106-27-4Relevant articles and documents
Lipase-catalyzed synthesis of isoamyl butyrate: Optimization by response surface methodology
Krishna, S. Hari,Manohar,Divakar,Karanth
, p. 1483 - 1488 (1999)
Immobilized lipase from Mucor miehei (Lipozyme IM-20) was employed in the esterification of butyric acid and isoamyl alcohol to synthesize isoamyl butyrate in n-hexane. Response surface methodology based on five-level, five-variable central composite rotatable design was used to evaluate the effects of important variables - enzyme/substrate (E/S) ratio (5-25 g/mol), acid concentration (0.2-1.0 M), alcohol concentration (0.25-1.25 M), incubation period (12-60 h), and temperature (30-50 °C) - on esterification yield of isoamyl butyrate. In the range of parameters studied, the extent of esterification decreased with temperature, lower E/S ratios, and incubation periods. Excess acid and alcohol concentrations (i.e., acid/alcohol>1.4 or alcohol/acid>1.4) were found to decrease yield probably owing to inhibition of the enzyme by acid or alcohol, the former being more severe. The optimal conditions achieved are as follows: E/S ratio, 17 g/mol; acid concentration, 1.0 M; incubation period, 60 h; alcohol concentration, 1.25 M; and temperature, 30 °C. With these conditions, the predicted value was 1.0 M ester, and the actual experimental value was 0.98 M.
Efficient Enzymatic Preparation of Flavor Esters in Water
Perdomo, Igor Chiarelli,Gianolio, Stefania,Pinto, Andrea,Romano, Diego,Contente, Martina Letizia,Paradisi, Francesca,Molinari, Francesco
, p. 6517 - 6522 (2019/06/20)
A straightforward biocatalytic method for the enzymatic preparation of different flavor esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalyzed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and proceeded with excellent yields (80-97%) and short reaction times (30-120 min), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared with already known methods in terms of reduced use of organic solvents, paving the way to sustainable and efficient preparation of natural flavoring agents.
The combine use of ultrasound and lipase immobilized on co-polymer matrix for efficient biocatalytic application studies
Badgujar, Kirtikumar Chandulal,Bhanage, Bhalchandra Mahadeo
, p. 255 - 264 (2015/10/28)
In this work, we have investigated the combine use of ultrasound and lipase (Pseudomonas cepacia: PCL) immobilized on co-polymer of polyvinyl alcohol (PVA) and chitosan (CHI) for biocatalytic applications. Initially, we have screened different free and immobilized biocatalysts to find-out the robust biocatalyst. The immobilized biocatalyst PVA:CHI:PCL (5:5:2.5) worked as a robust biocatalyst to provide superior conversion (99%) for the synthesis of model ultrasound assisted reaction. Subsequently, various reaction parameters were optimized in details to obtain the higher yield. Besides this, developed biocatalytic protocol was used to synthesize various industrially important butyrate compounds which provided excellent conversion of 99% under ultrasonic conditions. The developed biocatalyst showed excellent recyclability upto studied five cycles under ultrasonic condition. The immobilized PVA:CHI:PCL biocatalyst displayed 2.4 folds higher activity as compared to free lipases in ultrasonic condition. Moreover, PVA:CHI:PCL biocatalyst in ultrasound media showed 4.5 folds higher activity as compared to free lipases in conventional media. The energy assessment was performed which demonstrated feasibility of combine use of immobilization and ultrasonication to carry out efficient biocatalytic process.
A clean enzymatic process for producing flavour esters by direct esterification in switchable ionic liquid/solid phases
Lozano, Pedro,Bernal, Juana M.,Navarro, Alicia
, p. 3026 - 3033 (2013/01/15)
A clean biocatalytic approach for producing flavour esters using switchable ionic liquid/solid phases as reaction/separation media has been developed. The phase behaviour of different IL/flavour acetyl ester (geranyl acetate, citronellyl acetate, neryl acetate and isoamyl acetate) mixtures was studied at several concentrations, resulting for all cases in fully homogeneous liquid media at 50 °C, and solid systems at room temperature. By using an iterative centrifugation protocol on the solid IL/flavour ester mixtures at controlled temperatures, the solid IL phase and the liquid flavour ester phase can be easily separated. The excellent suitability of an immobilized Candida antarctica lipase B (Novozym 435) catalyst in the esterification reaction between an aliphatic carboxylic acid (acetic, propionic, butyric or valeric) and a flavour alcohol (isoamyl alcohol, nerol, citronellol or geraniol) in N,N′,N′′,N′′′-hexadecyltrimethyl-ammonium bis(trifluoromethylsulfonyl)imide ([C16tma][NTf2])IL has been demonstrated, the product yield being improved up to 100% under appropriate reaction conditions (enzyme amount, dehydrating molecular sieves, etc.) at 50 °C. The enzymatic synthesis of sixteen different flavour esters was carried out in [C16tma][NTf2] by means of this approach, providing products of up to 0.757 g mL-1 concentration after IL separation. The residual activity of the enzyme/IL system during seven consecutive operation cycles was shown to be practically unchanged after reuse.
