Comparative Study of Surface-Active Properties and Antimicrobial Activities of Disaccharide Monoesters

The objective of this research was to determine the effect of sugar or fatty acid in sugar ester compounds on the surface-active properties and antimicrobial activities of these compounds. Disaccharides of medium-chain fatty acid monoesters were synthesized through transesterifications by immobilized lipase (Lipozyme TLIM) to yield nine monoesters for subsequent study. Their antimicrobial activities were investigated using three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli O157:H7 and Candida albicans. Their surface-active properties including air–water surface tension, critical micelle concentration, and foaming and emulsion power and stability were also studied. The results showed that all of the tested monoesters were more effective against Staphylococcus aureus (Gram-positive bacterium) than against Escherichia coli O157:H7 (Gram-negative bacterium). The results demonstrated that the carbon chain length was the most important factor influencing the surface properties, whereas degree of esterification and hydrophilic groups showed little effect.

本研究旨在探究糖酯类化合物中的糖基与脂肪酸组分对其表面活性性能及抗菌活性的影响。通过固定化脂肪酶（Lipozyme TLIM）催化酯交换反应，合成了中链脂肪酸单酯二糖类产物，共获得9种单酯化合物用于后续研究。本研究选用三种病原微生物——金黄色葡萄球菌（Staphylococcus aureus）、大肠杆菌O157:H7（Escherichia coli O157:H7）以及白色念珠菌（Candida albicans），对所得单酯的抗菌活性进行了考察；同时还对其表面活性性能展开了研究，具体包括气-水界面张力、临界胶束浓度（critical micelle concentration）、发泡力、乳化力及乳化稳定性。实验结果表明，所有受试单酯对革兰氏阳性菌金黄色葡萄球菌的抑制效果均优于对革兰氏阴性菌大肠杆菌O157:H7的作用。研究结果显示，碳链长度是影响表面活性性能的最关键因素，而酯化度与亲水基团的影响则相对微弱。