Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu Rd. 19, LT-50254 Kaunas, Lithuania.
Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu Rd. 19, LT-50254 Kaunas, Lithuania.
Int J Biol Macromol. 2018 Oct 15;118(Pt A):1013-1020. doi: 10.1016/j.ijbiomac.2018.06.166. Epub 2018 Jun 30.
In present study the adsorption of rosmarinic acid (RA) on chitosan (CH) powder from aqueous solution have been investigated in order to obtain insoluble RA-CH complexes with high amount of RA. The pseudo-second kinetic model and the Langmuir adsorption model described the kinetic and equilibrium adsorption of RA on CH with high correlation coefficients. With the increase of adsorption temperature the rate of adsorption decreased but amount of adsorbed RA increased. It was established that adsorption of RA on CH occurred in two steps, and relevant adsorption mechanism was proposed. The formation of RA-CH with the molar ratio of RA to CH equal to 0.11, 0.22. 0.39, 0.6 and 0.8 was investigated by FT-IR and steady-state fluorescence spectroscopic techniques. By the increase of RA amount in RA-CH complexes the character of both FT-IR and fluorescence spectra changed. The antioxidant activity of RA-CH was investigated by ABTS method and showed that RA-CH having higher amount of adsorbed RA has prolonged antioxidant activity.
在本研究中，从水溶液中研究了迷迭香酸（RA）在壳聚糖（CH）粉末上的吸附，以获得具有高含量 RA 的不溶性 RA-CH 复合物。拟二级动力学模型和 Langmuir 吸附模型描述了 RA 在 CH 上的动力学和平衡吸附，具有很高的相关性。随着吸附温度的升高，吸附速率降低，但吸附的 RA 量增加。确定 RA 在 CH 上的吸附分两步进行，并提出了相关的吸附机制。通过傅里叶变换红外光谱（FT-IR）和稳态荧光光谱技术研究了 RA 与 CH 的摩尔比分别为 0.11、0.22、0.39、0.6 和 0.8 的 RA-CH 的形成。随着 RA-CH 中 RA 量的增加，两种 FT-IR 和荧光光谱的特征均发生变化。通过 ABTS 法研究了 RA-CH 的抗氧化活性，结果表明具有较高吸附 RA 量的 RA-CH 具有延长的抗氧化活性。
