pH-Sensitive Surfactants from Lysine: Assessment of Their Cytotoxicity and Environmental Behavior

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• 作者：Aurora Colomer ; Aurora Pinazo ; Maria Teresa Garc铆a ; Montserrat Mitjans ; M. Pilar Vinardell ; Maria Rosa Infante ; Ver贸nica Mart铆nez ; Lourdes P茅rez
• 刊名：Langmuir
• 出版年：2012
• 出版时间：April 10, 2012
• 年：2012
• 卷：28
• 期：14
• 页码：5900-5912
• 全文大小：497K
• 年卷期：v.28,no.14(April 10, 2012)
• ISSN：1520-5827

文摘

The toxicity and environmental behavior of new pH-sensitive surfactants from lysine are presented. Three different chemical structures are studied: surfactants with one amino acid and one alkyl chain, surfactants with two amino acids on the polar head and one alkyl chain, and gemini surfactants. The pH sensitivity of these compounds can be tuned by modifying their chemical structures. Cytotoxicity has been evaluated using erythrocytes and fibroblast cells. The toxic effects against these cells depend on the hydrophobicity of the molecules as well as their cationic charge density. The effect of hydrophobicity and cationic charge density on toxicity is different for each type of cells. For erythrocytes, the toxicity increases as hydrophobicity and charge density increases. Nevertheless, for fibroblasts cationic charge density affects cytotoxicity in the opposite way: the higher charge density, the lower the toxicity. The effect of the pH on hemolysis has been evaluated in detail. The aquatic toxicity was established using Daphnia magna. All surfactants yielded EC₅₀ values considerably higher than that reported for cationic surfactants based on quaternary ammonium groups. Finally, their biodegradability was evaluated using the CO₂ headspace test (ISO 14593). These lysine derivatives showed high levels of biodegradation under aerobic conditions and can be classified as 鈥渞eadily biodegradable compounds鈥?