Morusacerane: A new gammacerane triterpenoid from the trunk of Morus Alba linn. with α -glucosidase inhibitory activity.

This phytochemistry investigation on the trunk of Morus alba L. resulted in the isolation of three triterpenoids, including a new gammacerane triterpenoid - morusacerane ( 1 ); along with two known compounds of betulinic acid ( 2 ) and ursolic acid ( 3 ). The structure elucidation was thoroughly conducted based on 1D, 2D-NMR and HRESIMS spectra, followed by a comparison with existing literatures. The evaluation on α -glucosidase inhibitory exhibited the great potential of the application of these isolated compounds in diabetes treatments. The results show that morusacerane ( 1 ), betulinic acid ( 2 ), and ursolic acid ( 3 ) demonstrate the strong inhibitory with the IC ₅₀ values of 106.1, 11.12, and 7.20 μM, respectively. All of these compounds interacted well with the allosteric site enzyme α -glucosidase MAL32 through H-bonds and hydrophobic interaction.