Phenolic antioxidants from the leaves of Corchorus olitorius L.

Six phenolic antioxidative compounds [5-caffeoylquinic acid (chlorogenic ac id), 3,5-dicaffeoylquinic acid, quercetin 3-galactoside, quercetin 3-glucos ide, quercetin 3-(6-malonylglucoside), and quercetin 3-(6-malonylgalactosid e) (tentative)] were identified from the leaves of Corchorus olitorius L. ( moroheiya) by NMR and FAB-MS. The contents of these phenolic compounds, asc orbic acid, and alpha-tocopherol in C, olitorius leaves were determined, an d their antioxidative activities were measured using the radical generator- initiated peroxidation of linoleic acid. The results obtained showed that 5 -caffeoylquinic acid was a predominant phenolic antioxidant in C. olitorius leaves.