α-Glucosidase enzyme inhibitory and free radical scavenging constituents from Premna tomentosa Linn.

A bioassay-guided fractionation and chemical investigation of the whole plant of Premna tomentosa resulted in the isolation and characterization of premnalin (1), along with the known compounds coniferaldehyde (2), syrangaldehyde (3), acetoxy syrangaldehyde (4), lupeol (5), betulin (6), 2-(4-methoxyphenyl)-2-butanone (7), icetexatriene-1 (8), icetexatriene-2 (9). Their structures were established on the basis of extensive spectroscopic such as (IR, MS, 2D NMR) data analysis and by comparison with the spectroscopic data reported in the literature, premnalin (IC50: 12.11 μg/mL) & (SC50: 20.58 μg/mL), acetoxy syrangaldehyde (IC50: 18.41 μg/mL) & (SC50: 20.83 μg/mL) displayed potent α-glucosidase inhibition and free radical scavengers (DPPH).