Poly[N-(2-hydroxypropyl)-11-methacryloylaminoundecanamide-co-styrene], a comb-like polymer, and its corresponding monomer was acylated with vinyl acetate, phenyl acetate, 4-fluorophenyl acetate and phenyl stearate in the presence of a lipase fromPseudomonas fluorescens [50]. The copolymer was acylated with about 40% conversion when phenyl acetate was used as the acyl donor. The higher reactivity of the monomer compared to the copolymer indicated the effect of steric hindrance on the reaction kinetics. β-Galactosidase from Aspergillus oryzae was employed as the catalyst for the functionalization of PEG with galactosylate in water using lactose as the donor [51]. 1H NMR analysis revealed 30–50% conversion. Gross and coworkers [52] prepared organosilicon carbohydrate conjugates by CALB-catalyzed regioselective esterification of siloxanes having diacid end groups with α,β-ethyl glycoside under vacuum in bulk (Fig. 10). The organosilicon reacted with the primary hydroxyl group of the α,β-ethyl glycoside; and the extent of esterification was determined by electrospray ionization mass spectrometry as 99%.