Efficient enzymatic modification of epigallocatechin gallate in ionic liquids

Epigallocatechin gallate (EGCG), the main polyphenolic substance in tea, exhibits well-known biological benefits. In order to improve fat solubility and bioavailability, a novel path for lipase enzymatic transesterification synthesis of acylated EGCG derivatives an ionic liquid solvent was established. The optimal reaction parameters were determined maximum conversion achieved at 98.65%. [Bmim][BF4] best medium immobilized Novozym 435 catalyst. enzyme added final concentration 2% (w/w, EGCG), performed optimum temperature 70°C stirring 10 h 250 rpm. most suitable acyl donor, vinyl acetate, mixed molar ratio 90:1 reaction. structure purified acetylated be 5″-O-acetyl-EGCG 3″, 5″-2-O-acetyl-EGCG by mass spectrometry, NMR, infrared analyses.