Antitumor Agents. 169. Dysoxylum cumingianum. V. Cumingianosides P and Q, New Cytotoxic Triterpene Glucosides with an Apotirucallane-Type Skeleton from Dysoxylum cumingianum

Abstract

Detailed chemical studies on the cytotoxic fraction from the leaves of Dysoxylum cumingianum have resulted in the isolation of two new triterpene glucosides, cumingianosides P (18) and Q (19), with an apotirucallane-type skeleton. The structures of 18 and 19 were determined by spectral examinations, and by conversion of cumingianosides C (3) and A (1) into 18 and 19, respectively. The cytotoxicities of cumingianosides P and Q against over 50 human cancer cell lines were evaluated. Cumingianoside P exhibited significant (EC₅₀ <4 μM) cytotoxicity against 37 human cancer cell lines. Among them, the UO-31 (renal cancer) cell line was the most sensitive to this compound (EC₅₀ 0.267 μM). In contrast, cumingianoside Q showed selective cytotoxicity against NCI-H522 (non-small cell lung cancer) cells with an EC₅₀ value of 1.67 μM, and exhibited no cytotoxicity (EC₅₀ >10 μM) against most of the remaining cancer cell lines.