RESUMEN
Four previously unreported tirucallane-type triterpenoids (1-4), together with four known analogues (5-8), were isolated from the fruits of Melia toosendan Sieb. et Zucc. Their planar structures were comprehensively elucidated by detailed analyses of HRESIMS, 1D and 2D NMR spectra data. The relative configurations of 1-4 were determined by NOESY experiments. The comparison of experimental and calculated electronic circular dichroism (ECD) spectra led to the establishment of the absolute configurations of new compounds. All isolated triterpenoids were evaluated for their α-glucosidase inhibitory activities in vitro. Compounds 4 and 5 showed moderate α-glucosidase inhibitory activities with IC50 values of 120.3 ± 5.8 and 104.9 ± 7.1 µM, respectively.