Procyanidins and Phlobatannins from the Twigs of and Their Neuroprotective Activity.

Three new procyanidins (-), two new phlobatannins ( and ), a new flavan-3,4-diol glycoside (), and a new neolignan glycoside (), along with three previously reported compounds (, , and ) were isolated from the twigs of . The chemical structures of the new compounds (-, , , , and ) were characterized by spectroscopic data interpretation, including NMR (H and C NMR, H-H COSY, HSQC, HMBC, and NOESY) and HRESIMS analysis. Experimental ECD data analysis was conducted to assign the absolute configurations of the new compounds (-, , , , and ). The absolute configuration of the sugar moieties was verified through a chiral derivatization method and LC-MS analysis. All the isolated compounds (-) were evaluated for their anti-neuroinflammatory activity based on inhibitory effects on nitric oxide production using a lipopolysaccharide-stimulated murine microglia BV-2 cell line and for their neurotrophic effects on nerve growth factor induction in C6 glioma.