Three New Anti-Oxidative Saponarin Analogs from Young green Barley Leaves

Abstract

Three new saponarin analogs, 6'''-sinapoylsaponarin, 6'''-feruloysaponarin and 4'-glucosyl-6'''-sinapoyl-saponarin were isolated together with four known compounds from young green barley (Hordeum vulgare var. nudum) leaves. Their anti-oxidative effects towards superoxide, photo-oxidation of vitamins and the 1, 1-diphenyl-2-picrylhydrazyl radical were tested. The superoxide-scavenging activity depended on the number of free hydroxy groups. In contrast, the inhibition of vitamin oxidation seemed to be due to the flavone skeleton. In addition, the sinapoyl moiety seemed to be important for radical-scavenging activity.