- Novel pyrazine compounds as transforming growth factor (TGF) compounds
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Novel pyrazine compounds, including derivatives thereof, to intermediates for their preparation, to pharmaceutical compositions containing them and to their medicinal use are described. The compounds of the present invention are potent inhibitors of trans
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- Synthesis of 3-Alkyl-6-Phenyl-4(3H)-pteridinones and their 8-Oxides. Potential Substrates of Xanthine Oxidase
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Synthetic routes for the preparation of 3-alkyl-6-phenyl-4(3H)-pteridinines 6 and their corresponding 8-oxides 5 (R=CH3, C2H5, (CH2)2CH3, (CH2)3CH3, CH(CH3)C2H5, CH(CH3)2 and CH(C2H5)CH2OCH(OC2H5)2) are described and their reactivities towards xanthine oxidase from Arthrobacter M-4 are determined.Only the 3-methyl derivative of 6-phenyl-4(3H)-pteridinone and its 8-oxide i.e. 6a and 5a are found to be substrates although their reactivities are still very low.Oxidation takes place at C-2 of the pteridinone nucleus.All the 3-alkyl derivatives are less tightly bound to t he enzyme than 6-phenyl-4(3H)-pteridinone.Introduction of the N-oxide at N-8 considerably lowers the binding of the substrates.Inhibition studies have revealed that 3-methyl-6-phenyl-4(3H)-pteridinone (6a) is non-competitive inhibitor with a Ki-value of 47 μM and the 3-ethyl derivative (6b) an uncompetitive one with a Ki-value of 19.6 μM.
- Meester, J. W. G. De,Kraus, W.,Plas, H. C. van der,Brons, H. J.,Middelhoven, W. J.
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p. 1109 - 1116
(2007/10/02)
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