Stilbenoids and Flavonoids from <i>Cajanus cajan</i> (L.) Millsp. and Their <i>α</i>-Glucosidase Inhibitory Activities
Yaxian Zhao,
Xinman Zhao,
Mengjia Guo,
Krishnapriya M. Varier,
Babu Gajendran,
Shaohuan Liu,
Ling Tao,
Xiangchun Shen,
Nenling Zhang
Affiliations
Yaxian Zhao
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Xinman Zhao
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Mengjia Guo
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Krishnapriya M. Varier
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Babu Gajendran
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Shaohuan Liu
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Ling Tao
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Xiangchun Shen
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Nenling Zhang
The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 550025, China
Two new stilbenoids, cajanstilbenoid C (1) and cajanstilbenoid D (2), together with eight other known stilbenoids (3-10) and seventeen known flavonoids (11-27), were isolated from the petroleum ether and ethyl acetate portions of the 95% ethanol extract of leaves of Cajanus cajan (L.) Millsp. The planar structures of the new compounds were elucidated by NMR and high-resolution mass spectrometry, and their absolute configurations were determined by comparison of their experimental and calculated electronic circular dichroism (ECD) values. All the compounds were assayed for their inhibitory activities against yeast α-glucosidase. The results demonstrated that compounds 3, 8-9, 11, 13, 19-21, and 24-26 had strong inhibitory activities against α-glucosidase, with compound 11 (IC50 = 0.87 ± 0.05 μM) exhibiting the strongest activity. The structure–activity relationships were preliminarily summarized. Moreover, enzyme kinetics showed that compound 8 was a noncompetitive inhibitor, compounds 11, 24-26 were anticompetitive, and compounds 9 and 13 were mixed-competitive.
