Antioxidant flavonoids from Tamus communis ssp cretica

A new flavonoid, kaempferol-3,4'-di-O-alpha-L-rhamnopyranoside (1), and three known flavonoids (2-4) were isolated from the aerial parts of T. communis L. The structure of the new compound was elucidated on the basis of spectroscopic data. Compounds 1 and 2 showed significant antioxidant activity (IC50 187.151 +/- 0.821 mu M, and 92.079 +/- 0.513 mu M, respectively), whereas compounds 3 and 4 showed moderate activity in DPPH free radical scavenging assays.