title: New monoterpene glycosides and phenolic compounds from Distylium racemosum and their inhibitory activity against ribonuclease H.
abstract: 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 μM on HIV-2, and 1.7 μM on human RNase H, respectively.
authors.affiliation: College of Pharmacy, Chungnam National University, Daejeon 305-764, Republic of Korea.
authors.forename: Jeong Ah
authors.initials: JA
authors.lastname: Kim
authors.forename: Seo Young
authors.initials: SY
authors.lastname: Yang
authors.forename: Anthony
authors.initials: A
authors.lastname: Wamiru
authors.forename: James B
authors.initials: JB
authors.lastname: McMahon
authors.forename: Stuart F J
authors.initials: SF
authors.lastname: Le Grice
authors.forename: John A
authors.initials: JA
authors.lastname: Beutler
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Kim
mesh_terms: D004789:Enzyme Activation / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D006027:Glycosides / Q000032:analysis / Q000494:pharmacology; D015497:HIV-1 / Q000201:enzymology; D015498:HIV-2 / Q000201:enzymology; D029201:Hamamelidaceae / Q000737:chemistry*; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D039821:Monoterpenes / Q000032:analysis / Q000494:pharmacology; D010636:Phenols / Q000032:analysis / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry*; D016914:Ribonuclease H / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D006027:Glycosides; D039821:Monoterpenes; D010636:Phenols; D010936:Plant Extracts; D016914:Ribonuclease H