Optimisation of the enantioselective biocatalytic hydrolysis of naproxen ethyl ester using ChiroCLEC-CR

Asymmetric Synthesis of N-Alkyl Amino Acids through a Biocatalytic Dynamic Kinetic Resolution of PEGylated N-Alkyl Amino Esters

The first examples of a practical procedure for a lipase-catalyzed dynamic kinetic resolution of PEGylated N-alkyl amino esters is reported. This method allows for the preparation of a broad range of aromatic and aliphatic enantiomerically enriched N-alkyl unnatural amino acids in up to 98% yield and 99% ee. We have found that PEGylated esters have a significant solubility advantage and improved reactivity over traditional hydrophobic lipase substrates, thereby allowing for efficient and scalable dynamic kinetic resolution (DKR) under aqueous conditions.

Broadening the Scope of Biocatalysis in Sustainable Organic Synthesis

This Review is aimed at synthetic organic chemists who may be familiar with organometallic catalysis but have no experience with biocatalysis, and seeks to provide an answer to the perennial question: if it is so attractive, why wasn't it extensively used in the past? The development of biocatalysis in industrial organic synthesis is traced from the middle of the last century. Advances in molecular biology in the last two decades, in particular genome sequencing, gene synthesis and directed evolution of proteins, have enabled remarkable improvements in scope and substantially reduced biocatalyst development times and cost contributions. Additionally, improvements in biocatalyst recovery and reuse have been facilitated by developments in enzyme immobilization technologies. Biocatalysis has become eminently competitive with chemocatalysis and the biocatalytic production of important pharmaceutical intermediates, such as enantiopure alcohols and amines, has become mainstream organic synthesis. The synthetic space of biocatalysis has significantly expanded and is currently being extended even further to include new-to-nature biocatalytic reactions.

The performance of immobilized Candida rugosa lipase on various surface modified graphene oxide nanosheets

In this study, we have reported the synthesis of graphene oxide nanosheets (GON) and its functionalization with 2, 4, 6-trichloro-1, 3, 5-triazine (TCT) through two routes, (a) directly reaction of GON with TCT (GON-1), and (b) reaction of GON with pre-functionalized TCT with 3-aminopropyltriethoxysilane (APTS) (GON-2). Subsequently, GON, GON-1 and GON-2 have been used as supports for immobilization of Candida rugosa lipase (CRL). Several techniques such as XRD, SEM, EDS, UV-Vis, CHNS, FTIR and AFM were applied to characterize the nano-structures and success of synthesis, functionalization and CRL immobilization processes. The results corresponding to optimization of immobilization process revealed the following order for values of loading capacity, immobilization yield and leaching of CRL: GON > GON-1 > GON-2, while this order is reversed for, specific activity and recovery activity. The assessment of operational parameters represents the high storage stability and reasonable reusability for all the immobilized CRL while the pH and thermal stability of CRL@GON-2 are higher than two others. It seems the longer linker of GON-2 could more effectively prevent the unfavorable interaction between enzyme-enzyme and enzyme-product that consequently resulted the best catalytic performance, pH and thermal stability. The advantages of these supports make them suitable candidates for practical applications.

Immobilization of Candida rugosa lipase on poly(allyl glycidyl ether-co-ethylene glycol dimethacrylate) macroporous polymer particles

Macroporous polymer particles containing surface epoxy groups were synthesized for immobilization of Candida rugosa lipase (CRL). The effect of incorporation of two different sets of monomers [allyl glycidyl ether (AGE) and glycidyl methacrylate (GMA)] and the effect of crosslinking density on immobilization of lipase were studied. AGE-co-EGDM polymers gave higher binding and expression of lipase than GMA-co-EGDM polymers. Optimization of immobilization parameters was done with respect to immobilization time and enzyme loading. Amongst AGE-co-EGDM polymer series, AGE-150 polymer found to give maximum lipase activity yield and therefore evaluated for temperature, pH and storage stability. Under optimum conditions, AGE-150 polymer gave 78.40% of activity yield. Immobilized lipase on AGE-150 showed a broader pH, higher temperature and excellent storage stability.