title: ortho-dihydroxyisoflavone derivatives from aged Doenjang (Korean fermented soypaste) and its radical scavenging activity.
abstract: One new ortho-dihydroxyisoflavone, 7,3',4'-trihydroxyisoflavone (2), and two known ortho-dihydroxyisoflavone derivatives were isolated from 5-year-old Doenjang (Korean fermented soypaste), and evaluated as potent antioxidant by comparing with other known isoflavones. 7,8,4'-Trihydroxyisoflavone (1), 7,3',4'-trihydroxyisoflavone (2), and 6,7,4'-trihydroxyisoflavone (3) inhibited DPPH (Diphenyl-1-picryl hydrazyl) formation by 50% at a concentration of 21.5+/-0.2, 28.7+/-0.4 and 32.6+/-0.6 (IC(50)), respectively, whereas three isoflavones showed weak DPPH radical scavenging activity. In xanthine oxidase (XO) system, in which both inhibition of xanthine oxidase and superoxide scavenging effect were measured in one assay. Compound 1 (IC(50)= 6.6+/-0.4 microM) and 2 (IC(50)=16.8+/-1.2 microM) show significant inhibitory activity and greater effect than allopurinol. But, compound 3 and other isoflavones showed lower inhibition activity. This study shows that the position of hydroxyl substituent at the aromatic ring of isoflavone plays an important role in radical scavenging effect.
authors: R&D Center, AmorePacific Corporation, Kyounggi-do 449-729, Republic of Korea. superbody@amorepacific.com
authors: Jun-Seong
authors: JS
authors: Park
authors: Hye Yoon
authors: HY
authors: Park
authors: Dong Hyun
authors: DH
authors: Kim
authors: Duck Hee
authors: DH
authors: Kim
authors: Han Kon
authors: HK
authors: Kim
mesh_terms: D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D045730:Soy Foods; D013329:Structure-Activity Relationship
chemical_list: D016166:Free Radical Scavengers; D007529:Isoflavones; C061213:3',4',7-trihydroxyisoflavone