Seco-terpenoids and other constituents from Elateriospermum tapos.

Two new taraxerane triterpenes, 2,3-seco-taraxer-14-ene-2,3,28-trioic acid 2,3-dimethyl ester ( 1) and 2,3-seco-taraxer-14-ene-2,3,28-trioic acid 3-methyl ester ( 2), along with two known triterpenes, hopenol B and aleuritolic acid, and five known flavonoids, putraflavone, kaempferol, sequoiaflavone, amentoflavone, and ginkgetin, were isolated from the leaves of Elateriospermum tapos. The stem extract yielded a new cleistanthane diterpene, 2,3-seco-sonderianol ( 3), three known triterpenes, lupeol, lupeol acetate, and 3-acetylaleuritolic acid, and three known diterpenes, yucalexin B-22, yucalexin P-15, and yucalexin P-17. The structures of these compounds were established on the basis of their spectroscopic data. Compound 1 was cytotoxic against NCI-H187 and BC cell lines and also showed in vitro antimycobacterial activity against Mycobacterium tuberculosis.