New Terpenoids from the Roots of Melia azedarach

Abstract

Two new terpenoids, bakayanolide (1) and 2α-hydroxy-3β-methoxy-6-oxo-13α,14β,17α-lanosta-7,24-dien-21,16β-olide (2), together with the known compounds 6β-hydroxy-3-oxo-13α,14β,17α-lanosta-7,24-dien-21,16β-olide (3), sendanolactone (4), kulactone (5), and β-sitosterol have been isolated from the ethanolic root extracts of Melia azedarach. Triterpenoids (4), (5), and β-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, ¹H and ¹³C nuclear magnetic resonance) as well as appropriate two-dimensional nuclear magnetic resonance experiments. Bakayanolide (1) belongs to the rare class of C₁₁ odd terpenes. Compounds (3) and (4) possessed moderate cytotoxic activity against KB cell lines.