Antioxidant activities and phenolic constituents of Cephalotaxus oliveri Mast. aerial parts
The present study was to analyze the antioxidant activity and the responsible chemical constituents in Cephalotaxus oliveri Mast. aerial parts. DPPH (2,2-diphenyl-1-picryl hydrazyl), ABTS [2,2?-azinobis(3-ethylbenzothiazoline- 6-sulfonic acid)], reducing power and total phenolic content assays indicate that the methanol extract of the aerial parts is the most potent radical-scavenger and reducing agent with the highest level of phenolic content among the test extracts. The highly positive linear correlations implicate that the four assays have similar capacity to predict the antioxidant potential of the aerial parts and phenolic compounds present contribute significantly to DPPH and ABTS radical scavenging activity and reducing power of the extracts. The plant also displayed considerable superoxide anion radical scavenging activity. LC-MS/MS and GC-MS analyses resulted in the identification of 22 compounds in the methanol extract, among which are 15 phenolic compounds. The total amount of the phenolic compounds in the methanol extract determined by HPLC method was more than 5622.39 ?g/g dry weight. The considerable antioxidant potential and a high content of phenolic antioxidants suggest that C. oliveri aerial parts are a potential source of natural antioxidants.