Gamnamoside, a Phenylpropanoid Glycoside from Persimmon Leaves (Diospyros kaki) with an Inhibitory Effect against an Alcohol Metabolizing Enzyme

Abstract

Phytochemical investigation of the methanolic extract of Diospyros kaki leaves led to the isolation of osmanthuside H (1) and a new phenol glycoside, named gamnamoside [4-(3-hydroxypropyl)-2-methoxyphenol β-D-apiofuranosyl(1 → 6)β-D-glucopyranoside] (2) along with (-) catechin (3) through a series of reversed phase column chromatography and preparative C18 HPLC. The structures of the isolates were determined by spectroscopic methods including IR, UV, HRTOFMS, and 2D NMR. Compounds 1, 2, and 3, showed good inhibitory activities (IC50) of 175.4, 94.4, and 126.6 µg/mL respectively, whereas a reversible ADH inhibitor, 4-methylpyrazole, showed the IC50 of 326.6 µg/mL against alcohol dehydrogenase (ADH).Key Words: Persimmon, Diospyros kaki, Gamnamoside, (-) Catechin, Alcohol dehydrogenase