Identification of flavonoids in Anoectochilus roxburghii and in vitro inhibition of key enzymes relevant to metabolic syndrome

Abstract

The traditional Chinese herb Anoectochilus roxburghii (A. roxburghii) is well-known for its medicinal value, but few studies have reported its ability to combat metabolic syndrome activities in vitro. In this study, the extraction of seven compounds from A. roxburghii using 70% ethanol, RP-C18, thin layer chromatography (TLC), Sephadex LH-20, high performance liquid chromatography (HPLC) and subsequent identification of their structures through nuclear magnetic resonance (NMR). Among these compounds, kaempferol-3-O-rutinoside and isorhamnetin-3-O-α-l-rhamnopyranoside-7-O-β-d-glucopyranoside were obtained from A. roxburghii for the first time. Results showed that those compounds inhibited key enzymes involved in metabolic syndrome in vitro. Molecular docking and binding free energy calculations were employed to elucidate the inhibition mechanism of these compounds, while SwissADME was used to assess their drug-like characteristics. Notably, 9-hydroxy-megastigma-4,7-dien-3-one-9-O-β-d-glucopyranoside has the potential as an α-amylase inhibitor for the first time. This research enriches the compound library of A. roxburghii and provides new ideas for medication research and the development of metabolic syndrome.