標題: Theoretical Study for Exploring the Diglycoside Substituent Effect on the Antioxidative Capability of Isorhamnetin Extracted from Anoectochilus roxburghii
作者: Nguyen Minh Thong
Vo, Quan V.
Trinh Le Huyen
Mai Van Bay
Dinh Tuan
Pham Cam Nam
應用化學系
Department of Applied Chemistry
公開日期: 17-九月-2019
摘要: Radical-scavenging activity of isorhamnetin (1) and its diglycosides, named isorhamnetin-3,5'-O-beta-D-diglucoside (2) and isorhamnetin-3,7-O-beta-D-diglucoside (3) extracted from Anoectochilus roxburghii, has been studied through three main antioxidant pathways: hydrogen atom transfer (HAT), single electron transfer followed by proton transfer, and sequential proton loss electron transfer (SPLET). All thermodynamic parameters related to these radical-scavenging mechanisms were computed at the B3LYP/6-311G(d,p) level of theory both in the gas phase and in solution. The results suggest that HAT is the predominant mechanism in the gas phase, while SPLET is supported in an aqueous environment. In addition, the stability of radicals has also been explored by electron spin density and intramolecular hydrogen bonding. The potential energy profiles and kinetic calculations for the reactions between the selected compounds and the CH3OO center dot radical were calculated at 298.15 K. Among all investigated, compound 2 has the highest antioxidant activity with the lowest Gibbs free energy (-4.05 kcal/mol) and the highest hydrogen atom transfer rate constant (3.61 x 10(6) M(-1)s(-1)). Substitution of the OH and OMe groups by two glucoses at the 3 and 5' sites of isorhamnetin has a significant impact on its antioxidant activity.
URI: http://dx.doi.org/10.1021/acsomega.9b01780
http://hdl.handle.net/11536/153106
ISSN: 2470-1343
DOI: 10.1021/acsomega.9b01780
期刊: ACS OMEGA
Volume: 4
Issue: 12
起始頁: 14996
結束頁: 15003
顯示於類別:期刊論文