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

Abstract

Thermomyces lanuginosus lipase (Lipozyme TLIM)-catalyzed esterification of L-ascorbic acid was studied. It was suggested that Lipozyme TLIM was a suitable biocatalyst for enzymatic esterification of L-ascorbic acid. Three solvents were investigated for the reaction, and acetone was found to be a suitable reaction medium. Furthermore, it was found that water activity could notably affect the conversion. Moreover, pH memory of Lipozyme TLIM lipase for catalyzing L-ascorbic acid esterification in acetone was observed and the effect of pH on the reaction was estimated. In addition, the influences of other parameters such as substrate mole ratio, enzyme loading, and reaction temperature and reusability of lipase on esterification of L-ascorbic acid were also analyzed systematically and quantitatively. Kinetic characterization of Lipozyme TLIM showed that K(m,a) and V(max) were 80.085 mM and 0.747 mM min(-1), respectively. As a result, Lipozyme TLIM-catalyzed esterification of L: -ascorbic acid gave a maximum conversion of 99%.

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.…”

Enzymatic Synthesis of Flavonoid Ester: Elucidation of Its Kinetic Mechanism and Equilibrium Thermodynamic Behavior

“…To circumvent the disadvantages of the conventional chemical process, enzyme-mediated catalysis in a nonaqueous medium has opened up new routes for obtaining products derived from natural antioxidants with high added value. − Lipase is preferred because of its high regioselectivity and mild reaction conditions that avoid substrate alteration. The use of enzymes makes it possible to develop a significantly simple approach for the preparation of flavonoid esters. − However, the acylation of flavonoids is limited by their solubility in organic solvents.…”

Lipase‐mediated lipid removal from propolis extract and its antiradical and antimicrobial activity

“…This result indicates that Lipozyme TL IM increases lipid esterification, which decreases fatty acid content and increases some other components, including flavonoids (Figs and ). Zhang et al reported esterification of ascorbyl acetate by immobilized Lipozyme TL IM, which is well known as an enzyme for synthesizing biodiesel via esterification . In addition, Lipozyme TL IM treatment improved the antibacterial activity toward S. epidermidis and P. acnes , which affect skin health (Fig.…”

“…This result was also observed with respect to the levels of polyphenol and flavonoid, which were reflected in the solid content. In particular, the solid content and flavonoid levels in the ethanol extraction with hexane pretreatment (HEE) group showed a fourfold increase (12.34 ± 0.09 mg mL −1 ) and a ninefold increase (457.77 ± 10.78 mg mL −1 ), respectively, compared with the levels (2.9 ± 0.14 and 51.4 ± 0.95 mg mL −1 ) in the water extraction 20 group. This result showed that HEE is a more efficient method of propolis extraction compared with other methods.…”