[Limonoids from seeds of Azadirachta indica and their cytotoxic activity]

Eight limonoids were isolated from 95% ethanol extracts of neem(Azadirachta indica) seeds by various chromatographic methods. By comparison of their spectroscopic data with those reported in the literatures, these limonoids were determined as salannin(1), 1-detigloyl-1-isobutylsalannin(2), salannol-3-acetate(3), salannol(4), spirosendan(5), 1-detigloyloxy-3-deacetylsalannin-1-en-3-one(6), nimbin(7) and 6-deacetylnimbin(8). Compounds 2 and 5 were firstly isolated from this genus and 5 represented the only example of its type. And 6 is a new natural product. 6 showed inhibitory activity against HeLa and HL-60 cells, with IC₅₀ of(21.61±4.37) and(27.33±5.74) μmol·L⁻¹, respectively. Both 7 and 8 mildly inhibited the growth of HeLa cells, with IC₅₀ of (33.15±5.24) and (38.56±6.41) μmol·L⁻¹, respectively.