Antioxidant constituents of radish sprout (Kaiware-daikon), Raphanus sativus L.
Methanol extracts of 11 kinds of commonly available vegetables were examined for hydroxyl radical scavenging potency using the bleomycin-Fe method. In this method, the iron ion and bleomycin in water form hydroxyl radicals, and the scavenging activity is monitored by the modified thiobarbituric acid method. All extracts showed scavenging capacity, even though the activity of some of them was lower than that of l-ascorbic acid. Those vegetables were classified into three groups according to their activity, groups showing strong activity, moderate activity, and weak activity, as compared to the activity of l-ascorbic acid at the same concentration. Among them, the methanol extract of radish sprout (Japanese name "kaiware-daikon") exhibited the highest potency (1.8 times as l-ascorbic acid). Then, we investigated the constituents of the methanol extract of radish sprout and the contribution to the overall activity of each compound by examining their activity. As the result, several kinds of sinapinic acid esters and flavonoids were isolated with high radical scavenging potency, which must contribute substantially to the activity.
Takaya
Yoshiaki
Y
Faculty of Pharmacy, Meijo University, Tempaku, Nagoya, 468-8503, Japan.
Kondo
Yoshihito
Y
Furukawa
Tadashi
T
Niwa
Masatake
M
D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D000432:Methanol; D010936:Plant Extracts / Q000737:chemistry; D031224:Raphanus / Q000737:chemistry*; D014675:Vegetables / Q000737:chemistry
D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D017665:Hydroxyl Radical; D001205:Ascorbic Acid; D000432:Methanol