Using a water-immiscible ionic liquid to improve asymmetric reduction of 4-(trimethylsilyl)-3-butyn-2-one catalyzed by immobilized Candida parapsilosis CCTCC M203011 cells

Table 1 Effect of various water-immiscible ILs on the bioreduction

Medium	Viscosity of IL (cP, 30°C)	V _o ^a (μmol/min g_cwm)	Yield^b (%)	e.e.^c (%)
Aqueous buffer	-	1.18^d	33.6^d	>99^d
C₄MIM·PF₆/buffer	173	1.56	85.0	>99
C₅MIM·PF₆/buffer	240	1.41	81.2	>99
C₆MIM·PF₆/buffer	312	1.30	77.4	>99
C₇MIM·PF₆/buffer	355	1.23	72.3	>99
iC₄MIM·PF₆/buffer	238	1.04	63.1	>99
C₂MIM·Tf₂N/buffer	25	1.21	71.6	>99
C₄MIM·Tf₂N/buffer	44	1.08	64.7	>99

Reaction conditions: 12 mM TMSB, IL/TEA-HCl buffer (100 mM, pH 5.0) volume ratio of 1/2, 98 mM 2-propanol, 0.15 g/mL cell-loaded alginate beads, 30°C, 180 r/min.
^aInitial reaction rate (V_o) is defined as the initial rate of the product formation in the total reaction system, expressed as the specific activity in μmol product per min per gram of cell wet mass (cwm) unless specified otherwise.
^bMaximum yield.
^cProduct e.e.
^dData taken from Zhang et al [10].

ISSN: 1472-6750