Isolation and identification of antioxidants from Pedilanthus tithymaloides.

A bioassay-guided methodology utilizing 2,2-diphenyl-1-picrylhydrazyl (DPPH), the trolox equivalent antioxidant capacity (TEAC), and reducing power assays, as well as an assessment of scavenging properties against O (2) (.-) , H(2)O(2), HOCl, ROO., .NO, and ONOO(-) were used to find the main antioxidant principles of Pedilanthus tithymaloides (Euphorbiaceae), a shrub used in traditional Cuban medicine. The principles were identified as kaempferol 3-O-beta-D-glucopyranoside-6''-(3-hydroxy-3-methylglutarate), quercitrin, isoquercitrin, and scopoletin. The contents of total phenolics and flavonoids were found to be 76.0 +/- 4.8 mg of gallic acid equivalents/g extract and 9.8 +/- 0.4 mg of rutin equivalents/g extract, respectively.