The merits of bipartite transition-state mimics for inhibition of uracil DNA glycosylase
作者:Yu Lin Jiang、Chunyang Cao、James T. Stivers、Fenhong Song、Yoshi Ichikawa
DOI:10.1016/j.bioorg.2004.03.001
日期:2004.8
The glycosidic bond hydrolysis reaction of the enzyme uracil DNA glycosylase (UDG) occurs by a two-step mechanism involving complete bond breakage to the uracil anion leaving group in the first step, formation of a discrete glycosyl cation-uracil anion intermediate, followed by water attack in a second transition-state leading to the enzyme-bound products of uracil and abasic DNA. We have synthesized and determined the binding affinities of unimolecular mimics of the substrate and first transition-state (TS1) in which the uracil base is covalently attached to the sugar, and in addition, bimolecular mimics of the second addition transition state (TS2) in which the base and sugar ate detached. We find that the bipartite mimics of TS2 are superior to the TS1 mimics. These results indicate that bipartite TS2 inhibitors could be useful for inhibition of glycosylases that proceed by stepwise reaction mechanisms. (C) 2004 Elsevier Inc. All rights reserved.
Synthesis of a 2-deoxy-ribose type 1-N-iminosugar
作者:Kazuishi Makino、Yoshitaka Ichikawa
DOI:10.1016/s0040-4039(98)01781-x
日期:1998.11
A 2-deoxy-ribose-type 1-N-iminosugar 5 was synthesized, in multi-gram scale, from fumaric acid monoethyl ester employing Sharpless asymmetric epoxidation followed by a Lewis acid-catalyzed (Yamammoto's aluminum reagent) cyanide epoxy ring-opening reactions.