Hydrolysis buffer biphasic system

Hydrolysis of glycyrrhizin in ionic liquid/buffer biphasic system [35],... 

A comparative study was made of asymmetric hydrolysis of styrene epoxide to (R)-l-phenyl-l,2-ethanediol by mung bean epoxide hydrolase in a biphasic system (n-hexane-buffer) containing hydrophilic ionic liquids (ILs). Compared to the biphasic system alone, the introduction of a small amount of hydrophilic ILs decreased the degree of non-en matic hydrolysis and increased the reaction rate by 22%. The ILs with a cation containing an alkanol group,... 

Carrier-free immobilized EHs were prepared using the cross-linked enzyme aggregate (CLEA) technology, as exemplified by the CLEA formation of a mixture of two EHs from mung beans. Compared to the free enzymes, the CLEAs exhibited significantly shorter reaction times and higher enantioconvergence for the hydrolysis of SO in a biphasic n-hexane buffer reaction system, which ensured low levels of nonenzymatic hydrolysis of the substrate [59]. 

This first chemoenzymatic synthesis [48] is not included m Fig. 1 but can be considered as a preparation of A-ring synthons in general in the steroid field, and particularly in area of vitamin D (Scheme 9). The stereo control of the quaternary chiral carbon center is one of the important subjects in asymmetrical synthesis. This issue prompted research on the use of chiral monoester 197, which can be obtained in multihundred gram scale by the pig liver esterase (PLE)-mediated hydrolysis of the corresponding symmetrical diester 196 [49]. Thus, an efficient methodology was developed for the preparation of chiral cyclohexene derivatives from cw-diester 196, using PLE in a biphasic system using phosphate buffer and acetone, to afford the chiral half-ester 197. Scheme 9 shows the efficient... 

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