- Pterin–sulfa conjugates as dihydropteroate synthase inhibitors and antibacterial agents
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The sulfonamide class of antibiotics has been in continuous use for over 70?years. They are thought to act by directly inhibiting dihydropteroate synthase (DHPS), and also acting as prodrugs that sequester pterin pools by forming dead end pterin–sulfonamide conjugates. In this study, eight pterin–sulfonamide conjugates were synthesized using a novel synthetic strategy and their biochemical and microbiological properties were investigated. The conjugates were shown to competitively inhibit DHPS, and inhibition was enhanced by the presence of pyrophosphate that is crucial to catalysis and is known to promote an ordering of the DHPS active site. The co-crystal structure of Yersinia pestis DHPS bound to one of the more potent conjugates revealed a mode of binding that is similar to that of the enzymatic product analog pteroic acid. The antimicrobial activities of the pterin–sulfonamide conjugates were measured against Escherichia coli in the presence and absence of folate precursors and dependent metabolites. These results show that the conjugates have appreciable antibacterial activity and act by an on target, anti-folate pathway mechanism rather than as simple dead end products.
- Zhao, Ying,Shadrick, William R.,Wallace, Miranda J.,Wu, Yinan,Griffith, Elizabeth C.,Qi, Jianjun,Yun, Mi-Kyung,White, Stephen W.,Lee, Richard E.
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p. 3950 - 3954
(2016/08/01)
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- PYRAZINAMIDE COMPOUND
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Disclosed is a pyrazinamide compound represented by the formula (1), a tautomer, stereoisomer or pharmaceutically acceptable salt thereof, or a solvate of the compound or the tautomer, stereoisomer or pharmaceutically acceptable salt thereof, which has an excellent GK-activating activity and is therefore useful as a medicinal agent. (1) wherein R1 represents a hydrogen atom, a C1-8 alkyl group, a C3-8 cycloalkyl group, a C2-9 heterocyclyl group, a phenyl group, a C1-9 heteroaryl group, a C7-14 arylalkyl group or the like; R2 represents a C1-8 alkyl group, a C2-9 heterocyclyl group, a phenyl group, a C1-9 heteroaryl group or the like; Ar represents a monocyclic or fused polycyclic C1-9 heteroaryl group represented by the formula (2) or a C2-9 heterocyclyl group represented by formula (2); Y represents -S-, -O-or -NH-; and Z represents -S-, -O- or -CH2-.
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Page/Page column 24
(2010/04/23)
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- Mild and efficient deoxygenation of amine-N-oxides with MoCl5/NaI system
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The MoCl5/NaI system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under mild conditions. Copyright Taylor & Francis Group, LLC.
- Yoo, Byung Woo,Park, Min Chol
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p. 1646 - 1650
(2008/09/20)
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- Facile and Efficient Deoxygenation of Amine-N-oxides with Gallium in Water
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A facile and efficient procedure for the deoxygenation of amine-N-oxides with gallium metal in water is described. The experimental procedure is quite simple and the products are obtained in high yields without any activating agent.
- Han, Jung Hwa,Choi, Kyung Il,Kim, Joong Hyup,Yoo, Woo Byung
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p. 3197 - 3202
(2007/10/03)
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- Syntheses of labeled vitamers of folic acid to be used as internal standards in stable isotope dilution assays
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[2H4]Folic acid was synthesized by deuterating p-aminobenzoic acid, which was then coupled to glutamic acid and 6-formylpterin, Using [2H4]folic acid as starting component enabled the preparation of labeled vitamers tetrahydrofolate, 5-formyltetrahydrofolate, 5-methyltetrahydrofolate, and 10-formylfolate which were characterized by electrospray mass spectrometry and collision-induced dissociation. The mass spectrometric studies confirmed that the compounds could be used as internal standards in stable isotope dilution assays.
- Freisleben, Achim,Schieberle, Peter,Rychlik, Michael
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p. 4760 - 4768
(2007/10/03)
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- Synthetic Analogues of Tetrahydrobiopterin with Cofactor Activity for Aromatic Amino Acid Hydroxylases
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Tetrahydrobiopterin (THB) analogues with 6-alkoxymethyl substituents, 3a-j, where the substituents, were straight- and branched-chain alkyl ranging from methyl to octyl, have been synthesized by the Tylor method from pyrazine ortho amino nitriles by guanidine cyclization, hydrolysis in aqueous NaOH, and catalytic hydrogenation over Pt in trifluoroacetic acid (TFA).The best of these compounds, 3b, is an excellent cofactor for phenylalanine hydroxylase, tyrosine hydroxylase (V=154percent of THB), and tryptophan hydroxylase, does not destabilize the binding of substrate (Kmtyr=23 μM), and is recycled by dihydropteridine reductase (V=419percent of THB).The compounds are being evaluated as cofactor replacements in biopterin-deficiency diseases.
- Bigham, E. C.,Smith, G. K.,Reinhard, J. F.,Mallory, W. R.,Nichol, C. A.,Morrison, R. W.
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