Tannins and Related Compounds. LXXXVII. : Isolation and Characterization of Four New Hydrolyzable Tannins from the Leaves of Mallotus repandus

Abstract

A chemical examination of the leaves of Mallotus repandus (WILLD.) MUELLER-ARG. (Euphorbiaceae) has led to the isolation of four new hydrolyzable tannins, named repandusinin (10), repandusinic acids A (11a) and B (14a) (as monopotassium salts) and mallotinin (15), together with glucogallin (1), eugeniin (2), corilagin (3), punicafolin (4), geraniin (5), furosin (6), mallotinic acid (7), mallotusinic acid (8) and brevifolin carboxylic acid (9). Based on the chemical and spectroscopic evidence, repandusinin was assigned the structure (10) in which brevifolin carboxylic acid is attached to the C-4 position of the glucose moiety in mallotinic acid, while repandusinic acids A and B were characterized as 1-O-galloyl-3, 6-(R)-hexahydroxydiphenoyl-(11a) and 1-O-galloyl-3, 6-(R)-valoneayl-4-O-(4'-dehydrochebuloyl)-β-D-glucoses (14a), respectively. Similarly, mallotinin was found to have the structure (15) possessing a new acid, mallotic acid, linked to the C-2 position of the corilagin moiety.