Three new anti-oxidative saponarin analogs from young green barley leaves

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