作者:Yanjun Zhang、David L. DeWitt、Sorimuthu Murugesan、Muraleedharan G. Nair
DOI:10.1016/j.lfs.2005.05.051
日期:2005.11
A bioassay guided phytochemical study of the ethyl acetate extract of the seeds of Picrorhiza kurroa afforded a new triterpenoid, 2 alpha, 3 beta, 19 beta, 23-tetrahydroxyolean-12-en-28-O-beta-D-glucoside (1), along with five known triterpenoids, 2 alpha, 3 beta, 19 beta, 23-tetrahydroxyolean-12-en-28-oic acid (2), 2 alpha, 3 beta, 23-trihydroxyolean-12-en-28-O-beta-D-glucoside (3), 2 alpha, 3 beta, 23-trihydroxyolean-12-en-28-oic acid (4), 2 alpha, 3 beta, 19 beta, trihydroxyolean-12-en-28-oic acid (5), and 2 alpha, 3 beta, 6 beta, 23-tetrahydroxyolean-12-en-28-oic acid (6). Their structures were established by extensive NMR spectral studies. The acetyl derivatives, compounds 7 and 8, were prepared from compounds 1 and 2, respectively, to aid in their structure elucidation. The inhibition of cyclooxygenase-2 (COX-2) enzyme by compounds 1-6 at 100 mu g/mL was 38.3%, 39%, 37%, 49.6%, 25%, and 45.0%, respectively. However, compounds 1-6, at 100 mu g/mL, did not inhibit cyclooxygenase-1 (COX-1) enzyme. Compound 1 is a novel triterpenoid and compounds 1-6 are isolated for the first time from the seeds of P kurroa. (c) 2005 Elsevier Inc. All rights reserved.