The exploration of Neuraminidase inhibitory activity on Fallopia denticulate, an ethnic herb in China.

The present study was designed to explore the bioactive ingredients in the extract with the best neuraminidase inhibition activity of Fallopia denticulata (C.C.Huang) Holub, a folk herb medicine growing in China. Three fractions of ethyl acetate, ethanol, and water were tested on neuraminidase inhibition assay and the best one was conducted by UPLC-TOF/MS in the negative and positive mode to analyze the metabolic components. The results revealed the identification of 21 compounds: 3 organic acids, 11 flavonoids, one coumarin, and 6 others, such as β-daucosterol, gallic acid, and syringic acid. Wherein 12 compounds were discovered for the first time in F. denticulata. Besides, we utilized the molecular docking technology to support the anti- neuraminidase activity of each compound in the best extract. The results confirmed that the better two bioactive compounds were (-) -Epicatechin gallate and (+)-catechin. Therefore, F. denticulata could be the potential material of new anti-influenza drugs.