Greber Katarzyna E
Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland.
J Surfactants Deterg. 2017;20(5):1189-1196. doi: 10.1007/s11743-017-2002-4. Epub 2017 Jul 31.
I studied the possibility of using amino acid-based surfactants as emulsifiers at the same time as preservatives. Fourteen lipopeptides were synthesized employing a solid phase peptide synthesis procedure. All compounds were designed to be positively charged from +1 to +4 and acylated with fatty acid chain-palmitic and miristic. The surface activity of the obtained lipopeptides was tested using a semi-automatic tensiometer to calculate parameters describing the behavior of lipopeptides in the air/water interface. Such parameters as CMC, surface tension at the CMC point (), effectiveness (), and efficiency (pC20) were measured. Emulsifying properties of all lipopeptides were also examined. The studies reveal that the surface active properties of synthesized compounds strongly depend on the length of alkyl chains as well as on the composition of amino acid polar heads. The critical micelle concentration decreases with increasing alkyl chain length of lipopeptides with the same polar head. The effectiveness and efficiency decrease when the number of amino acids in the polar head increases. All lipopeptides established a very weak emulsification power and created unstable water/Miglyol 812 and water/paraffin oil emulsions. Results suggest that lipopeptides cannot be used as emulsifiers; nonetheless, it is possible to use them as auxiliary surfactants with disinfectant properties in combination with more potent emulsifiers.
我研究了将氨基酸基表面活性剂同时用作乳化剂和防腐剂的可能性。采用固相肽合成程序合成了14种脂肽。所有化合物设计为带+1至+4的正电荷，并以脂肪酸链——棕榈酸和肉豆蔻酸进行酰化。使用半自动张力计测试所得脂肽的表面活性，以计算描述脂肽在空气/水界面行为的参数。测量了诸如临界胶束浓度（CMC）、CMC点处的表面张力（）、效能（）和效率（pC20）等参数。还研究了所有脂肽的乳化性能。研究表明，合成化合物的表面活性性质强烈取决于烷基链的长度以及氨基酸极性头部的组成。对于具有相同极性头部的脂肽，临界胶束浓度随烷基链长度的增加而降低。当极性头部中氨基酸的数量增加时，效能和效率会降低。所有脂肽的乳化能力都非常弱，形成的水/辛酸癸酸甘油三酯812乳液和水/石蜡油乳液不稳定。结果表明，脂肽不能用作乳化剂；尽管如此，将它们与更有效的乳化剂结合用作具有消毒性能的辅助表面活性剂是有可能的。
