Pteridines
Xanthopterin
Neopterin
Folic Acid
Susceptibilities of Mycobacterium tuberculosis and Mycobacterium avium complex to lipophilic deazapteridine derivatives, inhibitors of dihydrofolate reductase. (1/566)
Twelve lipophilic 2,4-diamino-5-methyl-5-deazapteridine derivatives and trimethoprim were evaluated for activity against Mycobacterium tuberculosis and Mycobacterium avium in vitro. Six of the compounds had MICs of < or =12.8 mg/L and < or =1.28 mg/L against M. tuberculosis and M. avium, respectively; trimethoprim MICs were >128 mg/L and >12.8 but < or =128 mg/L, respectively. Two compounds, with either a 2-methyl-5-methoxy phenyl or 2-methoxy-5-trifluoromethyl phenyl linked at the 6-position of the deazapteridine moiety by a CH2NH bridge, had MICs of < or =0.13 mg/L against M. avium; the two compounds also had apparent I50 values for dihydrofolate reductase of 2 and 8 nM, respectively, compared with an I50 of 400 nM with trimethoprim. Four of the compounds were selectively toxic to mycobacteria as compared with Vero cells. These results demonstrated that lipophilic antifolates can be synthesized which are more active against mycobacteria than trimethoprim and which possess selective toxicity. (+info)Human molybdopterin synthase gene: identification of a bicistronic transcript with overlapping reading frames. (2/566)
A universal molybdenum-containing cofactor (MoCo) is essential for the activity of all human molybdoenzymes, including sulphite oxidase. The free cofactor is highly unstable, and all organisms share a similar biosynthetic pathway. The involved enzymes exhibit homologies, even between bacteria and humans. We have exploited these homologies to isolate a cDNA for the heterodimeric molybdopterin (MPT)-synthase. This enzyme is necessary for the conversion of an unstable precursor into molybdopterin, the organic moiety of MoCo. The corresponding transcript shows a bicistronic structure, encoding the small and large subunits of the MPT-synthase in two different open reading frames (ORFs) that overlap by 77 nucleotides. In various human tissues, only one size of mRNA coinciding with the bicistronic transcript was detected. In vitro translation and mutagenesis experiments demonstrated that each ORF is translated independently, leading to the synthesis of a 10-kDa protein and a 21-kDa protein for the small and large subunits, respectively, and indicated that the 3'-proximal ORF of the bicistronic transcript is translated by leaky scanning. (+info)Human molybdopterin synthase gene: genomic structure and mutations in molybdenum cofactor deficiency type B. (3/566)
Biosynthesis of the molybdenum cofactor (MoCo) can be divided into (1) the formation of a precursor and (2) the latter's subsequent conversion, by molybdopterin synthase, into the organic moiety of MoCo. These two steps are reflected by the complementation groups A and B and the two formally distinguished types of MoCo deficiency that have an identical phenotype. Both types of MoCo deficiency result in a pleiotropic loss of all molybdoenzyme activities and cause severe neurological damage. MOCS1 is defective in patients with group A deficiency and has been shown to encode two enzymes for early synthesis via a bicistronic transcript with two consecutive open reading frames (ORFs). MOCS2 encodes the small and large subunits of molybdopterin synthase via a single transcript with two overlapping reading frames. This gene was mapped to 5q and comprises seven exons. The coding sequence and all splice site-junction sequences were screened for mutations, in MoCo-deficient patients in whom a previous search for MOCS1 mutations had been negative. In seven of the eight patients whom we investigated, we identified MOCS2 mutations that, by their nature, are most likely responsible for the deficiency. Three different frameshift mutations were observed, with one of them found on 7 of 14 identified alleles. Furthermore, a start-codon mutation and a missense mutation of a highly conserved amino acid residue were found. The locations of the mutations confirm the functional role of both ORFs. One of the patients with identified MOCS2 mutations had been classified as type B, in complementation studies. These findings support the hypothetical mechanism, for both forms of MoCo deficiency, that formerly had been established by cell-culture experiments. (+info)Characterization of a novel unconjugated pteridine glycoside, cyanopterin, in Synechocystis sp. PCC 6803. (4/566)
A new pteridine glycoside, called cyanopterin, was isolated from Synechocystis sp. PCC 6803 and its structure was elucidated as 6-[1-(4-O-methyl-(alpha-d-glucuronyl)-(1, 6)-(beta-d-galactosyloxy]methylpterin by chemical degradation and 1H- and 13C-NMR spectroscopic means. Cyanopterin is constitutively synthesized at a relatively high intracellular concentration that is comparable to that of chlorophyll a in a molar ratio of approximately 1 to 1.6. The in vivo oxidation state of cyanopterin is primarily the fully reduced 5,6,7,8-tetrahydro form. The cellular function is unknown at present. The findings have established a model system, using Synechocystis sp. PCC 6803, for studies of the physiological functions of unconjugated pteridine glycosides found mostly in cyanobacteria. (+info)Pteridines as inhibitors of xanthine oxidase: structural requirements. (5/566)
Different pteridine derivatives were investigated for their inhibitory action on xanthine oxidase. From 27 investigated compounds, 13 showed concentration-dependent inhibition of the enzyme. Concentrations necessary for 50% inhibition ranged from <0.1 up to >100 microM. Different types of inhibition were found concerning xanthine and pterin as substrates: competitive, noncompetitive and mixed type. Out of 18 aromatic compounds tested, 12 were inhibitors. Only one out of nine reduced derivatives served as inhibitor. A simple regression model was used to specify the structural requirements for a pteridine to be an inhibitor. The most characteristic features of an inhibitor are aromaticity and no substitution at position 7 of the pteridine ring. (+info)Re-design of Rhodobacter sphaeroides dimethyl sulfoxide reductase. Enhancement of adenosine N1-oxide reductase activity. (6/566)
The periplasmic DMSO reductase from Rhodobacter sphaeroides f. sp. denitrificans has been expressed in Escherichia coli BL21(DE3) cells in its mature form and with the R. sphaeroides or E. coli N-terminal signal sequence. Whereas the R. sphaeroides signal sequence prevents formation of active enzyme, addition of a 6x His-tag at the N terminus of the mature peptide maximizes production of active enzyme and allows for affinity purification. The recombinant protein contains 1.7-1.9 guanines and greater than 0.7 molybdenum atoms per molecule and has a DMSO reductase activity of 3.4-3.7 units/nmol molybdenum, compared with 3.7 units/nmol molybdenum for enzyme purified from R. sphaeroides. The recombinant enzyme differs from the native enzyme in its color and spectrum but is indistinguishable from the native protein after redox cycling with reduced methyl viologen and Me2SO. Substitution of Cys for the molybdenum-ligating Ser-147 produced a protein with DMSO reductase activity of 1.4-1.5 units/nmol molybdenum. The mutant protein differs from wild type in its color and absorption spectrum in both the oxidized and reduced states. This substitution leads to losses of 61-99% of activity toward five substrates, but the adenosine N1-oxide reductase activity increases by over 400%. (+info)Biopterin derivatives in normal and phenylketonuric patients after oral loads of L-phenylalanine, L-tyrosine, and L-tryptophan. (7/566)
Plasma biopterin derivatives studied in 10 normal and 21 phenylketonuric children showed a significantly high concentration in the latter group. Biopterin derivatives correlated with plasma phenylalanine concentration, but in normal adults given an oral phenylalanine load the rate of increase with phenylalanine differed from that in phenylketonuric patients. A patient with hyperphenylalaninaemia, not due to phenylketonuria, had an abnormal biopterin derivatives response to phenylalanine distinct from that of patients with classical phenylketonuria. This may be a useful investigation to differentiate some variants of phenylketonuria. (+info)The strict molybdate-dependence of glucose-degradation by the thermoacidophile Sulfolobus acidocaldarius reveals the first crenarchaeotic molybdenum containing enzyme--an aldehyde oxidoreductase. (8/566)
In order to investigate the effects of trace elements on different metabolic pathways, the thermoacidophilic Crenarchaeon Sulfolobus acidocaldarius (DSM 639) has been cultivated on various carbon substrates in the presence and absence of molybdate. When grown on glucose (but neither on glutamate nor casein hydrolysate) as sole carbon source, the lack of molybdate results in serious growth inhibition. By analysing cytosolic fractions of glucose adapted cells for molybdenum containing compounds, an aldehyde oxidoreductase was detected that is present in the cytosol to at least 0.4% of the soluble protein. With Cl2Ind (2,6-dichlorophenolindophenol) as artificial electron acceptor, the enzyme exhibits oxidizing activity towards glyceraldehyde, glyceraldehyde-3-phosphate, isobutyraldehyde, formaldehyde, acetaldehyde and propionaldehyde. At its pH-optimum (6.7), close to the intracellular pH of Sulfolobus, the glyceraldehyde-oxidizing activity is predominant. The protein has an apparent molecular mass of 177 kDa and consists of three subunits of 80.5 kDa (alpha), 32 kDa (beta) and 19.5 kDa (gamma). It contains close to one Mo, four Fe, four acid-labile sulphides and four phosphates per protein molecule. Methanol extraction revealed the existence of 1 FAD per molecule and 1 molybdopterin per molecule, which was identified as molybdopterin guanine dinucleotide on the basis of perchloric acid cleavage and thin layer chromatography. EPR-spectra of the aerobically prepared enzyme exhibit the so-called 'desulpho-inhibited'-signal, known from chemically modified forms of molybdenum containing proteins. Anaerobically prepared samples show both, the signals arising from the active molybdenum-cofactor as well as from the two [2Fe-2S]-clusters. According to metal-, cofactor-, and subunit-composition, the enzyme resembles the members of the xanthine oxidase family. Nevertheless, the melting point and long-term thermostability of the protein are outstanding and perfectly in tune with the growth temperature of S. acidocaldarius (80 degrees C). The findings suggest the enzyme to function as a glyceraldehyde oxidoreductase in the course of the nonphosphorylated Entner-Doudoroff pathway and thereby may attribute a new physiological role to this class of enzyme. (+info)Pteridines are a class of heterocyclic aromatic organic compounds that are structurally related to pterins, which contain a pyrimidine ring fused to a pyrazine ring. They are naturally occurring substances that can be found in various living organisms such as bacteria, fungi, plants, and animals.
Pteridines have several important biological functions. For instance, they play a crucial role in the synthesis of folate and biotin, which are essential cofactors for various metabolic reactions in the body. Additionally, some pteridines function as chromophores, contributing to the coloration of certain organisms such as butterflies and birds.
In medicine, pteridines have been studied for their potential therapeutic applications. For example, some synthetic pteridine derivatives have shown promising results in preclinical studies as antitumor, antiviral, and antibacterial agents. However, further research is needed to fully understand the medical implications of these compounds.
Xanthopterin is not typically defined in a medical context, but it is a chemical compound that can be found in some living organisms. It's a pterin-type pigment, which means it belongs to a group of compounds that are known for their ability to impart color to various biological structures.
Xanthopterin is often found in the wings and exoskeletons of insects, contributing to their yellow or brown colors. It also has a role in the biochemistry of certain organisms, where it can function as an electron carrier in metabolic processes.
In a medical context, xanthopterin might be mentioned in relation to laboratory tests or research, particularly in fields like forensic science, where it can be used as a marker for insect activity on decomposing organic matter. However, it is not a term that would commonly appear in patient-facing medical resources or diagnoses.
Pterins are a group of naturally occurring pigments that are derived from purines. They are widely distributed in various organisms, including bacteria, fungi, and animals. In humans, pterins are primarily found in the eye, skin, and hair. Some pterins have been found to play important roles as cofactors in enzymatic reactions and as electron carriers in metabolic pathways.
Abnormal levels of certain pterins can be indicative of genetic disorders or other medical conditions. For example, an excess of biopterin, a type of pterin, is associated with phenylketonuria (PKU), a genetic disorder that affects the body's ability to metabolize the amino acid phenylalanine. Similarly, low levels of neopterin, another type of pterin, can be indicative of immune system dysfunction or certain types of cancer.
Medical professionals may measure pterin levels in blood, urine, or other bodily fluids to help diagnose and monitor these conditions.
Biopterin is a type of pteridine compound that acts as a cofactor in various biological reactions, particularly in the metabolism of amino acids such as phenylalanine and tyrosine. It plays a crucial role in the production of neurotransmitters like dopamine, serotonin, and noradrenaline. Biopterin exists in two major forms: tetrahydrobiopterin (BH4) and dihydrobiopterin (BH2). BH4 is the active form that participates in enzymatic reactions, while BH2 is an oxidized form that can be reduced back to BH4 by the action of dihydrobiopterin reductase.
Deficiencies in biopterin metabolism have been linked to several neurological disorders, including phenylketonuria (PKU), dopamine-responsive dystonia, and certain forms of autism. In these conditions, the impaired synthesis or recycling of biopterin can lead to reduced levels of neurotransmitters, causing various neurological symptoms.
Neopterin is a pteridine metabolite that is primarily produced by macrophages in response to the activation of the immune system, particularly in response to interferon-gamma (IFN-γ). It is commonly used as a biomarker for cellular immune activation and inflammation. Elevated levels of neopterin have been associated with various conditions such as infections, autoimmune diseases, cancer, and transplant rejection.
Folic acid is the synthetic form of folate, a type of B vitamin (B9). It is widely used in dietary supplements and fortified foods because it is more stable and has a longer shelf life than folate. Folate is essential for normal cell growth and metabolism, and it plays a critical role in the formation of DNA and RNA, the body's genetic material. Folic acid is also crucial during early pregnancy to prevent birth defects of the brain and spine called neural tube defects.
Medical Definition: "Folic acid is the synthetic form of folate (vitamin B9), a water-soluble vitamin involved in DNA synthesis, repair, and methylation. It is used in dietary supplementation and food fortification due to its stability and longer shelf life compared to folate. Folic acid is critical for normal cell growth, development, and red blood cell production."
Pteridine
Pteridine oxidase
Pteridine reductase
Pterin
6-Pyruvoyltetrahydropterin synthase
Biopterin
Human disease modifier gene
Catecholamines up
Sepiapterin reductase
Pterin deaminase
Lactaldehyde dehydrogenase
2,3,4-Pentanetrione
Neopterin
Eye color
Chromatophore
Nucleic acid analogue
Frilled lizard
QDPR
Pterorhodin
Biological pigment
Flavin group
PTS (gene)
Ethyl cyanoacetate
Sarcophaga peregrina
Alkylglycerol monooxygenase
Amelanism
Quinolinic acid
Tetrahydrobiopterin
Folate
3,4-Dihydroxystyrene
Pteridine - Wikipedia
4CMK: Crystal Structure Of Pteridine Reductase 1 (ptr1) From Trypanosoma Brucei In Ternary Complex With Cofactor And Inhibitor
Synthesis and properties of pteridine-2,4-dione-functionalised oligothiophenes - Enlighten Publications
Chemotherapy of malaria. Part VIII. Synthesis of uracils, thiouracils, pteridines and thiopteridines - Publications of the IAS...
where to buy Pteridines
The role of pyrimidines in the biogenesis of pteridines | Tulane University Digital Library
Planteome: Term Details for 'regulation of pteridine metabolic process' (GO:0042068)
Relationship between interferon-gamma, indoleamine 2,3-dioxygenase, and tryptophan catabolism
Thieme E-Journals - Journal of Pediatric Biochemistry / Abstract
Associate Professor Anitra Carr, Our people, University of Otago, Christchurch | University of Otago
Antioxidants | Free Full-Text | Neopterin, Inflammation, and Oxidative Stress: What Could We Be Missing?
PDB 5K6A | Chain TRYPANOSOMA BRUCEI PTERIDINE REDUCTASE 1 (PTR1) IN COMPLEX WITH COMPOUND 1 | 5K6A A | 3D Structure | canSARS
TH3WH17ERABB17- -Q- Questions. White House Insider's postings -PART- -23-, page 290
TH3WH17ERABB17- -Q- Questions. White House Insider's postings -PART- -XXV-, page 315
World Journal of Gastroenterology - Baishideng Publishing Group
XRD and DFT-modelized structures of a pteridine-2,4 (1H,3H)-dithione/N,N'- dimethylformamide H-bonded cluster (2:2). MO study...
Dr Desmond Joseph Brown MRSC
Registration Dossier - ECHA
Guide to the Human Genome
Advanced Search Results - Public Health Image Library(PHIL)
Christopher Martin
Aminopterin Summary Report | CureHunter
SCOPe 2.08: Structural Classification of Proteins - extended
Riboflavin | C17H20N4O6 | ChemSpider
Human Metabolome Database: Showing metabocard for Citicoline (HMDB0001413)
Biochem Exam 3, part 2 Flashcards
PYRAZINE Definition & Usage Examples | Dictionary.com
Zeitschrift für Naturforschung B Volume 20 Issue 4
Reductase2
- 2017). Chroman-4-one derivatives targeting pteridine reductase 1 and showing anti-parasitic activity . (up.pt)
- This gene encodes an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is important in the biosynthesis of tetrahydrobiopterin (BH4). (origene.com)
Synthesis3
- The synthesis of acceptor-functionalised oligothiophene derivatives (t3, t6, t7, t8) is described, where the pteridine-2,4-dione acceptor units are arranged symmetrically in derivatives t6-t8. (gla.ac.uk)
- A direct role for IDO in pteridine synthesis has not been shown, and this parallel induction may reflect coordinate regulation of genes induced by IFN-gamma. (nih.gov)
- Emphasis is placed on the properties of 2-thioalkyl pyrimidines as intermediates because they provide the basis for a traceless solid-state synthesis of purines, pteridines, and their analogues. (strath.ac.uk)
Fused pyrimidine1
- Pteridine is an aromatic organic compound composed of fused pyrimidine and pyrazine rings. (wikipedia.org)
Derivatives2
- The New Medicine for Trypanosomatid Infections (NMTrypI) consortium uses a highly interdisciplinary approach to optimize pteridine, benzothiazole and miltefosine derivatives, as well as natural products against Trypanosomatids. (europa.eu)
- Derivatives of the dimethylisoalloxazine (7,8-dimethylbenzo[g]pteridine-2,4(3H,10H)-dione) skeleton. (bvsalud.org)
Heterocyclic compounds1
- Pteridines also constitute a group of heterocyclic compounds containing a wide variety of substituents on this parent structure. (wikipedia.org)
Pterins1
- Pterins and flavins are classes of substituted pteridines that have diverse biological roles. (wikipedia.org)
Pathways1
- Any process that modulates the frequency, rate or extent of the chemical reactions and pathways involving pteridine. (planteome.org)
Biosynthesis1
- IDO induction has been correlated with induction of GTP-cyclohydrolase, the key enzyme in pteridine biosynthesis. (nih.gov)
Important1
- Pyrazines are components of many important compounds, including pteridines, some vitamins and antibiotics, and numerous dyes called phenazines. (dictionary.com)
Direct1
- Link to all direct and indirect annotations to regulation of pteridine metabolic process. (planteome.org)
Activity1
- If Phe is elevated, a test of erythrocyte DHPR activity and a urine pteridine profile are recommended. (nih.gov)
Chemical1
- Its chemical structure is relatively simple, consisting of a pteridine ring, para-aminobenzoic acid, and glutamic acid. (pc-mobile.net)
Reductase will not1
- In contrast to EC 1.5.1.3 and EC 1.5.1.34 , pteridine reductase will not catalyze the reduction of the quinonoid form of dihydrobiopterin. (expasy.org)
PTR11
- Pteridine reductase (PTR1) is essential for salvage of pterins by parasitic trypanosomatids and is a target for the development of improved therapies. (rcsb.org)
Neopterin2
- The detection limits of these pteridines are under 1 x 10 -10 M. The levels of neopterin, pterine, xanthopterin, and pterin-6-carboxylic acid were found to be significantly elevated in urine excreted by cancer patents, while the level of isoxanthopterin dropped in these patients. (mst.edu)
- Neopterin is a pteridine derivative that can be used as an early biomarker in various disorders such as tissue rejection, human immunodeficiency virus, multi-organ failure, sepsis, and cancer. (hacettepe.edu.tr)
Urinary3
- Pteridines' urinary concentrations seem to vary independently from each other and from normal values to yield a pattern of excreted pteridines that is diagnostic for different species, tissues, and tumor types. (hmdb.ca)
- 6. Altered urinary excretion of pteridines in neoplastic disease. (nih.gov)
- Confirmatory laboratories should have the capability to perform ion exchange chromatography (or another accepted method for measuring plasma Phe and tyrosine), erythrocyte DHPR analysis, and urinary pteridine testing (California Department of Health Services, 1997). (nih.gov)
Compounds3
- Pteridines also constitute a group of heterocyclic compounds containing a wide variety of substituents on this parent structure. (wikipedia.org)
- Pteridines are a class of compounds excreted in urine, the levels of which are found to elevate significantly in tumor-related diseases. (mst.edu)
- These are polycyclic aromatic compounds containing a pterin moiety, which consist of a pteridine ring bearing a ketone and an amine group to form 2-aminopteridin-4(3H)-one. (hmdb.ca)
Metabolism2
- Pteridines metabolism and its regulation in normal and pathological conditions have not been extensively investigated due to the difficulty of their quantification. (hmdb.ca)
- Nare, B., Hardy, L. and Beverley, S.M. The roles of pteridine reductase 1 and dihydrofolate reductase-thymidylate synthase in pteridine metabolism in the protozoan parasite Leishmania major . (enzyme-database.org)
Urine5
- Pteridine Analysis in Urine by Capillary Electrophoresis using Laser- " by Futian Han, Bryan H. Huynh et al. (mst.edu)
- For the first time, we have developed a method, based on high-performance capillary electrophoresis (HPCE) and laser-induced fluorescence (LIF) detection, to monitor the pteridine levels in urine. (mst.edu)
- Pteridine Analysis in Urine by Capillary Electrophoresis using Laser- Induced Fluorescence Detection," Analytical Chemistry , vol. 71, no. 7, pp. 1265 - 1269, American Chemical Society (ACS), Apr 1999. (mst.edu)
- Isoxanthopterin is a pteridine normally present in plasma, urine, and other bodily fluids also vary from normal concentrations in some disease states and also have diagnostic value. (hmdb.ca)
- If Phe is elevated, a test of erythrocyte DHPR activity and a urine pteridine profile are recommended. (nih.gov)
Synthesis1
- In embryos mutant for edison, yobo, yocca and brie, differences in pteridine synthesis can be observed under UV light and by thin-layer chromatography. (zfin.org)
Pigment1
- Because the fluorescence is associated with a pigment (pteridine) produced by the organism, hairs that fluorescence only at the tips is a common finding in cured cats. (tica.org)
Pyrazine1
- Pteridine is an aromatic organic compound composed of fused pyrimidine and pyrazine rings. (wikipedia.org)
Kynurenine1
- Within the scope of the thesis, it was determined that exposure to heavy metals, especially lead, in the recycling sector affects the pteridine and kynurenine pathways. (hacettepe.edu.tr)
Determination1
- Ziegler, I. The pteridine pathway in zebrafish: regulation and specification during the determination of neural crest cell-fate. (nature.com)
Biological1
- Hence, the amount of unconjugated pteridines in biological fluids has been found to be modified as a result of several disorders. (deepdyve.com)
Common1
- 5,6,7,8-Tetrahydrobiopterin (H4biopterin) is a compound related to the vitamins folic acid and riboflavin which are all characterised by the common pteridine heterocycle. (i-med.ac.at)