RESUMO
Objective: To investigate the chemical constituents from the barks of Melia azedarach and their antidiabetes activities. Methods: The constituents were isolated and purified by silica gel, reverse phase silica gel, and Sephadex LH-20 column chromatography, and their structures were identified by spectra and physiochemical characteristic analysis. The agonist activities of the isolated triterpenoids against glucokinase (GK) and SIRT1, and the inhibitory activity against dipeptidyl peptidasesIV (DPPIV), and 11β-hydroxysteroid dehydrogenase (11β-HSD) were tested in vitro. Results: Six triterpenoids and three sterols were obtained from MeOH extract in the barks of M. azedarach and were elucidated as meliastatin 3 (1), kulonic acid (2), kulactone (3), sendanolactone (4), dubione B (5), 20, 24-cyclotirucalla-7(8)-en-16β, 21α, 25-trihydroxy-3-one (6), 3β-hydroxy-5, 8-epidioxy-ergosta-6, 22-diene (7), 2β, 3β, 4β-trihydroxy-pregn-16-one (8), and 3β-hydroxy-pregn-5, 17 (20)-dien-16-one (9). Compound 2 showed the inhibitory activity against 11β-HSD1 with the IC50 value of 54.15 nmol/L. Conclusion: Compounds 6-9 are obtained from this species for the first time. The tested compounds 1-4 are inactive against GK, SIRT1, and DPPIV, but compound 2 shows high selectivity against human 11β-HSD.