A series of maslinic acid derivatives have been synthesized by introducing various fused heterocyclic rings at C-2 and C-3 positions. Their inhibitory effects on PTP1B, TCPTP and related PTPs are evaluated. Most of the compounds exhibited a dramatic increase in inhibitory potency and selectivity, the two most potent PTP1B inhibitors 20 (IC50 = 0.61 mu M) and 29 (IC50 = 0.64 mu M) showed about 10-fold more potent than lead compound maslinic acid. More importantly, 29 possesses the best selectivity of 6.9-fold for PTP1B over TCPTP. (C) 2009 Elsevier Ltd. All rights reserved.
A series of novel substituted pyrazole-fused oleanolic acid derivative were synthesized and evaluated as selective α-glucosidase inhibitors. Among these analogs, compounds 4a–4f exhibited more potent inhibitory activities compared with their methyl ester derivatives, and standard drugs acarbose and miglitol as well. Besides, all these analogs exhibited good selectivity towards α-glucosidase over α-amylase