Quinone-methide triterpenes and salaspermic acid from Kokoona ochracea.

Tingenone[1],20-hydroxy-20-epi-tingenone[2],celastrol[ 3], and salaspermic acid [4] have been isolated from Kokoona ochracea stem bark. The quinone-methide triterpenes 1-3 exhibited strong but non-specific in vitro cytotoxicity against P-388 murine lymphocytic leukemia cells and a panel of human cancer cell lines. Salaspermic acid [4] was not active in all the cancer cell lines used in this investigation. 13C-nmr spectra assignments for salaspermic acid have been accomplished through the application of 1D and 2D nmr spectral techniques, and 13C-nmr assignments for celastrol [3] have been revised.