Synthesis and evaluation of multisubstrate analogue inhibitors of purine nucleoside phosphorylases
作者:Tsutomu Yokomatsu、Yoshinobu Hayakawa、Taro Kihara、Satoru Koyanagi、Shinji Soeda、Hiroshi Shimeno、Shiroshi Shibuya
DOI:10.1016/s0968-0896(00)00192-9
日期:2000.11
1,1-Difluoro-2-(tetrahydro-3-furanly)ethylphosphonic acids (+/-)-cis-4a and (+/-)-trans-4a possessing a (purine-9-yl)methyl functionality at the ring as well as their homologues (+)-cis-4b and (+)-trans-4b were synthesized and tested as 'multi-substrate analogue' inhibitors for purine nucleoside phosphorylases. Radical cyclization of allylic alpha,alpha -difluorophosphonates 8a,b was applied to construct the alpha,alpha -difluorophosphonate-functionalized oxacycles 9a,b. The IC50 values of the nucleo tide analogues (+/-)-cis-4a and (+/-)-cis-4b were 88 and 38 nM, respectively, for human erythrocyte PNP-catalyzed phosphorylation of inosine in the presence of 100 mM orthophosphate. The stereochemistry of the inhibitors was found to affect significantly the inhibitory potency. The transisomers (+/-)-trans-4a and (+/-)-trans4b were ca. 4-fold less potent than the corresponding cis-isomers. At an intracellular concentration of orthophosphate (1 mM), (+/-)-cis-4b, the most potent compound of this series, was shown to have IC50 and K-i values of 8.7 and 3.5 nM, respectively. (C) 2000 Elsevier Science Ltd. All rights reserved.