Characterization of Anoectochilus roxburghii Bioactive Compounds and Its Inhibition on the Metabolism-Related Enzyme Activities In Vitro

In this study, the Anoectochilus roxburghii (A. roxburghii) was studied for its chemical composition and biological activities. The first aim of this work was to isolate and purify compounds from A. roxburghii using Sephadex LH-20 and HPLC. The identification of seven compounds was achieved, with 5,4′-dihydroxy-3,3′,7-trimethoxy-flavone and 5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one being isolated from A. roxburghii for the first time. The second aim was to describe its inhibition on the metabolism-related enzyme activities in vitro. Further, 3,5-dihydroxy-7,3′,4′-trimethoxyflavone and 5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one showed inhibitory activity on xanthine oxidase, while isorhamnetin-3-O-rutinoside (IC₅₀ = 87.45 μg/mL) may be potential inhibitors of α-amylase. Molecular docking analysis revealed that isorhamnetin-3-O-rutinoside exhibited the highest binding affinity towards PL. In addition to scientifically expanding the compound library of A. roxburghii, the discovery is also a vital reference for finding new insights in the field of medication research, especially as natural metabolism-related enzyme inhibitors.