Carbazomarin: A New Potential of α-Glucosidase Inhibitor From Clausena excavata Roots

Continuing our exploration for dual functions antidiabetic and antioxidant agents from Myanmar medicinal plant, a new carbazole-pyranocoumarin conjugate, carbazomarin-C (1) along with a known carbazole alkaloid, mukonine (2) and a pyranocoumarin, xanthoxyletin (3), was isolated from the roots of Clausena excavata. The chemical structures of these compounds were identified using a combination of spectroscopic methods. Among isolates, there was a strong inhibition of compounds (1) and (3) on yeast α-glucosidase in a dose-dependent manner. It was shown when p-nitrophenyl-α-d-glucopyranoside was used as a substrate in vitro with IC50 values 0.22 and 4.81 mM, respectively. However, all isolated compounds displayed no inhibition against DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals.