Comparison of phenolic compounds contained in Aquilaria leaves of different species.

Leaves of Aquilaria plants contain a variety of phenolic compounds such as iriflophenone glycosides, mangiferin, and genkwanin. Previous studies showed that Aquilaria leaf extracts exhibit many pharmacological activities, including antidiabetic and laxative effects. However, a few studies have reported differences in the chemical content and compositions of Aquilaria species. Here, three Aquilaria species were identified using matK and trnL-trnF sequences and their leaves were analyzed by HPLC and LC/MS. Comparison of the chemical components and α-glucosidase inhibition activity of the three species showed that the level of iriflophenone glycosides in A. rugosa was higher than in A. sinensis and A. crassna. There was no difference in the α-glucosidase inhibition activity of leaf extracts of the three species, but the strength of the inhibition activity can possibly be explained by the total sum of active compounds in the leaf extracts.