基于紫外-可见光谱法研究叶黄素聚集体结构及其动力学

Studies on Structure and Dynamics of Lutein Aggregate Based on Ultraviolet-Visible Spectroscopy

利用紫外-可见分光光度计,检测了乙醇/水溶液中,不同温度下叶黄素吸收谱,并探测了光谱随时间的变化。结果表明,在1∶1乙醇/水溶液中,高浓度和低浓度样品中,叶黄素H-聚集体随温度升高呈线性降低规律。1∶2溶液中,叶黄素聚集结构不随温度变化而变化,结构稳定。对其吸收光谱的动力学检测发现,1∶1溶液中,随着时间的推移,H-聚集体呈指数增加。分析认为,溶液中水分子的氢键是形成叶黄素聚集结构的决定因素,水分子和氢键数目的增加促使叶黄素形成稳定的H-聚集结构。

The absorption spectra of lutein in ethanol/water solution at different temperat ures were measured by UV-Vis spectrophotometer and the spectral changes with time were studied.The results showed that in 1∶1 ethanol/water solution,the pro bability to form H-aggregate in two samples with different concentration(25.6 and 10.2μmol·L^-1)decreased with increasing temperature.In 1∶2 etha nol/water solution the stable aggregated structure didn’t change with temperatu re.Kinetic detection of absorption spectra of 1∶1 ethanol/water solution indic ated that the absorption of H-aggregate increased exponentially as time went by.It was concluded from analysis that the hydrogen bonds of water play an important role in the formation of aggregates.The increase of water molecules and hydrogen in ethanol/water solution leads to the formation of stable aggregated structure.