A new flavanone and other constituents from the rhizomes of <i>Polygonum amplexicaule</i> 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 <i>Polygonum amplexicaule</i> led to the isolation of thirty compounds, including a new flavanone, (2<i>S</i>)-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 <i>P. amplexicaule.</i> Compounds 1 and 10-14 were reported from the genus <i>Polygonum</i> and the family Polygonaceae for the first time. The chemotaxonomic importance of these metabolites is therefore discussed. Meanwhile, we verified the effects of <i>P. amplexicaule</i> 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.