Isolation and free radical scavenging activities of a novel biflavonoid from the shells of Camellia oleifera Abel.

Oil production from the seeds of Camellia oleifera Abel. causes a great waste of shells which contain a lot of bioactive components. The aim of this research was to isolate flavonoid from the shells of C. oleifera Abel. and evaluate its uses. The shells were extracted by 70% methanol, hydrolyzed by 2 M hydrochloric acid, and further crystallized in acetone, the corresponding yield of flavonoid was up to 2.1% (purity: 93.8%). The procedure is concise, quick and proper for industrial utilization of the shells. Flavonoid was identified as bimolecular kaempferol structure by UV, MS, H-1 NMR and C-13 NMR spectra, which is a new biflavonoid and first found in C. oleifera Abel. It showed stronger scavenging activity of DPPH and ABTS radicals than kaempferol. MDA decreased, and SOD and GSH-Px activities increased significantly in serum (P<0.01) and brain tissue (P<0.05) of mice after intragastric administration of bifiavonoid at 200 mg/kg/d for 30 d. Its effects in vivo are superior to vitamin C and similar to kaempferol. Thus biflavonoid can be used as a prospective antioxidant to protect brain cells against damage from free radicals. (C) 2012 Elsevier B.V. All rights reserved.