title: Essential Structural Requirements and Additive Effects for Flavonoids to Scavenge Methylglyoxal.
abstract: Reactive dicarbonyl species, such as methylglyoxal (MGO), are considered as the major precursors of advanced glycation end products (AGEs), which are believed to be one of the physiological causes of diabetes and its complications. Scavenging of reactive dicarbonyl species using naturally occurring flavonoids has been proposed as an effective way to prevent diabetic complications. To elucidate the structural requirements of flavonoids in scavenging MGO, seven flavonoids (quercetin, luteolin, epicatechin, genistein, daidzein, apigenin, and phloretin) and five sub-components of the flavonoids (gallic acid, phloroglucinol, pyrogallol, pyrocatechol, and resorcinol) were examined in this study. Our results showed the following: (1) 1,2,3-trihydroxybenzene (pyrogallol) has higher MGO scavenging activity than 1,3,5-trihydroxybenzene and 1,2- and 1,3-dihydroxybenzene, and substitution at position 5 of pyrogallol diminished the scavenging activity, indicating that position 5 is the active site of pyrogallol; (2) the A ring is the active site of flavonoids in contributing the MGO-trapping efficacy, and the hydroxyl group at C-5 on the A ring enhances the trapping efficacy; (3) the double bond between C-2 and C-3 on the C ring could facilitate the trapping efficacy; and (4) the number of hydroxyl groups on the B ring does not significantly influence the trapping efficacy. In addition, we found there is an additive effect in MGO trapping by two common flavonoids, quercetin and phloretin, indicating that flavonoid-enriched foods and beverages hold great promise to prevent the development of diabetic complications.
authors.affiliation: Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University , North Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States.
authors.forename: Xi
authors.initials: X
authors.lastname: Shao
authors.affiliation: Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University , North Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States.
authors.forename: Huadong
authors.initials: H
authors.lastname: Chen
authors.affiliation: Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University , North Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States.
authors.forename: Yingdong
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University , North Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States.
authors.forename: Rashin
authors.initials: R
authors.lastname: Sedighi
authors.affiliation: Department of Food Science, Rutgers, The State University of New Jersey , 65 Dudley Road, New Brunswick, New Jersey 08901, United States.
authors.forename: Chi-Tang
authors.initials: CT
authors.lastname: Ho
authors.affiliation: Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University , North Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States.
authors.forename: Shengmin
authors.initials: S
authors.lastname: Sang
keywords: AGEs; MGO trapping; SAR; additive effect; flavonoids