New phenolic compounds and antioxidant potential of Catharanthus roseus

8 pages, 4 figures, 1 table.
Screening of the phenolic compounds from seeds, stems, leaves and petals of Catharanthus roseus (L.) G. Don (cv. Little Bright Eye) was achieved by HPLC-DAD-ESI-MS/MS. This is the first detailed study of noncolored phenolics in C. roseus, which allowed the characterization of three caffeoylquinic acids and fifteen flavonol glycosides (di- and trisaccharides of kaempferol, quercetin and isorhamnetin). Fifteen compounds are reported for the first time in this species. The scavenging ability of the different plant matrices was assessed against DPPH• radical and against reactive oxygen (superoxide radical) and a reactive nitrogen (nitric oxide) species. A concentration-dependent protective effect was observed for seeds and tissues, with petals shown to be the most active.
D.M.P. is grateful to Fundaçäo para a Ciência e Tecnologia (PTDC/AGR-AAM/64150/2006) for the grant.