Study on chemical composition and α-glucosidase inhibitory activity from the leaves of Muntingia calabura

"Tr.ng ca" (Muntingia calabura) is a special species of the genus Muntingia. Phytochemical studies on the leaves of M. calabura showed that seven compounds were isolated, including R-(+)-5-( delta-tocopherol-5'-yl)-delta-tocopherol (1), trans-phytol ( 2), ergosta-4,6,8(14),22-tetraen-3-one (3), ergosterol peroxide ( 4), stigmasta-4-ene-3,6-dione (5), 6 beta hydroxystigmast-4-en-3-one (6), and ss-sitosterol (7). The structures of the compounds were elucidated by mass spectrometry, nuclear magnetic resonance spectroscopy (NMR), and compared to the literature. The biological test result for all isolated compounds showed that compounds 1-3, and 5-7 have the ability to inhibit moderately aglucosidase with IC50 values ranging from 57.9 to 249.5 mu M. Compound 3 processed a significant inhibitory activity effect with an IC50 value of 57.9 mu M, more potent than the positive control, acarbose (IC50, 214.5 mu M). This is the first time compounds 1-5 have been reported for the Muntingia genus.