Lipase-catalyzed regioselective acylation of sugar moieties of nucleosides

Uemura, Atsuhiko; Nozaki, Kenji; Yamashita, Jun‐ichi; Yasumoto, M.

doi:10.1016/s0040-4039(01)80665-1

Cited by 50 publications

(15 citation statements)

References 7 publications

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“…from Candida rugosa and Geotrichum candidum) lose most of their activity when exposed to acetaldehyde (Weber et al, 1995). Apart from enol esters, the acylation of carbohydrates has been performed using trihaloethyl esters (Cruces et al, 1992), alkyl esters (Woudenberg et al, 1996), acid anhydrides (Uemura et al, 1989), oxime esters (Pulido and Gotor, 1992) and even free fatty acids (Ku and Hang, 1995).…”

Section: Influence Of the Acyl Donormentioning

confidence: 99%

Enzymatic acylation of di- and trisaccharides with fatty acids: choosing the appropriate enzyme, support and solvent

Plou

Cruces

Ferrer

et al. 2002

Journal of Biotechnology

183

101

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Enzymatic synthesis of fatty acid esters of di-and trisaccharides is limited by the fact that most biological catalysts are inactivated by the polar solvents (e.g. dimethylsulfoxide, dimethylformamide) where these carbohydrates are soluble. This article reviews the methodologies developed to overcome this limitation, namely those involving control over the reaction medium, the enzyme and the support. We have proposed the use of mixtures of miscible solvents (e.g. dimethylsulfoxide and 2-methyl-2-butanol) as a general strategy to acylate enzymatically hydrophilic substrates.We observed that decreasing the hydrophobicity of the medium (i.e. lowering the percentage of DMSO) the molar ratio sucrose diesters vs. sucrose monoesters can be substantially enhanced. The different regioselectivity exhibited by several lipases and proteases makes feasible to synthesize different positional isomers, whose properties may vary considerably. In particular, the lipase from Thermomyces lanuginosus displays a notable selectivity for only one hydroxyl group in the acylation of sucrose, maltose, leucrose and maltotriose, compared with lipase from Candida antarctica. We have examined three immobilisation methods (adsorption on polypropylene, covalent coupling to Eupergit C, and silica-granulation) for sucrose acylation catalyzed by T. lanuginosus lipase. The morphology of the support affected significantly the reaction rate and/or the selectivity of the process.

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Section: Influence Of the Acyl Donormentioning

confidence: 99%

Enzymatic acylation of di- and trisaccharides with fatty acids: choosing the appropriate enzyme, support and solvent

Plou

Cruces

Ferrer

et al. 2002

Journal of Biotechnology

183

101

View full text Add to dashboard Cite

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“…Organic reaction media may facilitate the use of unusual water-labile substrates such as acid anhydrides which are suitable irreversible acyl transfer agents for many lipases but which are rapidly destroyed by water. Acid anhydrides have been used for lipase mediated acylation of nucleosides in DMSO, DMF, or DMA [68], and a range of alcohols in diethyl ether [69] or benzene containing a very low water content [70].…”

Section: Which Have Been Utilised For the Synthesis Of Many Hydrophobmentioning

confidence: 99%

Biocatalysis in Organic Media

Cowan

Plant²

1992

ACS Symposium Series

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It is now accepted that organic media are widely applicable to biocatalytic processes. Enzyme reactions have been demonstrated in many different solvent systems containing apolar solvents with a wide range of hydrophobicities. In such systems the aqueous fraction of the solvent may vary from trace levels (the "microaqueous" reaction system) to the major constituent.The properties of enzymes in media containing both aqueous and apolar constituents are influenced by many factors including the dielectric constant, the concentration or "activity" of water, the presence of phase-interfaces, etc. All of these factors influence the structural stability of the enzyme to some degree and optimization of enzymestability in response to these factors is of critical importance in the design of any organic-solvent biocatalytic system.The presence of apolar solvents, even at low concentrations, may influence protein structure at a more subtle level, resulting in significant changes in reaction kinetics, substrate specificity and stereoselectivity. Thus "solvent engineering" can be used to exert control over reaction mechanisms, product spectrum and yield In order to take full advantage of the effects of different solvents on enzyme function in designing reaction systems, an understanding of the molecular interactions between solvent and protein is essential. For example, a detailed knowledge of the role of protein solvation shell water and the distortion of this shell by hydrophilic organic solvents may assist in the design of "solvent resistant" enzymes. Similarly, the inferred influence of low water content solvents on conformational mobility may permit us to select solvent systems which will optimise the chemical and optical purity of the reaction products. Organic Phase Reaction SystemsIntroduction. Numerous factors are important in defining the physical and chemical effects of any aqueous-organic solvent system on constituent proteins. Nevertheless, in order to optimise or indeed establish a viable organic phase biocatalytic system, it is important to be aware of the manner in which these factors impinge on biocatalyst structure and function. Single properties such as organic phase hydrophobicity and

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“…The enzymatic process being reversible requires a long reaction time and a large excess of the esters as acyl donors in order to achieve a reasonable degree of conversion (1, 2). Therefore, various activated esters such as trifluoroethyl esters, chloroethyl esters (3), and acid anhydrides (4, 5) have been reported, to make the enzymatic transesterification process kinetically irreversible. However, this method was also not free from the drawbacks, such as the generation of toxic side products, which led to the deactivation of the lipases (6).…”

Section: Introductionmentioning

confidence: 99%

Effect of Reaction Parameters on Synthesis of Citronellyl Methacrylate by Lipase‐Catalyzed Transesterification

Athawale

Manjrekar

Athawale

2003

Biotechnology Progress

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The methacrylate ester of citronellol was synthesized using various lipases as catalyst. The effect of different reaction parameters such as amount of lipase, solvent, temperature, and acylating agent on the conversion of citronellol to citronellyl methacrylate was studied. Methyl methacrylate, vinyl methacrylate, and 2,3-butanedione mono-oxime methacrylate were used as acylating agents. Porcine pancreatic lipase (PPL), Candida rugosa lipase (CRL), and Pseudomonas cepacia lipase (Amano-PS) were used as biocatalysts. Diisopropyl ether (DIPE) was found to be the most suitable solvent. The stereoselectivity of CRL in transesterification of (+/-)-citronellol was tested for the optimized reaction parameters.

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Lipase-catalyzed regioselective acylation of sugar moieties of nucleosides

Cited by 50 publications

References 7 publications

Enzymatic acylation of di- and trisaccharides with fatty acids: choosing the appropriate enzyme, support and solvent

Enzymatic acylation of di- and trisaccharides with fatty acids: choosing the appropriate enzyme, support and solvent

Biocatalysis in Organic Media

Effect of Reaction Parameters on Synthesis of Citronellyl Methacrylate by Lipase‐Catalyzed Transesterification

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