Lipase Catalyzed Synthesis of D-xylose-based Biosurfactants and their Surface Properties

Synthesis of a homologous series of 1-O-acyl xylose esters with long and very long acyl chains derived from fatty acids was performed via enzymatic esterification in one step using Candida antarctica lipase B. The effect of fatty acid chain length on the activity of the lipase was evaluated. Subsequently, the surface properties of the obtained products have been determined such as hydrophilic-lipophilic balance, critical micellar concentration, and surfactant packing parameter. Foaming and emulsifying ability were also measured. The highest conversion was obtained by using docosanoic acid as an acylant agent (67.50%). The surface tension values are between 25 mN.m^-1 for 1-O-octadecanoyl-D-xylopyranose and 47,17 mN.m^-1 for 1-O-docosanoyl-D-xylopyranose. The emulsifying abilities of all esters exceeded 80%. It was found that the surface properties of the surfactants are greatly affected by the fatty acid chain length. The surface parameters results revealed that the prepared compounds have a good surface activity. Additionally, these bio-surfactants display good emulsifying ability.