Lignans and Kauranes from the Stems of Annona cherimola

Abstract

Four lignans and six kauranes, (+)-epi-syringaresinol (1), annocherin A (16β-hydroxy-17,19-diacetoxyent-kaurane) (2), (+)-syringaresmol (3), (+)-dia-syringaresinol (4), liriodendrin[(+)-syringaresinol-di-O-β-D-glucopyranoside] (5), 16α-hydro-17-acetoxy-ent-kauran-19-oic acid (6), 16β-hydro-17-hydroxy-ent-kauran-19-al (7), 16α-hydro-17-hydroxy-ent-kauran-19-al (8), 16β-hydro-17-hydroxy-ent-kauran-19-oic acid (9) and 16α-hydro-17-hydroxy-ent-kauran-19-oic acid (10) were isolated from the stems of Annona cherimola. Among them, 1 is obtained for the first time from natural sources and 2 is a new compound. The structures of these compounds were characterized and identified by spectral analyses.