三种芦丁脂肪酸酯在空气/水界面的成膜性质

采用LB膜分析仪分别研究了芦丁硬脂酸酯(RS)、芦丁月桂酸酯(RL)和芦丁正己酸酯(RC)在空气/水界面的成膜性质,及亚相中的Al3+对3种芦丁脂肪酸酯成膜性质的影响.结果显示,3种芦丁脂肪酸酯的成膜性质与其疏水基的碳链长度、压膜速度和亚相性质有关.RS和RL能在水面铺展为液态扩张膜,RC则不能成膜.引入芦丁分子中的疏水基碳链越长,成膜越稳定.慢速压膜利于膜稳定性,膜的崩溃压大;较快速压膜能使更多膜分子保留在水表面,膜的平均分子面积大.选择适宜的压膜速度对得到比较稳定的芦丁脂肪酸酯膜很关键.当亚相中含Al3+时,RS、RL和RC均铺展成液态扩张膜,且RS膜和RL膜崩溃时的分子面积(acoll)大于它们在水表面铺展成膜的acoll.研究结果对从分子水平研究芦丁脂肪酸酯抗氧化活性的作用机制具有重要的参考价值.

Monolayers of Three Amphiphilic Esters of Rutin at the Air-Water Interface

The π-A isotherms for monolayers of three amphiphilic rutin esters,rutin-4′′′-O-stearate(RS),rutin-4′′′-O-laurate(RL) and rutin-4′′′-O-caproate(RC),were measured at the air-water interface and air-aqueous aluminum sulfate solution interface.The properties of the monolayers of three rutin esters were related to the carbon number of alkyl,the compression rate and the property of substrate.Although RS and RL showed scant water solubility,they formed monolayers with the liquid-expanded phase when spread on water.While RC could not form insoluble monolayer at the air-water interface,which may be due to the larger water solubility of RC.Appropriately low compression rate was critical to the formation of relatively stable monolayers.When spread on an aqueous aluminum sulfate solution,the formation of a complex between the aluminum ions and the rutin ester resulted in higher values of acoll for RS and RL monolayers compared with their values on water,and RC could spread as liquid-expanded phase monolayer.The present results provided valuable information for investigating the interaction of flavonoids and biomembranes and the anti-oxidant mechanism of flavonoids.