Solvent Dependent Activity of Candida Antarctica lipase B and its Correlation with a Regioselective Mono Aza-Michael Addition- Experimental and Molecular Dynamics Simulation Studies

With the aim of gaining understanding of the molecular basis of Candida antarctica lipase B (CALB) catalyzed regioselective mono aza-Michael addition of Benzhydrazide to Diethyl maleat (DEM) we decided to carry out molecular dynamics (MD) simulation studies in parallel with our experimental study. We found a correlation between the activity of CALB and the choice of solvent. Our study showed that solvent affects the performance of the enzyme due to the binding of solvent molecules to the enzyme active site region, and the solvation energy of substrates in the different solvents. We found that CALB is only active in nonpolar solvent (i.e. Hexane), and therefore we investigated the influence of Hexane on the catalytic activity of CALB for the reaction. The results of this study and related experimental validation from our studies have been discussed here.

Synthesis, Biological Activity, and In silico Study of Bioesters Derived from Bixin by the CALB Enzyme

Biocatalysis is a branch of biotechnology that aims at the chemical transformation of a compound by using enzymes of known specificity. There are already several studies that use combinations of organic origin and enzymes as catalysts. The enzymatic sources are diverse and can be found in microorganisms, animals, vegetables, or commercial (enzymes isolated). The enzyme Candida antarctica lipase B (CALB), of microbial origin, commercially available and with high catalytic activity, can perform esterification reactions, obtaining expressive results. These biocatalytic reactions can contribute to the development of energy products, such as biofuels and pharmaceuticals, such as cosmetics and pharmaceuticals. In this context, the present project aims to esterify with the enzyme Candida antarctica lipase B (CALB), a natural product known as bixin, a dye extracted from the pericarp of annatto seeds (Bixa orellana L.) to verify its biological properties and in silico evidence of its cholesteric activity.

Enantiodivergent Synthesis of Halofuginone by Candida Antarctica Lipase B (CAL-B)-catalyzed Kinetic Resolution in Cyclopentyl Methyl Ether (CPME)

The synthesis of both enantiomers of a key intermediate in the synthesis of halofuginone was accomplished by Candida antarctica lipase B-catalyzed kinetic resolution of the corresponding racemate. When the resolution was carried out in the versatile and eco-friendly solvent cyclopentyl methyl ether (CPME) using PCPB (p-chlorophenylbutyrate) as the acylating reagent, the highest enantiomeric ratio (E) values were measured and highly enantioenriched (95% ee) compounds could be obtained in a single iteration. As an example, one of the two enantiomers was used as a starting material to prepare (+)-halofuginone in a three-step procedure.