Oil Constituents from the Leaves and Stems of Drypetes hainanensis

Abstract

The present paper examines the chemical composition and antioxidant capacity of six oil fractions which were prepared by silica gel column chromatography from D. hananensis leaves and stems. Totally, 43 compounds have been identified, but 4 compounds were unidentified as well. The oil fractions investigated are characterized by a high content of saturated fatty acid, unsaturated fatty acid and bis(2-ethylhexyl)phthalate. In addition, it also contains alcohols, hydrocarbons (saturated group and alkene) and ketone. For the evaluation of the mentioned antioxidant capacities, two different methods were performed: the 2,2'-diphenyl-1-picrylhydrazyl radical scavenging method (DPPH) and ferric reducing/antioxidant power assay (FRAP). The oil fractions have a moderate antioxidant effect when tested by each method, respectively, but significant less effective than ascorbic acid and butylated hydroxytoluene. And the oil fractions are moderate to good in scavenging effect on DPPH radical but low in reducing power. The synergy among unsaturated fatty acid is suggested as possible factor, which influenced the scavenging DPPH power of the oil fractions. The unsaturated fatty acid concentrations influenced its antioxidant power, too. To our best of knowledge, this is the first report so far on the study of the content and antioxidant capacity of oil fractions from D. hainanensis leaves and stems.