Abstract

The antioxidant capability, total phenol, total flavonoid, anthocyanins, ascorbic acid contents, and reducing power contents of polar and non-polar extracts for flower and leaves in two stages of growth for Rhamnus kurdica Boiss in flowering were evaluated in this work. The polar extraction of flower of R. kurdica Boiss had a higher total phenolic content as well as antioxidant activity compared to that of the other subfractions of flower and leaves in the different stages. Antioxidant activities of the samples were determined by three various testing systems namely 2, 2-diphenyl-1-picrylhydrazyl (DPPH), b-carotene/linoleic acid and reducing power assay. In DPPH system, the highest radical scavenging activity was seen by the polar subfraction in flowers of methanol extract [21.04±1.35 (µg/ml)]. Our findings demonstrate that the methanolic extracts of R. kurdica Boiss may be suggested as a new potential source of natural antioxidant.

Key word: Rhamnus kurdica Boiss, antioxidant, total phenolics, flavonoid, anthocyanins.