The Limonoids and Other Constituents from the Fruits of Melia azedarach and Their Biological Activity

Abstract

Eleven chemical constituents, including one new limonoid trichilinin G (1), were identified from the fruit extracts of M. azedarach. The structure of 1 was established by various spectroscopic and mass spectrometric analyses. Among the eleven isolated compounds, trichilinin G (1) and meliatoxin B1 (2) were examined for their antifungal activity against Fusarium oxysporum, Magnaporthe grisea, Phytophthora spp. (PS), and P. capsici (PC). Limonoid 2 showed the best antifungal activity against PS (IC50 = 103.8 μg/mL) and PC (IC50 < 62.5 μg/mL) in a dose-dependent manner. While limonoid 1 exhibited a weak to moderate activity against these Phytophthora species, F. oxysporum and M. grisea were less sensitive to the two compounds tested. The inhibitory effects of trichilinin G on superoxide anion generation and elastase release by human neutrophils were also assessed in cellular model and did not show significant activity.