New terpenoids from the roots of Melia azedarach

Two new terpenoids, bakayanolide (1) and 2alpha-hydroxy-3beta-methoxy-6-oxo-13alpha,14beta,17alpha-lanosta-7,24-dien-21, 16beta-olide (2), together with the known compounds 6beta-hydroxy-3-oxo-13alpha,14beta,17alpha-lanosta-7, 24-dien-21,16beta-olide (3), sendanolactone (4), kulactone (5), and beta-sitosterol have been isolated from the ethanolic root extracts of Melia azedarach. Triterpenoids (4), (5), and beta-sitosterol have been identified previously from M. azedarach, while it is the first instance of the isolation of (3) from this source. The identity of these compounds was established through extensive spectroscopic methods (infrared and mass spectroscopy, H-1 and C-13 nuclear magnetic resonance) as well as appropriate two-dimensional nuclear magnetic resonance experiments. Bakayanolide (1) belongs to the rare class of C-11 odd terpenes. Compounds (3) and (4) possessed moderate cytotoxic activity against KB cell lines.