ortho-dihydroxyisoflavone derivatives from aged Doenjang (Korean fermented soypaste) and its radical scavenging activity.
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.
Park
Jun-Seong
JS
R&D Center, AmorePacific Corporation, Kyounggi-do 449-729, Republic of Korea. superbody@amorepacific.com
Park
Hye Yoon
HY
Kim
Dong Hyun
DH
Kim
Duck Hee
DH
Kim
Han Kon
HK
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
D016166:Free Radical Scavengers; D007529:Isoflavones; C061213:3',4',7-trihydroxyisoflavone