Cardioprotective polyphenols from Geum japonicum var. chinense.

Seven undescribed tannins, namely gejaponin A-G, and one dehydrodigallic acid derivative 3,4-dihydroxy-5-(3,4,5-trihydroxy-1-ethoxycarbonyl phenoxy)benzoic acid, together with eighteen known polyphenols were isolated from the 95% ethanol extract of the aerial part of Geum japonicum Thunb. var. chinense F. Bolle. Their structures were elucidated on the basis of comprehensive analysis of UV, IR, NMR, HRMS, and CD spectroscopy experiments. To evaluate their bioactivities, sixteen major compounds were selected to intervene in hydrogen peroxide (H 2 O 2)-induced oxidative damage on H9c2 rat cardiomyoblasts. Some compounds demonstrated high activity in this assay, of which, the known compounds 16 and 21 exhibited strong protective effects against H 2 O 2 -induced injury in H9c2 rat cardiomyoblasts, with a comparable cardioprotective activity as that of the positive control trimetazidine, thereby revealing cardioprotective activities from G. japonicum var. chinense. [Display omitted] • Eight undescribed polyphenols and eighteen known ones were purified from G. japonicum var. chinense. • The cardioprotective activities of major polyphenols were evaluated in vitro. • Coriariin B and gemin A showed high cardioprotective activity comparable to positive control TMZ. [ABSTRACT FROM AUTHOR]