Isolation and free-radical-scavenging properties of cyanidin 3-O-glycosides from the fruits of Ribes biebersteinii Berl.

The red-violet colour in fruits and vegetables is derived mainly from a class of fla-vonoids called anthocyanins. To date, more than 300 different anthocyanins have been identified in different plants. There has been an increased interest in natural anthocya-nins and anthocyanin containing plants because of their potential health promoting pro-perties and, above all, for their protection against free radicals (1). The Ribes species are known to contain high amounts of anthocyanins. Ribes biebersteinii Berl. (Grossulariaceae), commonly known as 'reddish-black berry', is an Iranian medicinal plant (2–4). The fruits of R. biebersteinii are used as food and also in the traditional medicine as a hypotensive agent and as a retina-protectant. No phytochemical or bioactivity studies on R. bieber