Microwave assisted transesterification of β-cyclodextrin

From several decades microwave assisted synthesis is known to speed up many reactions and processes. Better yield, shortening in the reaction time and easy set-up are also the one of the most important factors on this case. In opposite there is also a lot of processes known in which enzymes or whole microorganisms are inactivated by action of electromagnetic field with microwave frequencies. In some cases however it was shown that microwaves may also activate the enzymatic transformations influencing enzyme/reagent fitting or protein conformation. The phenomenon has also been observed in case of some carbohydrates. According to that in presented study enzymatic transesterification of β-cyclodextrin using vinyl esters of long chain carboxylic acids has been presented. All the reactions were performed at microwaves and in conventional conditions. Lipase from porcine pancreas was used as a biocatalyst. Reactions were carried out in DMSO or DMF as solvents using fatty acids vinyl esters as acyl donors (vinyl stearate and and vinyl laurate respectively). After the reaction the products were precipitated from the solution in several stages. Products were analyzed according to overall yield and degree of substitution. The structure of the obtained esters was investigated by means of FTIR spectroscopy. As a result the conclusion may be drowning out that microwaves induced processes by means of better yield and higher degree of substitution. The shortening in the reaction time was also observed and process looks promising as an alternative way for introducing acyl donors into carbohydrate molecules howevere further, detailed study on the transesterification should be done. The Polish State Committee supported the research for  Scientific Research Grant No. N312 331240