- Genome mining reveals new bacterial type I Baeyer-Villiger monooxygenases with (bio)synthetic potential
-
Baeyer-Villiger monooxygenases (BVMOs) are oxidorreductases that catalyze the oxidation of ketones in a very selective manner. By genome mining we detected seven putative type I BVMOs in Bradyrhizobium diazoefficiens USDA 110. As we established the phylogenetic relationships among them and with other type I BVMOs, we found out that they belong to different clades of the phylogenetic tree. Thus, we decided to clone and heterologously express five of them. Three of them, each one from a divergent phylogenetic group, were obtained as soluble proteins, allowing us to proceed with their biocatalytic assessment and enzymatic characterization. As to substrate scope and selectivity, we observed a complementary behavior among the three BVMOs. BVMO2 was the more versatile biocatalyst in whole-cell systems while BVMO4 and BVMO5 showed a narrow substrate profile with preference for linear ketones and particular regioselectivity for (±)-cis-bicyclo[3.2.0]hept-2-en-6-one.
- Bianchi, Dario A.,Carabajal, María Ayelén,Ceccoli, Romina D.,Rial, Daniela V.
-
-
- Synthesis of butyrate using a heterogeneous catalyst based on polyvinylpolypyrrolidone
-
A heterogeneous polyvinylpolypyrrolidone supported Br?nsted acidic catalyst ([PVPP-BS]HSO4) was used to synthesize butyrate in this paper. The prepared catalysts were characterized by FT-IR, TG, and FESEM and their catalytic activity in butyric acid esterification with benzyl alcohol was investigated. The influencing factors such as the amount of catalyst, reaction temperature, and reaction time were carefully studied. Under the optimized condition with the butyric acid to benzyl alcohol mole ratio of 1 : 1.2 and the reaction temperature of 130°C, the yield of benzyl butyrate reached 96.8 % within 4 h in the presence of 8 mass % of catalyst. Moreover, the catalyst could be reused six times without noticeable drop in activity. This catalyst was also used to synthesize other kinds of butyrates achieving the butyrate yield above 90 %.
- Wang, Song,Chang, Qian-Qian,Shawgi, Nazar,Li, San-Xi,Zhang, Lin-Nan
-
p. 538 - 544
(2016/03/05)
-
- Ultrasound technology and molecular sieves improve the thermodynamically controlled esterification of butyric acid mediated by immobilized lipase from Rhizomucor miehei
-
In this research, the effects of ultrasound stirring and the addition of molecular sieves on esterification reactions between butyric acid and several alcohols catalyzed by immobilized lipase from Rhizomucor miehei (Lipozyme RM-IM) were studied. Among the tested alcohols, 1-propanol and isobutanol allowed the highest activities, whereas Lipozyme RM-IM showed poor activities for esterification using secondary and tertiary alcohols. Different solvents were also tested and n-hexane was selected because of its reaction effects, besides being cheaper, available at low boiling point, and ease of recovery. Using the preselected alcohol and solvent, other reaction parameters (butyric acid concentration, temperature, substrate molar rate, and biocatalyst content) were studied to optimize the reaction conditions. Optimal conditions were acid concentration, 0.7 M; substrate molar ratio, 11 alcohol-acid; temperature 45 °C; biocatalyst content, 14% (by substrate mass). Under these conditions, it was possible to obtain a yield of 86% of butyl butyrate in 2.5 h. When molecular sieves (90 mg mmol-1 butytic acid) were added to the reaction, the observed yield increased to 96%. The biocatalyst was used in 5 successive reaction cycles keeping 100% of its initial activity. The overall process productivity was improved 2-fold when compared to the traditional mechanical agitation, showing that ultrasound is a promising technology for application in biocatalysis. The Royal Society of Chemistry.
- Fallavena, Lucas P.,Antunes, Fabio H. F.,Alves, Joana S.,Paludo, Natalia,Ayub, Marco A. Z.,Fernandez-Lafuente, Roberto,Rodrigues, Rafael C.
-
p. 8675 - 8681
(2014/03/21)
-
- Comparison of the performance of commercial immobilized lipases in the synthesis of different flavor esters
-
In this work, it is compared the performance of three commercial lipase preparations (Novozym 435, Lipozyme TL-IM, and Lipozyme RM-IM) in the synthesis of flavor esters obtained by esterification of acetic, propionic, and butyric acids using ethanol, isopropyl alcohol, butanol, or pentanol. A comprehensive comparison was performed verifying activities of these three enzyme preparations versus the different couples of substrates, checking the obtained yields. In general, the longer the acid chain, the higher the reaction yields. Novozym 435 was the most efficient enzyme in most cases, and only Lipozyme RM-IM offered better results than Novozym 435 in the production of ethyl butyrate. Reactions with butyric acid showed the highest conversion rates using all biocatalysts. Using optimal substrates, the reactions catalyzed by the three enzymes were optimized using the response surface methodology, and the catalytic performance of the biocatalysts in repeated batches was assessed. After optimization, yields higher than 90% were obtained for all three enzymes, but Lipozyme TL-IM needed four-times more biocatalyst content than the other two preparations. Novozym 435 kept over 80% of its activity when reused in 9 successive batches, whereas Lipozyme RM-IM can be reused 5 times and Lipozyme TL-IM only 3 times. In general, Novozym 435 showed to be more suitable for these reactions than the other two enzyme preparations.
- Martins, Andrea B.,Da Silva, Alexandre M.,Schein, Mirela F.,Garcia-Galan, Cristina,Zachia Ayub, Marco A.,Fernandez-Lafuente, Roberto,Rodrigues, Rafael C.
-
-
- Discovery of Baeyer-Villiger monooxygenases from photosynthetic eukaryotes
-
Baeyer-Villiger monooxygenases are attractive "green" catalysts able to produce chiral esters or lactones starting from ketones. They can act as natural equivalents of peroxyacids that are the catalysts classically used in the organic synthesis reactions, consisting in the cleavage of CC bonds with the concomitant insertion of an oxygen atom. In this study, two type I BVMOs have been identified for the first time in photosynthetic eukaryotic organisms, the red alga Cyanidioschyzon merolae (Cm) and the moss Physcomitrella patens (Pp). A biocatalytic characterization of these newly discovered enzymes, expressed in recombinant forms, was carried out. Both enzymes could be purified as holo enzymes containing a FAD cofactor. Their thermostability was investigated and revealed that the Cm-BVMO is the most thermostable type I BVMO with an apparent melting temperature of 56 C. Substrate profiling revealed that both eukaryotic BVMOs accept a wide range of ketones which include aromatic, aliphatic, aryl aliphatic and bicyclic ketones. In particular, linear aliphatic ketones (C9 and C12), carrying the keto functionality in different positions, resulted to be the best substrates in steady state kinetic analyses. In order to restore the BVMO-typifying sequence motif in the Pp-BVMO, a mutant was prepared (Y160H). Intriguingly, this mutation resulted in higher activities on most tested substrates. The recombinant enzymes displayed kcat values in the 0.1-0.2 s-1 range, which is relatively low when compared with other known type I BVMOs. This may hint to a role in secondary metabolism in these photosynthetic organisms, though their exact function remains to be established.
- Beneventi, Elisa,Niero, Mattia,Motterle, Riccardo,Fraaije, Marco,Bergantino, Elisabetta
-
p. 145 - 154
(2013/12/04)
-
- Rapeseed lipase catalyzed synthesis of butyl butyrate for flavour and nutraceutical applications in organic media
-
Butyl butyrate, a short chain ester with fine fruity pineapple odour, is a significant flavour compound. Recent investigations show that butyrate esters also have anticancer activity. Factors influencing the synthesis of butyl butyrate by organic phase biocatalysis were investigated. Maximum ester yield of 89% was obtained when 0.25 M butanol and butyric acid were reacted at 25 °C for 48 h in the presence of 250 mg rape seed lipase acetone powder in hexane. Addition of water did not affect synthesis, while a water activity of 0.45 was found optimum. Of 15 different alcohols evaluated, isoamyl and (Z)-3- hexen-1-ol were esterified most effectively with molar conversion yields of 92.2 and 80.2%. Short chain primary alcohols such as methanol and medium-long chain alcohols, such as heptanol and octanol were esterified more slowly. The results show that rape seed lipase is versatile catalyst for ester synthesis with temperature stability range 5-50 °C.
- Liaquat, Muhammad
-
experimental part
p. 6 - 13
(2012/06/18)
-
- Synthesis of short chain alkyl esters using cutinase from Burkholderia cepacia NRRL B2320
-
Short chain alkyl esters are well appreciated for fruity flavors they provide. These are mainly applied to the fruit-flavored products like jam, jelly, beverages, wine and dairy. Cutinase from Burkholderia cepacia NRRL B 2320 was found to be active in catalyzing the synthesis of alkyl esters in organic solvent. The optimal temperature range for the enzyme catalyzed synthesis was found to be from 35 °C to 40 °C. The maximum conversion (%) during synthesis of ester was obtained for butyric acid (C4) and valeric acid (C5) with butanol reflecting the specificity of the enzyme for short-chain length fatty acids. In case of alcohol specificity, butanol was found to be most preferred substrate by the enzyme and conversion (%) decreased with increasing carbon chain length of alcohol used in the esterification reaction. The kinetic analysis for the synthesis of butyl butyrate by varying concentration of one substrate at a time (butanol or butyric acid), showed that Ping-Pong Bi Bi model with acid inhibition and influence of initial water is most suitable model for the prediction of the reaction kinetics.
- Dutta, Kasturi,Dasu, Veeranki Venkata
-
experimental part
p. 150 - 156
(2012/07/01)
-
- Solvent-free esterification catalyzed by surfactant-combined catalysts at room temperature
-
Solvent-free esterifications of various carboxylic acids and alcohols can be catalyzed by surfactant-combined catalysts dodecylbenzene sulfonic acid (DBSA) and copper dodecylbenzene sulfonate (CDBS) in moderate to excellent yield at room temperature. The esterification method has two notable advantages: first, there is no need for any solvent, even water, and secondly, no need for energy, the reaction can proceed smoothly at room temperature. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Gang, Li,Xinzong, Li,Eli, Wumanjiang
-
p. 348 - 351
(2008/02/10)
-
- Cesium fluoride-Celite: A solid base for efficient syntheses of aromatic esters and ethers
-
Coupling reactions of a number of aromatic and heteroaromatic phenols with alkyl, acyl or benzoyl halides in acetonitrile with cesium fluoride-Celite are described, demonstrating that this reagent provides an efficient, convenient and practical method for the syntheses of aromatic esters and ethers.
- Shah, Syed Tasadaque Ali,Khan, Khalid Mohammed,Hussain, Hidayat,Anwar, Muhammad Usman,Fecker, Miriam,Voelter, Wolfgang
-
p. 6652 - 6656
(2007/10/03)
-
- Structure-function correlation in lipase catalysed esterification reactions of short and medium carbon chain length alcohols and acids
-
An attempt has been made to correlate the carbon chain lengths of acids and alcohols to the extent of esterification in the Rhizomucor miehei lipase catalyzed esterification reactions involving acids of carbon chain length C2-C5 and alcohols of carbon chain length C1-C8.
- Divakar, Soundar
-
p. 1919 - 1922
(2007/10/03)
-
- Preparation of salicylic acid resin supported FeCl3 lewis acid catalyst and its application in organic synthesis
-
The catalytic effects of salicylic acid resin supported FeCl3 catalyst on the esterification of alcohol and carboxylic acid and on the acetalization (ketal formation) of aldehyde (ketone) and alcohol have been investigated.This catalyst is convenient to use, noncorrosive, easy to be separated from reactants and can be repeatedly used.
- Huirong, Yang,Yingde, Li Bina Cui
-
p. 1233 - 1238
(2007/10/03)
-
- Microwave radiation can increase the rate of enzyme-catalysed reactions in organic media
-
Irradiating a hydrated lipase enzyme suspended in organic media using microwaves (2.45 GHz, 50°C) enhanced the reaction rate by 2-3 fold over classical heating and the apparent non-thermal effects observed were dependent on the hydration state of the enzyme in the organic medium.
- Parker, Marie-Claire,Besson, Thierry,Lamare, Sylvain,Legoy, Marie-Dominique
-
p. 8383 - 8386
(2007/10/03)
-
- A study on synthesis of esters by superacid resin catalysts
-
Superacid resin as catalyst, instead of the strong acid cation exchange resin and sulfuric acid was used to synthesis n-butyl lactate. Some factors affection reaction, such as time, moles ratio of reactants and catalyst amount were studied. Results made known that time was shorten very much. Under our optimum conditions the ester yield was over 99.5%. In the other hand, superacid resin as catalyst was used to synthesis other esters, had result of raise ester yield and shorten the time of esterification.
- Yang,Li,Fang
-
p. 3269 - 3275
(2007/10/02)
-
- ENZYMATIC REACTIONS IN ORGANIC SYNTHESIS: 2- ESTER INTERCHANGE OF VINYL ESTERS
-
Ester interchange of vinyl esters appears to be a rapid and efficient way to obtain esters of primary and secondary alcohols, provided there is a hydrogen atom on the carbon adjacent to the carbonyl of the acyl moiety.
- Degueil-Castaing, M.,Jeso, B. De,Drouillard, S.,Maillard, B.
-
p. 953 - 954
(2007/10/02)
-