RT Journal Article
SR Electronic
T1 Inhibition of Polyphenol Oxidase by Quercetin Derivatives in Grape Skin
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP 109
OP 113
DO 10.5344/ajev.2018.17115
VO 70
IS 1
A1 Tohru Okuda
A1 Emiko Kawai
A1 Jun Harada
A1 Eri Inoue
A1 Masashi Hisamoto
A1 Fumie Watanabe-Saito
YR 2019
UL http://www.ajevonline.org/content/70/1/109.abstract
AB Polyphenol oxidase (PPO) inhibitors were isolated from grape skin and identified as quercetin derivatives. Among the inhibitors isolated, quercetin-3-glucoside (Q3Glc) was the most potent. Kinetic analysis of the inhibitory activity toward PPO was carried out with authentic Q3Glc using catechol as substrate. The inhibition was reversible, the inhibitory mechanism obtained from Lineweaver-Burk plots indicated that Q3Glc is a competitive inhibitor, and the inhibitory constant (Ki) was 84.6 µM.