Three minor novel triterpenoids from the leaves of Diospyros kaki

Abstract

Two novel 18, 19-secoursane triterpenoids, kakisaponin B (1) and kakisaponin C (2), an ursane type 28-nortriterpene, kakidiol (3) and one known triterpenoid rosamultin (4), were isolated from the leaves of Diospyros kaki. The structures of compounds 1 and 2 were determined as 28-O-β-D- glucopyranosyl-3α,19,24-trihydoxy-18,19-secours-11,13(18)-dien-28-oic acid (1) and 28-O-β-D-glucopyranosyl-2α,3α,19-trihydoxy-18,19- secours-11,13(18)-dien-28-oic acid (2) by chemical methods and spectra experiments. Kakidiol (3) was characterized as a C29-triterpene with an aromatic E-ring in structure. This is the first report of 18,19-secoursane triterpenoids and 28-nortriterpene from family Ebenaceae. © 2009 Pharmaceutical Society of Japan.