Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, USA.
J Phys Chem B. 2010 Mar 4;114(8):2997-3004. doi: 10.1021/jp9101527.
Femtosecond fluorescence upconversion experiments were performed on the naturally occurring medicinal pigment, curcumin, in anionic, cationic, and neutral micelles. In our studies, the micelles are composed of sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), and triton X-100 (TX-100). We demonstrate that the excited-state kinetics of curcumin in micelles have a fast (3-8 ps) and slow (50-80 ps) component. While deuteration of curcumin has a negligible effect on the fast component, the slow component exhibits a pronounced isotope effect of approximately 1.6, indicating that micelle-captured curcumin undergoes excited-state intramolecular hydrogen atom transfer. Studies of solvation dynamics of curcumin in a 10 ps time window reveal a fast component (< or = 300 fs) followed by a 8, 6, and 3 ps component in the solvation correlation function for the TX-100, DTAB, and SDS micelles, respectively.
飞秒荧光上转换实验在天然存在的药用色素姜黄素的阴离子、阳离子和中性胶束中进行。在我们的研究中，胶束由十二烷基硫酸钠（SDS）、十二烷基三甲基溴化铵（DTAB）和曲通 X-100（TX-100）组成。我们证明，姜黄素在胶束中的激发态动力学具有快速（3-8 ps）和慢速（50-80 ps）成分。虽然姜黄素的氘代对快速成分没有影响，但慢速成分表现出明显的同位素效应约为 1.6，表明胶束捕获的姜黄素经历了激发态分子内氢原子转移。在 10 ps 的时间窗口中对姜黄素的溶剂化动力学的研究表明，在 TX-100、DTAB 和 SDS 胶束的溶剂化相关函数中，分别存在一个快速成分（<或=300 fs），随后是一个 8、6 和 3 ps 的成分。
