Compositional Analyses by GC-MS and Antioxidative Activities of Senna Extracts with Different Solvents

The compositional analyses of Senna extracts with gas chromatography-mass spectrometry (GC-MS) and antioxidative activities were carried out. The leaves of Senna were extracted with petroleum ether (PE), cyclohexane, n-hexane, chloroform, ethyl acetate, acetone and methanol under ultrasound irradiation respectively to afford extracts 1 to 7 (E1 to E7). All extracts were analyzed with GC-MS. Their antioxidative activities were evaluated via DPPH radical scavenging assay and ABTS•+ radical scavenging assay. In total, 37 organic compounds (OCs) were identified including alkanes, alkenes, monoterpenoids (MTs), alcohols, phenols, aldehydes, ketones, carboxylic acids (CAs) and esters. It was showed that chloroform was the superoptimal solvent to extract various organic compounds from Senna under ultrasound irradiation. The antioxidative capacity assays showed that E7 exhibited significant scavenging activities against both DPPH and ABTS•+ radicals, E4, E5 and E6 displayed moderate DPPH and ABTS•+ radicals scavenging activity, and the antioxidative activities of E1, E2 and E3 were weak and could be neglected. The results of these investigations may contribute to the studies on the pharmcaological activity of Senna.