C.N. thanks Xunta de Galicia for the I2C program postdoctoral contract.. PY - 2013/6/10. Y1 - 2013/6/10. N2 - Two novel molecular probes bearing two urea (sensor 1) or thiourea (sensor 2) groups (as anion recognition site) coupled with a nitrophenyl group (chromogenic unit) were synthesized and evaluated according to the binding site-signaling subunit approach. The behavior of these different compounds toward metal ions (Co2+, Ni2+, Cu2+, Zn 2+, and Cd2+) and ...
Technical Summary of MASTERMECTIN 10 mg/ml Solution for Injection for CATTLE, SHEEP & PIGS - C-CORP - ivermectin, macrocyclic lactone, for the control of gastrointestinal roundworms, lungworms, eyeworms, lice, mites and grubs on cattle, cows, heifers, calves, sheep, lambs, ewes, goats, swine, pigs, piglets. Indications, spectrum of activity, recommended dose, safety, toxicity, LD50, withholding period, ingredientes, composición, administration, characteristics, features.
Technical Summary of BIMECTIN PLUS Injection for CATTLE - BIMEDA - ivermectin 1% + clorsulon 10%, macrocyclic lactone, benzenesulphonamide for the control of gastrointestinal roundworms, lungworms, eyeworms, liver flukes, lice, mites and grubs on cattle, cows, heifers, calves, bulls, bovine, Indications, spectrum of activity, recommended dose, safety, toxicity, LD50, withholding period, ingredientes, composición, administration, characteristics, features.
Abstract: The study was extended to isolate the peroxo complexes of Zr (IV) containing organic acid and amine bases. The Zr (IV) complexes have been found to oxidize allyl alcohol and triphenylphosphine as well as triphenylarsine to their respective oxides. The analytical data are in good agreement with the proposed empirical formulae of the present complexes. The complexes display v(C = O) bands at ~1630 cm-1 and v(C-O) bands at ~1412 cm-1 significantly lower than the values of amino acid (~1650 and ~1450 cm-1). These indicate the coordination of amino acid through their carboxylate anion. The broad band observed at about 3217-3350 cm-1 for v (N-H) modes indicate the coordination of amino group through nitrogen atom of amino acid. The metal peroxo grouping gives rise to three IR active vibrational modes. These are predominantly O-O stretching v1, the symmetric M-O stretch v2 and the antisymmetric M-O stretch v3. The magnetic moment values indicated that these complexes were diamagnetic in ...
Chromophore Formation in Green Fluorescent Protein. B. Branchini, A. Nemser, M. Zimmer J. Am. Chem. Soc. 1998,120,1. Conformational Analysis of Cobalt(III), Copper(II), and Nickel(II) Six-Membered-Ring Systems. M.F. DaCruz, M. Zimmer Inorg. Chem. 1998, 37, 366. Site-Directed Mutagenesis of Histidine 245 in Firefly Luciferase: A proposed Model for the Active Site B. Branchini, R. Magyar, M. Murtiashaw, S. Anderson, M. Zimmer, Biochemistry 1998,37, 15311. Molecular Mechanical and Cluster Analysis of Fourteen-Membered Cobalt(III) Macrocyclic Complexes. C. Cooper, M. Zimmer.Structural Chem. 1999, 10, 17. Structural Analysis of All the nickel Fourteen-Membered Tetraaza Macrocycles in the Cambridge Structural Database. M. A. Donnelly, M. Zimmer Inorg. Chem.1999, 38, 1650. Conformational Analysis of Copper(II) 1,4,8,11,-tetraazacyclotetradecane Macrocyclic Systems M. Bakaj, M. Zimmer.J. Mol. Struct. 1999, 59, 508. Conformational Searching of Transition Metal Compounds. Jessica Bartol, ...
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