Masuoka Noriyoshi, Kubo Isao
a Department of Life Science , Okayama University of Science , Okayama , Japan ;
b Department of Environmental Science, Policy and Management , University of California, Berkeley , Berkeley , CA , USA.
Int J Food Sci Nutr. 2016;67(3):283-7. doi: 10.3109/09637486.2016.1153609. Epub 2016 Mar 3.
Alkyl caffeates are strong antioxidants and inhibitors of xanthine oxidase. However, it is unclear about the effect of caffeic acid and alkyl caffeates on superoxide anion (O2(-)) generation catalyzed by xanthine oxidase. Effects of caffeic acid and alkyl caffeates on the uric acid formation and O2(-) generation catalyzed by xanthine oxidase were analyzed. The scavenging activities of 1,1-diphenyl-2-picryhydrazyl (DPPH) radical and O2(-) generated with phenazine methosulfate (PMS) and NADH were examined. Caffeic acid derivatives equally suppressed O2(-) generation, and the suppression is stronger than inhibition of xanthine oxidase. Scavenging activity of O2(-) is low compared to the suppression of O2(-) generation. Suppression of O2(-) generation catalyzed by xanthine oxidase with caffeic acid derivatives was not due to enzyme inhibition or O2(-) scavenging but due to the reduction of xanthine oxidase molecules. Alkyl caffeates are effective inhibitors of uric acid and O2(-) catalyzed by xanthine oxidase as well as antioxidants for edible oil.
咖啡酸烷基酯是强抗氧化剂和黄嘌呤氧化酶抑制剂。然而，咖啡酸和咖啡酸烷基酯对黄嘌呤氧化酶催化产生超氧阴离子（O2(-)）的影响尚不清楚。分析了咖啡酸和咖啡酸烷基酯对黄嘌呤氧化酶催化尿酸形成和O2(-)产生的影响。检测了1,1-二苯基-2-苦基肼（DPPH）自由基以及用硫酸甲酯吩嗪（PMS）和烟酰胺腺嘌呤二核苷酸（NADH）产生的O2(-)的清除活性。咖啡酸衍生物同样抑制O2(-)的产生，且这种抑制作用强于对黄嘌呤氧化酶的抑制。与抑制O2(-)产生相比，O2(-)的清除活性较低。咖啡酸衍生物对黄嘌呤氧化酶催化O2(-)产生的抑制作用并非由于酶抑制或O2(-)清除，而是由于黄嘌呤氧化酶分子的减少。咖啡酸烷基酯是黄嘌呤氧化酶催化尿酸和O2(-)的有效抑制剂，也是食用油的抗氧化剂。
