Abstract
Fractionation of the methanol extract from the roots of Salacia hainanensis Chun et How showing the potent inhibitory activity on α-glucosidase afforded two new lupane derivatives, 3α,28-dihydroxy-lup-20(29)-en-2-one (1) and 3α-hydroxy-lup-20(29)-en-2-one (2), a new friedelane derivative, D:A-friedo-oleanane-7α,30-dihydroxy-3-one (3), and a novel natural product, 2,3-seco-lup-20(29)-en-2,3-dioic acid (4), along with four known compounds (5–8). Their structures were established on the basis of spectral analysis, especially on the data afforded by 2D NMR and high-resolution mass spectra experiments. All of them showed a much stronger inhibiting activity on α-glucosidase than the positive control (acarbose, IC50 = 5.83 μM). Constituents with α-glucosidase inhibitory activity from this plant are reported for the first time.
Acknowledgements
We thank Mrs Wen Li, Mr Yi Sha and Mr Weiming Cheng of the Analytical Centers of the Shenyang Pharmaceutical University for recording NMR spectra and HR-ESI-MS. This work was supported by the National Natural Science Foundation Project of China (No. 30772717).