Tannins and related compounds. XCVIII. Structures of three new dimeric ellagitannins, excoecarianin and excoecarinins A and B, isolated from the leaves of Excoecaria kawakamii Hayata.
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.
Tannins and related compounds. XCVIII. Structures of three new dimeric ellagitannins, excoecarianin and excoecarinins A and B, isolated from the leaves of Excoecaria kawakamii Hayata.
Together with ten hydolyzable tannins and related compounds (1-10), three novel dimeric ellagitannins, excoecarianin (11), and excoecarinins A (13) and B (16), possessing a dehydrohexahydroxydiphenoyl or an elaeocarpusinoyl group, have been isolated from the leaves of Excoecaria kawakamii HAYATA (Euphorbiaceae). The structures of these tannins were established on the basis of spectroscopic and chemical evidence.
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.
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 (macaranoly group) at the 3, 6-positions of the 1C4 (or skew boat) β-D-glucopyranose ring, while macarinins A (18), B (15) and (16) were characterized as those having a tergalloyl group at the same positions.