New monoterpene glycosides and phenolic compounds from Distylium racemosum and their inhibitory activity against ribonuclease H
作者:Jeong Ah Kim、Seo Young Yang、Anthony Wamiru、James B. McMahon、Stuart F.J. Le Grice、John A. Beutler、Young Ho Kim
DOI:10.1016/j.bmcl.2011.03.091
日期:2011.5
Two new monoterpene glycosides, distyloside A-B (1-2), and a new megastigmane glucoside, iso-dihydrodendranthemoside A (3) were isolated from twigs and leaves of Distylium racemosum, along with five known phenolic compounds (4-8). The structures were established via spectroscopic techniques and chemical transformations, and the absolute stereochemistry of 3 was determined by Mosher's esterification. A homogeneous fluorescence resonance energy transfer (FRET) quenching assay was used to determine the inhibitory activity of isolates (1-8) on the ribonuclease H enzymes from HIV-1, 2, human, and Escherichia coli. Among them, 6 ''-O-galloylsalidroside (6) showed potent inhibitory effects with an IC(50) value of 3.5 mu M on HIV-2, and 1.7 mu M on human RNase H, respectively. (C) 2011 Elsevier Ltd. All rights reserved.