Enzymatic Synthesis of Surfactants Via Amide Bonds

Abstract

Non-ionic biodegradable surfactants can be obtained by reacting amino alditol derivatives with fatty acids in the presence of lipases in organic media. Such surfactants in contrast to ester bonds, containing an amide bond are stable under alkaline conditions. The efficient coupling of N-methyl-glucamine to oleic acid can be catalysed with Lipozyme in hexane or with Novozym in 2-methyl-2-butanol as solvents. In the first case, the acid/base ratio controls both kinetics and chemo-selectivity of the reaction. In the second case, the adoption of acid base conditions allow control of the chemo-selectivity of the reaction. This reaction can also be completed by using triglycerides or fatty acid esters as acyl donors, which opens the way to the valorization of plant oils for surfactant synthesis.

Key Words:

• Surfactant
• Amide bond
• Lipase
• Organic media
• Chemo-selectivity