Tannins and Related Compounds: XCVI: Structures of Macaranins and Macarinins, New Hydrolyzable Tannins Possessing Macaranoyl and Tergalloyl Ester Groups, from the Leaves of Macaranga sinensis (Baill:) Muell.-Arg

Abstract

Together with eleven known compounds (1—11), seven new tannins, 3-desgalloylterchebin (12), macaranins A, B and C, and macarinins A, B and C, have been isolated from the leaves of Macaranga sinensis (baill.) muell.-arg. (Euphorbiaceae). Macaranins A (14), B (13) and C (17) have been determined on the basis of chemical and spectroscopic evidence to be hydrolyzable tannins possessing a novel acyl group (macaranoyl group) at the 3,6-positions of the 1C4 (or skew boat) B-D-glucopyranose ring, while macarinins A (18), B (15) and C (16) were characterized as those having a tergalloyl group at the same positions. © 1990, The Pharmaceutical Society of Japan. All rights reserved.