Novel cytotoxic ring-A seco-cycloartane triterpenes from Gardenia coronaria and G. sootepensis

Abstract

Coronalolide methyl ester (1), coronalolide (2), and coronalolic acid (3) were isolated from the leaves and/or stems of Gardenia coronaria. A further compound, methyl coronalolate acetate (4), was purified from the stems after methylation. The novel compounds 1-4 have the rare ring-A seco-cycloartane carbon skeleton and their structures were assigned on the basis of spectral data and molecular modeling, as well as X-ray crystallography performed on 1. Compounds 1 and 2 were also isolated from the leaves of Gardenia sootepensis and showed broad cytotoxic activity when evaluated against a panel of human cancer cell lines.