Lipase-catalyzed regioselective synthesis of monoester of pyridoxine (vitamin B6) in acetonitrile

High-yield synthesis of bioactive ethyl cinnamate by enzymatic esterification of cinnamic acid

“…The yield was just 76% and 68% when a w was set at 0 and 0.86, respectively. These results seemed to be different from several previous observations (Zhang, Bai, & Sun, 2007;Zhang, Lv, & Zhi, 2011;Zhang et al, 2013) in which near-zero low a w (i.e. a w is close to 0) was in favor of those lipase-catalyzed esterification.…”

“…For instance, after 24 h of reaction, the yield was only 16% when the reaction was conducted at 10°C, while the yield reached 99% when the reaction was conducted at 50°C. These results suggested that temperature played an important role in such a reaction system, which was different from several other reactions (Zhang et al, 2007(Zhang et al, , 2011. Nevertheless, it should be point out that too high temperature would cause the loss of enzyme activity.…”

Kinetic biosynthesis of l-ascorbyl acetate by immobilized Thermomyces lanuginosus lipase (Lipozyme TLIM)

“…However, a further increase of enzyme loading to 80 mg/mL was not capable of enhancing the conversion. This observation was similar to earlier reports [3,4].…”

“…One method to avoid generating water is to use a vinyl ester as the acyl donor. Our previous result also showed that vinyl acetate as an acyl donor could increase not only the conversion, but also the regioselectivity [3]. One of the simplest methods for controlling a w was preequilibration of the reaction system in the presence of saturated salt solutions, and this method was particularly suitable for this reaction which did not generate water.…”

“…Therefore, the modification of L-ascorbic acid via esterification or transesterification with acyl donors can be used as a tool to alter solubility in oil-based formulae and emulsion. The esterification process can be either chemical or enzymatic; however, the latter is preferred because of its advantages-high catalytic efficiency, high regioselectivity, mild reaction condition and inherent selectivity of the natural catalyst [3,4].…”