New monoterpene glycosides from sunflower seeds and their protective effects against H2O2-induced myocardial cell injury

Three new monoterpene glycosides (1-3) and eleven known compounds (4-14) were isolated from seeds of Helianthus annuus L. (sunflower). Their structures were determined by spectroscopic and chemical methods. All the compounds were isolated from sunflower seeds for the first time. Protective effects of compounds 1-14 against H2O2-induced H9c2 cardiomyocyte injury were evaluated, and compounds 1 and 2 showed some cell-protective effects. No significant DPPH radical scavenging activity was observed for compounds 1-14.