Studies were carried out to explore the enzymatic synthesis of glycerol and fatty acid in monolayers and microemulsions.
Monolayers of stearic acid were taken on subsolutions of glycerol and water, and the enzyme (lipozyme) solution was injected under the compressed monolayers.
Monolayers, when analyzed by TLC and HPLC, confirmed the esterification reaction. Interestingly, triglyceride and monoglyceride were the major products even though the lipozyme was I,3 specific. The same reaction was carried out in water-in-oil microemulsions with sodium di(2ethylhexyl)sulfosuccinate (AOT) as surfactant and monoglyceride and diglyceride were obtained as the major products. It was also noted that the esterification reaction in the monolayer could take place at a much higher water/glycerol ratio than in the microemulsion.
The results are explained on the basis of residence time of the product at the interface, curvature of the interface, orientation of substrate at the interface, and the interfacial activation effect on the lid of the active site of the enzyme.