A new flavanone and other constituents from the rhizomes of Polygonum amplexicaule var. sinense and their effect on osteoblastic MC3T3-E1 cells.

The phytochemical investigation of the ethyl acetate fraction of 95% ethanol extract from the rhizomes of Polygonum amplexicaule led to the isolation of thirty compounds, including a new flavanone, (2S)-6-methyl-8-isobutylenepinocembrin (1), along with ten flavonoids (2-11), three lignins (12-14), five anthraquinones (15-19), one stilbene (20), one phenylpropene (21), two chromones (23-24), five phenol derivatives (22, 27-30), aiapin (25) and β-sitosterol (26). The structural characterization of the isolated compounds was elucidated by extensive spectroscopic data and comparison with the literature. Compound 1 is the first naturally occurring flavonoid containing a C4 fragment side chain. Twelve compounds (1, 10-15, 17, 18, 20-22) were isolated for the first time from the species P. amplexicaule. Compounds 1 and 10-14 were reported from the genus Polygonum and the family Polygonaceae for the first time. The chemotaxonomic importance of these metabolites is therefore discussed. Meanwhile, we verified the effects of P. amplexicaule extracts on the proliferation, differentiation, and mineralization activity of MC3T3-E1 cells, which will also help gain a deeper understanding of the pharmacological effects of this traditional Chinese medicine in fracture repair.