Four New Depsides Isolated from Salvia miltiorrhiza and Their Significant Nerve-Protective Activities

By investigating of the roots of Salvia miltiorrhiza, which is one of the most widely used Chinese herbs, we used phytochemical methods successfully to obtain twelve depsides: four depsides (1–4) that were previously undescribed, along with eight known ones (5–12). Their structure characteristics were assessed by HR-ESIMS, CD, NMR ((1)H, (13)C, HSQC, HMBC) data analyses. These four newly isolated compounds (1–4), as well as the other eight compounds (5–12), show extraordinary protective effects on hydrogen peroxide-induced apoptosis in HS-SY5Y cells. Among them, depside 4 and depside 6 displayed more obviously protective effects than others.