Dammarane triterpenes from the apical buds of Gardenia collinsae

Two new dammarane triterpenes, named 20R,24R-epoxy-3-oxo-dammarane-25ξ,26-diol (1) and its C-24 epimer (2), were isolated from the apical buds of Gardenia collinsae, along with a known compounds (20R,24R)-ocotillone (3). The structures were elucidated on the basis of spectroscopic evidence. Their cytotoxic effect on five human tumor cell lines was examined.

Two new dammarane triterpenes, named 20R,24R-epoxy-3-oxo-dammarane-25ξ,26-diol (1) and its C-24 epimer (2), were isolated from the apical buds of Gardenia collinsae, along with a known compounds (20R,24R)-ocotillone (3). The structures were elucidated on the basis of spectroscopic evidence. Their cytotoxic effect on five human tumor cell lines was examined.Highlights► Two new dammarane triterpenes, which are epimer each other at C-24 (20R,24R)- and (20R,24S)-epoxy-3-oxo-dammarane-25ξ,26-diol, were obtained from Gardenia collinsae. ► These dammaranes contain the quite unique structure due to the 25ξ,26-diol. ► Usually, triterpenes found in the plants in Gardenia family are cycloartane type. This is the first report to find the dammarane-type triterpenes from Gardenia sp. ► The compounds isolated were evaluated for their cytotoxicity on tumor cell lines and it was found that the increasing of lipophilicity at C-26 might cause the loss of activity.