Five new flavonoid glycosides from Nervilia fordii

Abstract

Five new flavonoid glycosides, namely nervilifordins F–J (1–5), were isolated from the 60% EtOH extract of the aerial parts of Nervilia fordii, along with three first isolated flavonoids (7, 8, and 13) and five known flavonoids (6, 9–12). The structures of new compounds were elucidated on the basis of 1D and 2D NMR and MS studies. Their anti-inflammatory activities were tested by measuring their inhibitory effects on nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages. Compounds 2 and 5 showed interesting inhibition effects with their EC₅₀ values of 15.15 μM and 14.80 μM, respectively.

Keywords:

• Nervilia fordii
• flavonoid glycosides
• anti-inflammatory
• NO release inhibition

Acknowledgements

Financial supports of Guangxi Zhuang Autonomous Region Youth Science Foundation (grant no. 0991026), Guangxi Medical University Youth Foundation (grant no. 304203), and National Natural Science Foundation of China (grant no. 81260634) are gratefully acknowledged. The authors are grateful to Professor Hongmei Zou of Chinese Academy of Medical Sciences & Peking Union Medical College, and Dr Yinghui Duan of Institute of Traditional Chinese Medicine & Natural Products of Jinan University for their kind help in measuring HR-ESI-MS. The authors also thank Ms Y.L.Wei of Guangxi Institute of Analysis for measuring the NMR and MS data.