Fluorescence Quenching Studies of Curcumin by Hydrogen Peroxide in Acetonitrile Solution |
| |
Authors: | Email author" target="_blank">M O?IwunzeEmail author |
| |
Institution: | (1) Department of Chemistry, Morgan State University, 21251 Baltimore, Maryland, USA |
| |
Abstract: | Summary. Steady state quenching studies of curcumin, 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, fluorescence by hydrogen peroxide were conducted in acetonitrile solution. A quenching rate constant, kq, of 1.05×1010M–1·s–1 was obtained with a short fluorescence lifetime of 347ps. The reaction rate constant, which is within the diffusion-limited regime, is activation-controlled. The rate constant of deactivation of the thermally excited curcumin was 1.2 orders of magnitude more nonradiative (2.67×109s–1) than radiative (2.16×108s–1). The reaction was exothermic with a G° of –1.97eV and solvent reorganization energy of 1.37eV. These values indicate that the electron transfer reaction is solvent-mediated with electron transfer rate constant, kET, of 2.16×1010s–1. |
| |
Keywords: | , Curcumin, Antioxidant, Fluorescence, Quenching, Electron transfer, |
本文献已被 SpringerLink 等数据库收录! |
|