| alcohol inhibition and specificity studies of lipase b from candida antarctica in organic solvents | alcohol inhibition of the lipase b from candida antarctica has been studied through two different approaches: using the same inhibitor (1-butanol) in different organic solvents and using different inhibitors (differing in chain length) in the same solvent. the competitive inhibition constant values obtained in each case correlate with the calculated activity coefficients of the substrate, suggesting that desolvation of the alcohol is the major force changed. data dispersion observed using the se ... | 1998 | 10099327 |
| a model of the pressure dependence of the enantioselectivity of candida rugosalipase towards (+/-)-menthol. | transesterification of (+/-)-menthol using propionic acid anhydride and candida rugosa lipase was performed in chloroform and water at different pressures (1, 10, 50, and 100 bar) to study the pressure dependence of enantioselectivity e. as a result, e significantly decreased with increasing pressure from e = 55 (1 bar) to e = 47 (10 bar), e = 37 (50 bar), and e = 9 (100 bar). to rationalize the experimental findings, molecular dynamics simulations of candida rugosa lipase were carried out. anal ... | 2001 | 11567085 |
| expedient synthesis of (r)-patulolide a. | an efficient derivation of the title compound has been formulated from easily accessible 10-undecenoic acid (1). thus, dodec-11-en-2-ol (3), prepared from 1, was pyranylated and subjected to bromination with nbs followed by acetolysis to furnish (2e)-1-acetoxy-11-(tetrahydropyranyloxy)dodec-2-ene (5). its hydrolysis, oxidation, and depyranylation afforded the (2e)-hydroxy ester (9). this, on candida rugosa lipase-catalyzed acetylation, seo(2) oxidation, hydrolysis, and yamaguchi macrolactonizati ... | 1996 | 11667053 |
| structure and conformational flexibility of candida rugosa lipase. | three-dimensional structures of a number of lipases determined in the past decade have provided a solid structural foundation for our understanding of lipase function. the structural studies of candida rugosa lipase summarized here have addressed many facets of interfacial catalysis. these studies have revealed a fold and catalytic site common to other lipases. different conformations likely to correlate with interfacial activation of the enzyme were observed in different crystal forms. the stru ... | 1999 | 10570248 |
| production of sophorolipids from whey. ii. product composition, surface active properties, cytotoxicity and stability against hydrolases by enzymatic treatment. | sophorolipids, obtained by a two-stage process starting from deproteinized whey concentrate using cryptococcus curvatus atcc 20509 and candida bombicola atcc 22214, were compared to products from one-stage processes, using different lipidic compounds as substrates. results showed that above all carbon source and not cultivation conditions had a distinct influence on the composition of the crude product mixture and therefore on the physicochemical and biological properties of the sophorolipids, s ... | 1999 | 10570796 |
| kinetics study of palm oil hydrolysis using immobilized lipase candida rugosa in packed bed reactor. | continuous hydrolysis of palm oil triglyceride in organic solvent using immobilized candida rugosa on the amberlite mb-1 as a source of immobilized lipase was studied in packed bed reactor. the enzymatic kinetics of hydrolysis reaction was studied by changing the substrate concentration, reaction temperature and residence time(tau) in the reactor. at 55 degrees c, the optimum water concentration was found to be 15 % weight per volume of solution (%w/v). the michaelis-menten kinetic model was use ... | 1999 | 10595442 |
| enantioselective synthesis of (s)-ibuprofen ester prodrug in cyclohexane by candida rugosa lipase immobilized on accurel mp1000. | an enantioselective esterification process was developed for the synthesis of 2-n-morpholinoethyl (s)-ibuprofen ester prodrug from racemic ibuprofen by using candida rugosa lipase immobilized on accurel mp1000 in cyclohexane. compared with the performance of lipase my, the immobilized lipase possesses a higher enzyme activity and thermal stability, but with a slightly suppressed enantioselectivity. a kinetic model was proposed and confirmed from experiments, for the simulation of time-course con ... | 2000 | 11101325 |
| candida rugosa lipase reactions in nonionic w/o-microemulsion with a technical surfactant. | in enzyme catalysis there is a great interest in finding suitable organic media for less water soluble substrates in order to increase the substrate concentration and therefore the reaction rates. these requirements are fulfilled by using w/o-microemulsions as reaction media. the influences of ph, temperature, water concentration and the kinetic parameters of candida rugosa lipase in a nonionic w/o-microemulsion with a surfactant of technical grade, marlipal o13-60, are presented. in an example ... | 2001 | 11118597 |
| differentiation between lutein monoester regioisomers and detection of lutein diesters from marigold flowers (tagetes erecta l.) and several fruits by liquid chromatography-mass spectrometry. | liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (lc-apcims) was employed for the identification of eight lutein monoesters, formed by incomplete enzymatic saponification of lutein diesters of marigold (tagetes erecta l.) by candida rugosa lipase. additionally, the main lutein diesters naturally occurring in marigold oleoresin were chromatographically separated and identified. the lc-ms method allows for characterization of lutein diesters occurring as minor compo ... | 2002 | 11754543 |
| fatty acid steryl, stanyl, and steroid esters by esterification and transesterification in vacuo using candida rugosa lipase as catalyst. | sterols (sitosterol, cholesterol, stigmasterol, ergosterol, and 7-dehydrocholesterol) and sitostanol have been converted in high to near-quantitative yields to the corresponding long-chain acyl esters via esterification with fatty acids or transesterification with methyl esters of fatty acids or triacylglycerols using lipase from candida rugosa as biocatalyst in vacuo (20-40 mbar) at 40 degrees c. neither organic solvent nor water is added in these reactions. under similar conditions, cholestero ... | 2001 | 11170561 |
| enzymatic hydrolysis of carotenoid fatty acid esters of red pepper (capsicum annuum l.) by a lipase from candida rugosa. | analyses of red pepper extracts which had been pretreated with lipase type vii (ec 3.1.1.3.) from candida rugosa showed for the first time pepper carotenoid esters to be substrates of this enzyme. however, the extent of enzymatic hydrolysis depends on the respective carotenoid and was not quantitative compared to chemical saponification. after enzymatic cleavage, 67-89% of total capsanthin, 61-65% of total zeaxanthin, 70-81% of total beta-cryptoxanthin and 70-86% of total violaxanthin were detec ... | 2000 | 11204204 |
| molecular basis for enantioselectivity of lipase from chromobacterium viscosum toward the diesters of 2,3-dihydro-3-(4'-hydroxyphenyl)-1,1,3-trimethyl-1h-inden-5-ol. | 2,3-dihydro-3-(4'-hydroxyphenyl)-1,1,3-trimethyl-1h-inden-5-ol, 1, is a chiral bisphenol useful for preparation of polymers. previous screening of commercial hydrolases identified lipase from chromobacterium viscosum (cvl) as a highly regio- and enantioselective catalyst for hydrolysis of diesters of 1. the regioselectivity was > or =30:1 favoring the ester at the 5-position, while the enantioselectivity varied with acyl chain length, showing the highest enantioselectivity (e = 48 +/- 20 s) for ... | 2001 | 11325269 |
| [studies on lipase production from candida rugosa]. | we studied some factors affecting the lipase production from candida rugosa, they mainly included medium compositions and culture condition. the result showed that the optimal medium compositions for lipase production are 0.1% glucose 4.0% olive oil (carbon source), 0.3% nh4no3(nitrogen source), 1.2% k2hpo4 and 0.4% mgso4.7h2o. and the optimal culture condition is initial ph6.5, temperature 30 degrees c, agitation 180 r/min and time 60 h. as a result, and the lipase activity could reach 19.5 u/m ... | 2001 | 11330177 |
| isolation of candida rugosa from turkeys. | the present study describes the isolation of candida rugosa from young turkeys that died 10 days after the end of a therapeutic treatment for a recent outbreak of coccidiosis. candida rugosa was isolated from the digestive tract of all the birds examined. this isolation is the first in turkeys and corroborates the fact that c. rugosa is an opportunistic yeast which circumvents host defences when other predisposing factors are present. | 2000 | 11014064 |
| analysis of conformational states of candida rugosa lipase in solution: implications for mechanism of interfacial activation and separation of open and closed forms. | in this study, an analysis of the transition between the inactive ("closed") and active ("open") conformations of candida rugosa lipase in solution is performed using irreversible enzyme inhibitors, cyclic saligenin phosphates. it is shown that >90% inhibition of the enzyme activity toward water-soluble substrates (esterolytic activity) can be achieved with as little as 0.3 mol of the inhibitor per mole of enzyme, whereas activity toward emulsified substrates decreases by approximately 20% under ... | 2001 | 11084600 |
| mutants provide evidence of the importance of glycosydic chains in the activation of lipase 1 from candida rugosa. | sequence analysis of candida rugosa lipase 1 (lip1) predicts the presence of three n-linked glycosylation sites at asparagine 291, 314, 351. to investigate the relevance of sugar chains in the activation and stabilization of lip1, we directed site mutagenesis to replace the above mentioned asparagine with glutamine residues. comparison of the activity of mutants with that of the wild-type (wt) lipase indicates that both 314 and 351 asn to gln substitutions influence, although at a different exte ... | 2000 | 10850808 |
| safety evaluation of lipase produced from candida rugosa: summary of toxicological data. | the toxicity of lipase ay, an enzyme preparation used in lipid hydrolysis to produce flavors, was evaluated in a series of studies. a 13-week dietary toxicity study in sprague-dawley (crj:cd) rats was conducted in which animals received lipase ay in the feed at concentrations of 0, 625, 1250, or 2500 mg/kg body wt. no adverse treatment-related effects were observed. lack of genotoxic potential was demonstrated by the results of an in vitro reverse mutation assay in salmonella typhimurium strains ... | 2001 | 11350198 |
| recombinant expression and characterization of the candida rugosa lip4 lipase in pichia pastoris: comparison of glycosylation, activity, and stability. | although candida rugosa utilizes a nonuniversal serine codon (cug) for leucine, it is possible to express lipase genes (lip) in heterologous systems. after replacing the 19 cug codons in lip4 with serine codons by site-directed mutagenesis, a recombinant lip4 was functionally overexpressed in pichia pastoris in this study. this recombinant glycosylated lipase was secreted into the culture medium with a high purity of 100 mg/liter in a culture broth. purified recombinant lip4 had a molecular mass ... | 2001 | 11368188 |
| immobilization of candida rugosa lipase on colloidal gas aphrons (cgas). | a novel technique for immobilization of candida rugosa lipase onto anionic colloidal gas aphrons (cgas) is described. cgas are spherical microbubbles (10-100 microm) composed of an inner gas core surrounded by a surfactant shell. in this initial study, greater than 80% lipase (w/w) was effectively retained on the cgas. leakage of protein from the cgas and the activity of the adsorbed lipase decreased with increasing enzyme loading; this indicates that multilayers of lipase may be adsorbing onto ... | 2001 | 11400100 |
| synthesis of glycerides containing n-3 fatty acids and conjugated linoleic acid by solvent-free acidolysis of fish oil. | menhaden oil, a rich source of n-3 fatty acids, was interesterified with conjugated linoleic acid (cla) in a reaction medium composed solely of substrates and either free or immobilized commercial lipase preparations. of five lipases tested, an immobilized preparation from mucor miehei provided the fastest rate of incorporation of cla into fish oil acylglycerols; however, and as observed with most of the lipases utilized, a significant proportion of the n-3 fatty acid residues were liberated in ... | 2000 | 11042555 |
| study of lipase-catalyzed hydrolysis of some monoterpene esters. | studies of the hydrolysis of bornyl, citronellyl, geranyl, and terpenyl acetates by commercially available lipases of candida rugosa, rhizopus arrhizus, and mucor miehei are presented. the hydrolysis of these monoterpene esters is investigated at various temperatures and phs, and the time dependence of the percentage of esters hydrolysed is studied. the catalytic activities of the lipases in hydrolysing the esters are compared and, overall, it is observed that under the experimental conditions u ... | 2001 | 11400729 |
| incidence of candida in psoriasis--a study on the fungal flora of psoriatic patients. | the presence of candida albicans and other candida species in saliva and faeces of 50 psoriatic patients compared with a control group of 50 healthy donors was examined quantitatively. the quantity of candida in saliva and faeces of the psoriatics proved to be significantly higher than in the controls. candida was detected in 78% of the saliva samples of the psoriatics but in only 50% of the controls, and in the faeces samples in 72% of the psoriatics, but in only 46% of the controls. qualitativ ... | 2001 | 11413927 |
| influence of the conformational flexibility on the kinetics and dimerisation process of two candida rugosa lipase isoenzymes. | we have investigated the interfacial activation process of two isoenzymes from candida rugosa (lip1 and lip3) using triacetin as substrate. kinetics were coupled to inhibition experiments in order to analyse the transition between the open and closed conformers. this process was slow, particularly for lip1, in the absence of an interface provided by the substrate or a detergent. dimers of lip3 were also purified and their catalytic action was closer to that of a typical esterase. in spite of the ... | 2001 | 11457462 |
| novel lipase-catalysed enantioselective deacetylation of (+/-)-5-acetoxy-3-(4-fluorophenyl)-2-phenylisoxazolidine. | (+/-)-5-acetoxy-3-(4-fluorophenyl)-2-phenylisoxazolidine has been synthesised by a highly diastereoselective [3+2] cycloaddition reaction between alpha-(4-fluorophenyl)-n-phenylnitrone and vinyl acetate in good yield. candida rugosa lipase catalyses the deacetylation of this (+/-)-5-acetoxyisoxazolidine in a highly enantioselective fashion in diisopropyl ether containing n-butanol affording (-)-5-acetoxy-3-(4-fluorophenyl)-2-phenylisoxazolidine in 43% yield and >99% ee. | 2001 | 11514151 |
| effect of water activity and immobilization on fatty acid selectivity for esterification reactions mediated by lipases. | the effect of water activity (a(w)) and immobilization on fatty acid (fa) selectivity of burkholderia (formerly pseudomonas) cepacia, rhizomucor miehei, candida antarctica (type b), and candida rugosa lipases in esterification reactions was determined. studies were based on measuring ester formation in multicompetitive reaction mixtures containing either the homologous series of even carbon number n-chain saturated fa (c4-c18) or a series of n-chain (un)saturated fa (c18:x, where x = 0-3 double ... | 2001 | 11536145 |
| the his gap motif in microbial lipases: a determinant of stereoselectivity toward triacylglycerols and analogs. | lipases preferably hydrolyze the sn-1 and sn-3 acyl chain of triacylglycerols and sn-2 substituted analogs. molecular modeling studies of the stereopreference of microbial lipases from rhizopus oryzae, rhizomucor miehei, candida rugosa, and lipase b from candida antarctica toward the hydrolysis of triacylglycerols and analogs revealed that sterical interactions occurring between the sn-2 substituent and the his gap affect substrate geometry, which can be monitored by a single torsion angle. this ... | 2000 | 11099801 |
| lipase-catalyzed asymmetric desymmetrization of prochiral 2,2-disubstituted 1,3-propanediols using 1-ethoxyvinyl benzoate. | the lipase-catalyzed asymmetric desymmetrization of the prochiral 2,2-disubstituted 1,3-propanediols was studied using various types of 1-ethoxyvinyl esters (1a-i). although 1a-e with aliphatic acyl groups were not sufficient, use of the benzoate (1f) in combination with candida rugosa lipases converted acyclic diols (2, 6) and cyclic diols (11-14) to the optically active compounds (3f, 7f, 15f-18f), bearing a quaternary carbon center, with moderate-to-high optical yields. these products were fa ... | 2000 | 11045461 |
| lipase-catalyzed chemo- and enantioselective acetylation of 2-alkyl/aryl-3-hydroxypropiophenones. | the chemo- and enantioselective capabilities of porcine pancreatic lipase (ppl) in tetrahydrofuran, and candida rugosa lipase (crl) in diisopropyl ether have been investigated for the acetylation of racemic 2-alkyl/aryl-3-hydroxypropiophenones, which are important precursors in the synthesis of biologically active chromanones and isoflavanones. a highly chemoselective acetylation of primary hydroxy group in preference to phenolic hydroxy group leading to the formation of enantiomerically enriche ... | 2001 | 11557352 |
| an efficient derivation of the versatile chiron antipode 1-tert-butyldimethylsilylpenta-1,4-diyn-3-ol: application to the synthesis of (15e,r,r)-duryne. | the title chiron, 1-tert-butyldimethylsilylpenta-1,4-diyn-3-ol (5), an essential segment of various bioactive polyacetylenic alcohols, has been efficiently resolved via a lipase-catalyzed acylation strategy. lipases from different pseudomonas species and candida rugosa (crl) furnished its (s)-antipode (as esters) with 86-96% ee. however, the (r)-alcohol 5 could be prepared with acceptable enantiomeric purity (93% ee) only using crl-vinyl acetate-diisopropyl ether as the reagent protocol and unde ... | 1998 | 11672240 |
| lipase-catalysed hydrolysis of short-chain substrates in solution and in emulsion: a kinetic study. | we have studied the enzymatic hydrolysis of solutions and emulsions of vinyl propionate, vinyl butyrate and tripropionin by lipases of various origin and specificity. kinetic studies of the hydrolysis of short-chain substrates by microbial triacylglycerol lipases from rhizopus oryzae, mucor miehei, candida rugosa, candida antarctica a and by (phospho)lipase from guinea-pig pancreas show that these lipolytic enzymes follow the michaelis-menten model. surprisingly, the activity against solutions o ... | 2001 | 11750885 |
| blocking the tunnel: engineering of candida rugosa lipase mutants with short chain length specificity. | the molecular basis of chain length specificity of candida rugosa lipase 1 was investigated by molecular modeling and site-directed mutagenesis. the synthetic lip1 gene and the lipase mutants were expressed in pichia pastoris and assayed for their chain length specificity in single substrate assays using triglycerides as well as in a competitive substrate assay using a randomized oil. mutation of amino acids at different locations inside the tunnel (p246f, l413f, l410w, l410f/s300e, l410f/s365l) ... | 2002 | 12200542 |
| esterification of fatty acids using nylon-immobilized lipase in n-hexane: kinetic parameters and chain-length effects. | the esterification of long-chain fatty acids in n-hexane catalyzed by nylon-immobilized lipase from candida rugosa has been investigated. butyl oleate (22 carbon atoms), oleyl butyrate (22 carbon atoms) and oleyl oleate (36 carbon atoms) were produced at maximum reaction rates of approximately equal to 60 mmol h(-1) g(-1) immobilized enzyme when the substrates were present in equimolar proportions at an initial concentration of 0.6 mol l(-1). the observed kinetic behavior of all the esterificati ... | 2002 | 11755985 |
| hydrolysis of steryl esters by a lipase (lip 3) from candida rugosa. | a well-known lipase, lip 3 of candida rugosa, was purified to homogeneity from a commercial lipase preparation, using hydrophobic interaction and anion exchange chromatography. lip 3, which has been reported to act on cholesteryl esters, was also found to be active on plant-derived steryl esters. lip 3 had optimal activity at ph 5-7 and below 55 degrees c. it was able to hydrolyse steryl esters totally in a clear micellar aqueous solution. however, the action on a dispersed colloidal steryl este ... | 2002 | 12382052 |
| total synthesis of (s)-(+)-curcudiol, and (s)-(+)- and (r)-(-)-curcuphenol. | a highly enantioselective synthesis of the versatile chiral synthons possessing one stereogenic center, (s)- and (r)-4-aryl-5-hydroxy-(2e)-pentenoate (3) was achieved based on the enzymatic reaction of (+/-)-3 with commercially available lipases my-30 or of-360 from candida rugosa. application of (s)-3 and (r)-3 to the total syntheses of(s)-curcuphenol (1), (s)-curcudiol (2), and (r)-curcuphenol (1), respectively, is described. | 2001 | 11767078 |
| factors affecting the resolution of dl-menthol by immobilized lipase-catalyzed esterification in organic solvent. | among 10 lipases tested, candida rugosa lipase exhibited the best ability to catalyze the resolution of dl-menthol in organic solvent. the lipase was immobilized on different carriers, and the experiment was carried out with different acyl donors. the high yield and optical purity of the product were achieved in cyclohexane with valeric acid as acyl donor using c. rugosa lipase immobilized on deae-sephadex a-25. the conversion of dl-menthol depended on the water content of immobilized lipase and ... | 2002 | 11782192 |
| effect of acyl chain length and branching on the enantioselectivity of candida rugosa lipase in the kinetic resolution of 4-(2-difluoromethoxyphenyl)-substituted 1,4-dihydropyridine 3,5-diesters. | since 2,6-dimethyl-4-aryl-1,4-dihydropyridine 3,5-diesters themselves are not hydrolyzed by commercially available hydrolases, derivatives with spacers containing a hydrolyzable group were prepared. seven acyloxymethyl esters of 5-methyl- and 5-(2-propoxyethyl) 4-[2-(difluoromethoxy)phenyl]-2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylate were synthesized and subjected to candida rugosa lipase (crl) catalyzed hydrolysis in wet diisopropyl ether. a methyl ester at the 5-position and a long or b ... | 2002 | 11798310 |
| novel lipase-catalysed highly selective acetylation studies on d-arabino- and d-threo-polyhydroxyalkyltriazoles. | capabilities of lipases from candida antarctica, candida rugosa and porcine pancreas have been evaluated for regioselective acetylation of 2-phenyl-4-(d-arabino-tetrahydroxybutyl)-2h-1,2,3-triazole, 2-phenyl-4-(d-arabino-o-1',2'-isopropylidene-3',4'-dihydroxybutyl)-2h-1,2,3-triazole and 2-phenyl-4-(d-threo-trihydroxypropyl)-2h-1,2,3-triazole, precursors for the synthesis of triazolylacyclonucleosides. c. antarctica lipase and porcine pancreatic lipase exhibited exclusive selectivity for the acet ... | 2002 | 11836103 |
| selection of stabilizing additive for lipase immobilization on controlled pore silica by factorial design. | candida rugosa lipase was covalently immobilized on silanized controlled pore silica (cps) previously activated with glutaraldehyde in the presence of several additives to improve the performance of the immobilized form in long-term operation. proteins (albumin and lecithin) and organic molecules (beta-cyclodextrin and polyethylene glycol [peg]-1500) were added during the immobilization procedure, and their effects are reported and compared to the behavior of the immobilized biocatalyst in the a ... | 2001 | 11963898 |
| activity of candida rugosa lipase immobilized on gamma-fe2o3 magnetic nanoparticles. | we report the stability and enzymatic activity of candida rugosa lipase (e.c.3.1.1.3) immobilized on gamma-fe2o3 magnetic nanoparticles. the immobilization strategies were either reacting the enzyme amine group with a nanoparticle surface acetyl, or amine groups. in the former, the enzyme was attached through a c=n bond, while in the latter it was connected using glutaraldehyde. afm images show an average particle size of 20 +/- 10 nm after deconvolution. the enzymatic activity of the immobilize ... | 2003 | 12580578 |
| kinetic studies of lipase from candida rugosa: a comparative study between free and immobilized enzyme onto porous chitosan beads. | the search for an inexpensive support has motivated our group to undertake this work dealing with the use of chitosan as matrix for immobilizing lipase. in addition to its low cost, chitosan has several advantages for use as a support, including its lack of toxicity and chemical reactivity, allowing easy fixation of enzymes. in this article, we describe the immobilization of candida rugosa lipase onto porous chitosan beads for the enzymatic hydrolysis of olive oil. the binding of the lipase onto ... | 2001 | 11963902 |
| synthesis of optically active vicinal fluorohydrins by lipase-catalyzed deracemization. | three microbial lipases have been used to deracemize trans-2-fluorocycloalkanols 2 both by hydrolysis of the corresponding acetates 3 or chloroacetates 4 and by esterification of the fluorohydrins 2 using vinyl acetate and vinyl chloroacetate, respectively. pseudomonas cepacia lipase was the most selective for the six- and the seven-membered-ring compounds, while the lipase from candida rugosa was most useful for the eight-membered-ring compounds. both lipases transform the (r)-enantiomers prefe ... | 2002 | 11975561 |
| esterification activity and stability of candida rugosa lipase immobilized into chitosan. | microbial lipase from candida rugosa immobilized into porous chitosan beads was tested for esterification selectivity with butanol and different organic acids (c2-c12), and butyric acid and different aliphatic alcohols (c2-c10). after 24 h, the acids tested achieved conversions of about 40-45%. acetic acid was the only exception, and in this case butanol was not consumed. different alcohols led to butyric acid conversions >40%, except for ethanol, in which case butyric acid was converted only 26 ... | 2002 | 12018318 |
| [high expression of lip1 in pichia pastoris]. | the gene of lip1, the most important isoenzyme of candida rugosa lipase (crl), was artificially synthesized according to its mature peptide sequence. it consisted of 20 codons of preference in pichia pastoris. the artificial gene was cloned into methanol-inducible expression vector ppiczalphaa, and constitutive expression vector pgapzalphaa, respectively. the linearized recombinant plasmids were transformed into chromosome of pichia pastoris smd1168h strain by electroporation. the abilities of e ... | 2003 | 12673392 |
| multiple mutagenesis of non-universal serine codons of the candida rugosa lip2 gene and biochemical characterization of purified recombinant lip2 lipase overexpressed in pichia pastoris. | the 17 non-universal serine codons (ctg) in the candida rugosa lip2 gene have been converted into universal serine codons (tct) by overlap extension pcr-based multiple site-directed mutagenesis. an active recombinant lip2 lipase was overexpressed in pichia pastoris and secreted into the culture medium. the recombinant lip2 showed distinguishing catalytic activities when compared with recombinant lip4 and commercial c. rugosa lipase. the purified enzyme showed optimum activity at ph 7 and a broad ... | 2002 | 12020350 |
| formal total synthesis of (+)-macrosphelide a based on regioselective hydrolysis using lipase. | three kinds of seco-macrosphelide a congeners, (4r,5s,10r,11s,15s)-6, (4r,5s,9s,14r,15s)-7 and (3s,8r,9s,14r,15s)-8 were chemically synthesized, and they were exposed to the lipase of-360 from candida rugosa to give three hydroxy carboxylic acids, respectively. macrolactonization of the hydroxy acid (4r,5s,10r,11s)-18 derived from (4r,5s,10r,11s,15s)-6 gave 12-membered lactone (19) in 47% overall yield from 6, while that of the seco-acid (4) derived from (4r,5s,9s,14r,15s)-7 afforded (-)-dibenzy ... | 2002 | 12036034 |
| covalent coupling method for lipase immobilization on controlled pore silica in the presence of nonenzymatic proteins. | candida rugosa lipase was covalently immobilized on silanized controlled pore silica previously activated with glutaraldehyde in the presence of nonenzymatic proteins. this strategy is suggested to protect the enzyme from aggregation effects or denaturation that occurs as a result of the presence of silane precursors used in the formation of the silica matrix. the immobilization yield was evaluated as a function of the lipase loading and the additive type (albumin and lecithin) using statistical ... | 2003 | 12790642 |
| microwave-assisted rapid characterization of lipase selectivities. | a rapid screening procedure for characterization of lipase selectivities using microwaves was developed. the rate of reaction of various commercial lipases (porcine pancreas, mucor miehei, candida rugosa, pseudomonas cepacia) as well as lipases from laboratory isolates-bacillus stearothermophilus and burkholderia cepacia rgp-10 for triolein hydrolysis was 7- to 12-fold higher in a microwave oven as compared to that by ph stat. the esterification of sucrose/methanol and ascorbic acid with differe ... | 2002 | 12062110 |
| lipase-assisted generation of 2-methyl-3-furanthiol and 2-furfurylthiol from thioacetates. | enzymatic hydrolysis of s-3-(2-methylfuryl) thioacetate and s-2-furfuryl thioacetate using lipase from candida rugosa produced 2-methyl-3-furanthiol and 2-furfurylthiol, respectively. when reactions were carried out at room temperature and ph 5.8, 2-methyl-3-furanthiol was produced in a optimal yield of 88% after 15 min of reaction, whereas 2-furfurylthiol was obtained in a yield of 80% after 1 h of reaction time. enzymatic hydrolysis was also performed in n-hexane, n-pentane, and water/propylen ... | 2002 | 12083888 |
| enantiomeric resolution of 2-aryl propionic esters with hyperthermophilic and mesophilic esterases: contrasting thermodynamic mechanisms. | the enantiomeric resolution of 2-aryl propionic esters by hyperthermophilic and mesophilic esterases was found to be governed by contrasting thermodynamic mechanisms. entropic contributions predominated for mesophilic esterases from candida rugosa and rhizomucor miehei, while enthalpic forces controlled this resolution by the esterase from the extremely thermoacidophilic archaeon, sulfolobus solfataricus p1. this disparity in thermodynamic mechanism can be attributed to the differences in confor ... | 2002 | 12105890 |
| immobilization of lipase using hydrophilic polymers in the form of hydrogel beads. | the purpose of this study was to immobilize lipase (triacylglycerol ester hydrolase, e.c. 3.1.1.3) from candida rugosa using various polymers in the form of beads, to evaluate enzyme loading, leaching, and activity; and to characterize the beads. agarose, alginate, and chitosan were the polymers selected to immobilize lipase by entrapment. agarose beads exhibited undesirable swelling in the leaching and activity medium and the polymer was not used further. alginate or chitosan beads were prepare ... | 2002 | 12109688 |
| molecular weight and degree of deacetylation effects on lipase-loaded chitosan bead characteristics. | the effects of the molecular weight (mw) and degree of deacetylation (dd) of chitosan on chitosan hydrogel beads were characterized, and the entrapment efficiency, release of entrapped lipase, and activity of immobilized candida rugosa lipase were investigated. fresh and freeze-dried beads were characterized. a solution of lipase was prepared in a 1.5% (w/v) chitosan and 1% (v/v) acetic acid medium, and then dropped into a tripolyphosphate solution to prepare the beads. the release studies were ... | 2002 | 12109689 |
| production of native and recombinant lipases by candida rugosa: a review. | the yeast candida rugosa produces multiple lipase isoenzymes sharing high sequence homology but with some differences in their catalytic properties. the regulation of c. rugosa lipase (crl) synthesis and secretion in c. rugosa obeys a complex pattern. fermentation processes for both wild-type and mutant c. rugosa strains are available for lipase production. native crl preparations have been extensively used for biotransformations. however, their inherent mixture of isoforms with variable profile ... | 2001 | 11732718 |
| rice straw as a support for immobilization of microbial lipase. | candida rugosa lipase was covalently immobilized on rice straw activated with glutaraldehyde using poly(ethylene glycol) (peg) as the stabilizing agent. the effects of peg molecular weight and enzyme loading were studied according to a full 2(2) factorial design. higher immobilization yields (>70%) were attained when the lipase loading was 95 units/mg of dry support, independent of peg molecular weight. all derivatives showed high hydrolytic and synthetic activities. this work provides prelimina ... | 2001 | 11735441 |
| antimicrobial and anti-lipase activity of quercetin and its c2-c16 3-o-acyl-esters. | neither quercetin (q), nor 3-o-acylquercetines, up to 100 microg/ml, had any significant activity on selected gram-positive strains (staphylococcus aureus, bacillus subtilis, listeria ivanovi, listeria monocytogenes, listeria serligeri), gram-negative strains (escherichia coli, shigella flexneri, shigella sonnei, salmonella enteritidis, salmonella tiphymurium) and yeasts (candida albicans and candida glabrata). in addition, we confirmed the known anti-hiv activity of q (80% inhibition at 40 micr ... | 2002 | 11741775 |
| fine separation and characterization of candida rugosa lipase isoenzymes. | commercial candida rugosa lipase has been separated into two distinct fractions (crla and crlb) by anion-exchange chromatography. as analyzed on sds-polyacrylamide gel electrophoresis, crla and crlb are homogenous. at high ionic strength, crla and crlb have similar hydrophobicity and uv spectra, suggesting that the open extent of the large hydrophobic pockets of crla and crlb may be similar. at low ionic strength, using "hydrophobic interfacial affinity chromatography", both crla and crlb have b ... | 2002 | 12362407 |
| investigation of lipase-catalysed hydrolysis of naproxen methyl ester: use of nmr spectroscopy methods to study substrate-enzyme interaction. | (+/-)-2-(6-methoxy-2-naphthyl)propionic acid methyl ester (methyl ester of naproxen), the precursor of therapeutically important nonsteroidal anti-inflammatory drugs (nsaids) was enantioselectively hydrolysed using as biocatalyst candida rugosa lipase. in research aimed at studying the structure-activity relationship (sar), nmr spectroscopy methods were employed to identify which naproxen molecular moiety was essential to the substrate-enzyme interaction. the experimental results, in agreement w ... | 2002 | 12392706 |
| regioselective enzymatic hydrolysis of acetylated pyranoses and pyranosides using immobilised lipases. an easy chemoenzymatic synthesis of alpha- and beta-d-glucopyranose acetates bearing a free secondary c-4 hydroxyl group. | protected sugars with only one free hydroxyl group are useful building blocks for the synthesis of a large number of glycoderivatives. in order to avoid the problems of the classical chemical synthesis, we studied the regioselective enzymatic hydrolysis of different fully acetylated glycopyranoses and glycopyranosides. the main challenge was to obtain the hydrolysis of the substrates in only one position, with high regioselectivity, while avoiding any further hydrolysis towards partially acetyla ... | 2002 | 12423962 |
| a transformation system for the nonuniversal cug(ser) codon usage species candida rugosa. | since candida rugosa utilizes a nonuniversal serine codon cug rather than leucine, no vectors have been constructed to transform this organism. moreover, it is difficult to design a new transformation system because no selection markers and promoters are available. in this study, zeocin (400 microg/ml) was demonstrated to inhibit the growth of c. rugosa. the dominant selectable marker bleomycin-resistant determinant (ble) gene containing five cug codons in an open-reading frame of 375 bp was syn ... | 2003 | 12459243 |
| general trend of lipase to self-assemble giving bimolecular aggregates greatly modifies the enzyme functionality. | three microbial lipases (those from candida rugosa, humicola lanuginosa, and mucor miehei) have been found to exhibit a tendency to form bimolecular aggregates in solution even at very low enzyme concentrations (44 microg/ml) in the absence of a detergent, as detected by gel filtration. the monomolecular form of the enzymes was found as unique only at low enzyme concentration and in the presence of detergents. however, in the case of the lipase b from candida antarctica, no bimolecular form coul ... | 2003 | 12523838 |
| polymerization of propyl malolactonate in the presence of candida rugosa lipase. | to gain better insight into mechanistic features of enzyme-catalyzed malolactonate polymerization, reactions with propyl malolactonate were analyzed while varying enzyme concentration, reaction media composition, and reaction temperature. monomer conversion and product molecular weights were characterized by (1)h nmr and maldi-tof ms, respectively. a high extent of thermal polymerization of propyl malolactonate was observed, while the polymer chain length in all reactions was controlled by the e ... | 2003 | 12523841 |
| monitoring the transport of recombinant candida rugosa lipase by a green fluorescent protein-lipase fusion. | in a batch cultivation of pichia pastoris expressing candida rugosa lipase 1 (crl1), secretion of 200 microg lipase ml(-1) of culture was achieved in sorbitol-based medium. however, a large amount of recombinant protein was retained intracellularly throughout the fermentation, pointing to the transport step as a major bottleneck. therefore a translational fusion with the green fluorescent protein (gfp) was constructed that was expressed and transported similarly to the native lipase and retained ... | 2003 | 14719831 |
| crystallization and preliminary x-ray diffraction studies of two different crystal forms of the lipase 2 isoform from the yeast candida rugosa. | the yeast candida rugosa produces several closely related lipases which show a high degree of sequence identity (between 77 and 88% for pairs of proteins). despite this high sequence identity, they exhibit markedly different substrate specificities, indicating that subtle structural differences may produce significant functional changes. isoform 2 (lip2) has been crystallized using the hanging-drop vapour-diffusion method at 291 k. diffraction-quality crystals have been obtained from two differe ... | 2003 | 12595707 |
| behavior of silica aerogel networks as highly porous solid solvent media for lipases in a model transesterification reaction. | highly porous silica aerogels with differing balances of hydrophobic and hydrophilic functionalities were studied as a new immobilization medium for enzymes. two types of lipases from candida rugosa and burkholderia cepacia were homogeneously dispersed in wet gel precursors before gelation. the materials obtained were compared in a simple model reaction: transesterification of vinyl laurate by 1-octanol. to allow a better comparison of the hydrophobic/hydrophilic action of the solid, very open a ... | 2003 | 12616634 |
| impact of ionic liquid physical properties on lipase activity and stability. | lipase activity and stability was investigated in dialkylimidazolium and pyrrolidinium-based ionic liquids with a variety of anions including hexafluorophosphate, acetate, nitrate, methanesulfonate, trifluoroacetate, and trifluoromethylsulfonate. the initial rate of lipase-catalyzed transesterification of methyl methacrylate in these ionic liquids and several organic solvents was examined as well as the polytransesterification of divinyl adipate and 1,4-butanediol. free lipase (candida rugosa) c ... | 2003 | 12670234 |
| effect of reaction parameters on synthesis of citronellyl methacrylate by lipase-catalyzed transesterification. | 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 ... | 2003 | 12675563 |
| gelatin blends with alginate: gels for lipase immobilization and purification. | blends of natural polysaccharide sodium alginate (5%) with gelatin (3%) cross-linked with glutaraldehyde provide beads with excellent compressive strength (8 x 10(4) pa) and regular structure on treatment with calcium chloride. lipases from porcine pancreas, pseudomonas cepacia, and candida rugosa were immobilized in such a blend with excellent efficiency. the immobilized enzymes were stable and were reused several times without significant loss of enzyme activity both in aqueous and reverse mic ... | 2003 | 12675601 |
| purification of conjugated linoleic acid isomers through a process including lipase-catalyzed selective esterification. | a mixture of conjugated linoleic acids (clas) was prepared by alkali conjugation of high purity linoleic acid. the preparation contained 45.1 wt% cis-9, trans-11 (c9,t11)-cla, 46.8 wt% trans-10, cis-12 (t10,c12)-cla, and 5.3 wt% other clas. a process comprising candida rugosa lipase-catalyzed selective esterification with lauryl alcohol, molecular distillation, and urea adduct fractionation under strict conditions in ethanol was very effective for purification of c9,t11- and t10,c12-clas. in par ... | 2003 | 12843679 |
| chemical modification of lipases with various hydrophobic groups improves their enantioselectivity in hydrolytic reactions. | semi-purified lipases from candida rugosa, pseudomonas cepacia and alcaligenes sp. were chemically modified with a wide range of hydrophobic groups such as benzyloxycarbonyl, p-nitrobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl, t-butoxycarbonyl, lauroyl and acetyl moieties. the candida rugosa lipase my modified with the benzyloxycarbonyl group (modification ratio = 84%) brought about a 15-fold increase in enantioselectivity (e value) towards the hydrolysis of racemic butyl 2-(4-ethylphenoxy)pro ... | 2003 | 12882312 |
| lipase-catalyzed enantioselective esterification of (s)-naproxen hydroxyalkyl ester in organic media. | a lipase-catalyzed, enantioselective esterification process in organic solvents was developed for the synthesis of (s)-naproxen hydroxyalkyl ester. with the selection of lipase (candida rugosa lipase) and reaction medium (isooctane and cyclohexane), a high enantiomeric ratio of > 100 for the enzyme was obtained. 1,4-butanediol was the best acyl acceptor. the carbon chain length of the alcohol had a major effect on the enzyme activity and enantioselectivity of lipase-catalyzed esterification. | 2003 | 12882564 |
| evaluation of the catalytic activity of lipases immobilized on chrysotile for esterification. | in the present work, the ester synthesis in organic media catalyzed by lipases immobilized on chrysotile was studied. lipases of different sources (mucor javanicus, pseudomonas cepacia, rhizopus oryzae, aspergillus niger and candida rugosa) were immobilized on chrysotile, an inexpensive magnesium silicate, and used for esterification of hexanoic, octanoic and lauric acid with methanol, ethanol, 1-butanol and 1-octanol at 25 c in hexane as solvent. the best results were obtained with mucor javani ... | 2003 | 12894300 |
| lipases for biocatalysis: development of a chromatographic bioreactor. | the development of a new chromatographic reactor based on immobilized candida rugosa lipase (crl) is described. the chromatographic system has been used to evaluate the rate differences by which the product enantiomers of esterolytic reactions catalyzed by immobilized crl are obtained. the method has been applied to a series of racemic 2-aryloxyalkanoic acids and isosteric analogous methyl esters and to some non-steroidal antiinflammatory drugs 2-arylpropanoic acids methyl esters in order to stu ... | 2003 | 12899962 |
| activity of lipase in reversed micelles. | the enzyme activity of lipase from candida rugosa in aot isooctane reversed micelles was investigated. effect of ph, temperature, substrate concentration, waterpool (r value), choice of organic solvent, surfactant concentration on the activity of lipase were studied in detail. results indicate that the enzyme in reversed micelles follows the michaelis-menten dynamics temperature optimum=32.5 degrees, ph optimum=7.0, and maximum activity is reached at the concentration of olive oil of 40%. the en ... | 1999 | 12115008 |
| lipase-catalyzed acidolysis of menhaden oil with conjugated linoleic acid: effect of water content. | the effect of the water content on the lipase-catalyzed (candida rugosa) interesterification (acidolysis) of menhaden oil with conjugated linoleic acid was studied for amounts of added water ranging from 0-4% (w/w). the rate of the acidolysis reaction increased with increasing water content, but the corresponding percentage of n-3 fatty acids liberated also increased. the implications of water content for minimization of the release of n-3 fatty acid residues while maximizing incorporation of cl ... | 2002 | 12115120 |
| carotenol fatty acid esters: easy substrates for digestive enzymes? | to study the specificity of gastric lipases on carotenoid mono- and diesters, an enzymatic assay was applied. digestions were carried out in phosphate buffer at ph 7.4 and 37 degrees c. as substrates we employed oleoresins from marigold (tagetes erecta l.; lutein diesters), red paprika (capsicum annuum l., mainly capsanthin diesters), papaya (carica papaya l.; beta-cryptoxanthin esters), and loquat (eriobotrya japonica lindl.; beta-cryptoxanthin esters) as well as retinyl palmitate. these were r ... | 2002 | 12128058 |
| hydrolysis of rice bran oil using an immobilized lipase from candida rugosa in isooctane. | the kinetics of enzymatic hydrolysis of rice bran oil in isooctane by immobilized candida rugosa lipase in a batch reactor showed competitive inhibition by isooctane with a dissociation constant, k1, of 0.92 m. continuous hydrolysis of rice bran oil was performed in recycling, packed bed reactor with 4352 u of immobilized lipase; the optimum recycle ratio was 9 and the operational half-life was 360 h without isooctane but 288 h with 25% (v/v) isooctane in rice bran oil. | 2004 | 15168855 |
| enzymatic synthesis of dextran-containing hydrogels. | dextran, a natural glucose-containing polysaccharide, has been acylated by proleather fg-f and lipase ay, a protease and lipase from bacillus sp. and candida rugosa, respectively, in anhydrous dimethylsulfoxide in the presence of vinyl acrylate (va). the efficiency of the reaction in the presence of proleather fg-f and the isolated yields were ca. 71% and 45%, respectively. dextran derivatized with va (dext70-va) was characterized by gel permeation chromatography and its structure was establishe ... | 2002 | 12162328 |
| polyfungal candidaemia due to candida rugosa and candida pelliculosa in a haemodialyzed neonate. | | 2002 | 12195892 |
| detection of simulated candidemia by the bactec 9240 system with plus aerobic/f and anaerobic/f blood culture bottles. | we studied the ability of the bactec 9240 automated blood culture system to detect simulated candidemia, including both candida albicans and non-albicans candida species. simulated blood cultures were produced using 50 candida isolates and bactec plus aerobic/f and anaerobic/f blood culture bottles. ten milliliters of blood and a suspension of each isolate containing 1,000 cfu were introduced into each bottle and then incubated at 35 degrees c in the bactec 9240 system. the system detected growt ... | 2003 | 14532209 |
| immobilization of candida rugosa lipase on chitosan with activation of the hydroxyl groups. | a method for immobilization of candida rugosa lipase to two types of chitosan beads by activating the hydroxyl groups of chitosan using carbodiimide coupling agent has been successfully developed. the ability of carbodiimide to activate the hydroxyl groups of chitosan was confirmed using the electron spectroscopy for chemical analysis (esca) technique. the properties of lipase immobilized using dry and wet chitosan beads were also investigated and compared. immobilization enhanced the enzyme sta ... | 2004 | 14585707 |
| stereochemistry of a diastereoisomeric amphiphile and the species of the lipase influence enzyme activity in the transesterification catalyzed by a lipase-co-lyophilizate with the amphiphile in organic media. | modified candida rugosa and pseudomonas cepacia lipase (crl and pcl) were co-lyophilized with two pairs of synthetic diastereoisomeric amphiphiles, d- and l-2-(3-[bis-[3-(2,3,4,5,6-pentahydroxy-hexanoylamino)-propyl]-carbamoyl]-propionylamino)-pentanedioic acid didodecyl ester (d- and l-big2c12ca); d- and l-2-(2,3,4,5,6-pentahydroxy-hexanoylamino)-pentanedioic acid didodecyl ester (d- and l-2c12ge). enzyme activities of the modified lipase in the transesterification in organic solvent were evalu ... | 2003 | 14677713 |
| immobilization of lipases and assay in continuous fixed bed reactor. | lipases are versatile enzymes regarding the range of reactions they catalyse and substrates on which they act. they are as well important as catalyst in organic synthesis. their immobilization on appropriate supports confer them greater stability besides the possibility of operating in continuous reactors. in order to explore these abilities, the reactions involving hydrolysis of p-nitrophenyl acetate (pnpa) and transesterification of pnpa with n-butanol were chosen. lipases from two different s ... | 2003 | 14683514 |
| immobilization of lipase on chitin and its use in nonconventional biocatalysis. | chitin was functionalized with hexamethylenediamine followed by glutaraldehyde activation, and its capacity to bind candida rugosa lipase was investigated. the loading of 250 units g(-1) support showed to be effective, resulting in a uniform enzyme fixation with high catalytic activity. both free and immobilized lipases were characterized by determining the activity profile as a function of ph, temperature, and thermal stability. for the immobilized lipase, the influence of the reaction temperat ... | 2004 | 14715003 |
| characterisation of steryl esterase activities in commercial lipase preparations. | triglycerides, steryl esters, resin acids, free fatty acids and sterols are lipophilic extractives of wood (commonly referred to as pitch or wood resin) and have a negative impact on paper machine runnability and quality of paper. thus, enzymes capable of modifying these compounds would be potential tools for reducing pitch problems during paper manufacture. in this work, 19 commercial lipase preparations were tested for their ability to degrade steryl esters, which may play a significant role i ... | 2004 | 14741769 |
| immobilization of lipase from candida rugosa on layered double hydroxides for esterification reaction. | synthesis of layered double hydroxides (ldhs) of zn/al-no3- hydrotalcite (hizan) and zn/al-diocytyl sodium sulfosuccinate (dss) nanocomposite (nazad) with a molar ratio of zn/al of 4:1 were carried out by coprecipitation through continuous agitation. their structures were determined using x-ray diffractometer spectra, which showed that basal spacing for ldh synthesized by both methods was about 8.89 a. an expansion of layered structure of about 27.9 a was observed to accommodate the surfactant a ... | 2004 | 15304759 |
| effects of preparative parameters on the properties of chitosan hydrogel beads containing candida rugosa lipase. | the influences of the ph, tripolyphosphate (tpp) concentration, and ionic strength of the gelling medium on the entrapment efficiency, release, and activity of lipase in chitosan hydrogel beads were studied. a solution of candida rugosa lipase was prepared in a 1.5% w/v chitosan and 1% (v/v) acetic acid medium, and dropped into a tpp solution. release of lipase in ph 7.2 tris buffer was monitored over 36 h using the micro bca protein assay. the activity of the entrapped enzyme was assayed using ... | 2004 | 14751751 |
| reactivity of pure candida rugosa lipase isoenzymes (lip1, lip2, and lip3) in aqueous and organic media. influence of the isoenzymatic profile on the lipase performance in organic media. | three pure isoenzymes from candida rugosa lipase (crl: lip1, lip2, and lip3) were compared in terms of their stability and reactivity in both aqueous and organic media. the combined effect of temperature and ph on their stability was studied applying a factorial design. the analysis of the response surfaces indicated that lip1 and lip3 have a similar stability, lower than that of lip2. in aqueous media, lip3 was the most active enzyme on the hydrolysis of p-nitrophenyl esters, whereas lip1 showe ... | 2004 | 14763825 |
| insights from molecular dynamics simulations into ph-dependent enantioselective hydrolysis of ibuprofen esters by candida rugosa lipase. | an interesting observation was found during our continued studies on the hydrolysis of ibuprofen esters by candida rugosa lipase (crl). an important role is played by ph in the stereospecific hydrolysis of these esters. the flap region of crl plays a significant role in the access of the substrate to the active site of the enzyme. at ph 5.6, 48% of the methyl ester and 5% of the butyl ester of ibuprofen were hydrolysed in 5.5 h, whereas at ph 7.2, 9% of methyl ester and 45% of the butyl ester of ... | 2003 | 14983082 |
| preparation of gemini-type amphiphiles bearing cyclitol head groups and their application as high-performance modifiers for lipases. | five gemini-type amphiphiles bearing cyclitol head groups, which have abundance of axial hydroxy groups, are newly synthesized. the syntheses are based on a common mixed anhydride method utilizing n,n'-[iminobis(trimethylene)]bisquinamide, prepared from iminobispropylamine and quino-1,5-lactone, and dialkyl n-(3-carboxypropanoyl)-l-glutamates as polar and hydrophobic components, respectively. candida rugosa lipase (crl) and pseudomonas cepacia lipase (pcl) are co-lyophilized with these synthesiz ... | 2004 | 15013386 |
| [identification of candida albicans using the chromogenic medium albicans id]. | the correct identification of the microrganism is the base for epidemiological studies and treatment of infections. the aim of our study was to evaluate the efficacy of the chromogenic media albicans id (biomerieux, france) in the identification of candida albicans. a total of 190 yeasts strains were evaluated in the study. a rate of 100% of all c. albicans (80) and candida dubliniensis (five) strains exhibited blue color. nevertheless, the blue color was also observed with cultures of candida r ... | 2001 | 15496129 |
| utilizing hydrolases of opposite enantiopreference for the preparation of both enantiomers of (1r,7ar)-(-)- and (1s,7as)-(+)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1h-inden-5(2h)-one. | four racemic esters of (1r*,7ar*)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1h-inden-5(2h)-one were prepared and subjected to hydrolysis with two types of hydrolases, including alcalase and three lipases. alcalase and lipase showed opposite enantiopreference on these esters. based on this result, we developed a gram-scale procedure using butanoate as the substrate, which was treated consecutively with alcalase and lipase from candida rugosa (crl), to give both enantiomers of the title compound in ... | 2004 | 15034910 |
| enantiodivergent preparation of optically active oxindoles having a stereogenic quaternary carbon center at the c3 position via the lipase-catalyzed desymmetrization protocol: effective use of 2-furoates for either enzymatic esterification or hydrolysis. | both enantiomers of oxindoles 2a-h, having a stereogenic quaternary carbon center at the c3 position and a different n-protective group, were readily prepared by the lipase-catalyzed desymmetrization protocol. thus, the transesterification of the prochiral diols 3a-h with 1-ethoxyvinyl 2-furoate 5 was catalyzed by candida rugosa lipase to give (r)-(+)-2a-h (68-99% ee), in which the use of a mixed solvent, (i)pr(2)o (diisopropyl ether)-thf, was crucial. the same lipase also effected the enantiose ... | 2004 | 15049648 |
| activity and enantioselectivity of wildtype and lid mutated candida rugosa lipase isoform 1 in organic solvents. | the activity and enantioselectivity of lipase 1 from candida rugosa and of a chimera enzyme obtained by replacing the lid of isoform 1 with the lid of isoform 3 were compared in organic solvents. the alcoholysis of chloro ethyl 2-hydroxy hexanoate with methanol and of vinyl acetate with 6-methyl-5-hepten-2-ol were used as model reactions in different reaction conditions. the chimera enzyme was less active and enantioselective than the wildtype in all the conditions tested. a rationale for such d ... | 2004 | 15052644 |
| studies on immobilized lipase in hydrophobic sol-gel. | the hydrolysis of tetraethoxysilane using the sol-gel process was used to produce silica matrices, and these were tested for the immobilization of lipase from candida rugosa by three methods: physical adsorption, covalent binding, and gel entrapment in the presence and absence of polyethylene glycol (peg-1450). the silica matrices and their derivatives were characterized regarding particle size distribution, specific surface area, pore size distribution (brunauer, emmett, and teller [b.e.t.] met ... | 2004 | 15054215 |
| characteristics of immobilized lipase on hydrophobic superparamagnetic microspheres to catalyze esterification. | a novel immobilized lipase (from candida rugosa) on hydrophobic and superparamagnetic microspheres was prepared and used as a biocatalyst to catalyze esterification reactions in diverse solvents and reaction systems. the results showed that the immobilized lipase had over 2-fold higher activities in higher log p value solvents. an exponential increase of lipase activity against log p of two miscible solvent mixtures was observed for the first time. both free and immobilized lipase achieved its m ... | 2004 | 15058995 |
| a convenient preparation of 1,2,3-tri-o-acetyl-beta-d-ribofuranose by enzymatic regioselective 5-o-deacetylation of the peracetylated ribofuranose. | the lipase from candida rugosa (sigma) was used to catalyze the regioselective deacetylation at the 5-position of 1,2,3,5-tetra-o-acetyl-beta-d-ribofuranose on a preparative scale. enzymatic deacetylation provides a convenient one-step preparation of 1,2,3-tri-o-acetyl-beta-d-ribofuranose. | 2004 | 15063214 |
| outbreak of candida rugosa candidemia: an emerging pathogen that may be refractory to amphotericin b therapy. | candida rugosa has been rarely reported as a human pathogen. we retrospectively evaluated a cluster of candida rugosa candidemia cases occurring in six hospitalized patients from a tertiary care teaching hospital in são paulo, brazil. genetic relatedness among the six c. rugosa outbreak isolates was characterized by rapd assay using 3 different 10-mer primers and by pulsed field gel electrophoresis. the source of the outbreak was not identified. all patients had been subjected to invasive medica ... | 2003 | 12944016 |
| studies on a novel carbon source and cosolvent for lipase production by candida rugosa. | oleic acid esters were shown to be the best carbon source for both cell growth and lipase production by candida rugosa. use of a cosolvent, dodecane, in fermentations improved the solubility of solid substrates and increased oxygen solubility. this resulted in the highest lipase activity in batch fermentation with glycerol trioleate and dodecane. lipase activity reached 77.1 units ml(-1). | 2004 | 15069604 |
| unexpected reaction profile observed in the synthesis of propyl laurate when using candida rugosa lipases immobilized in microemulsions based organogels. | 1-propyl laurate synthesis should not be used as standard reaction test of immobilized enzymes in microemulsion-based organogels (mbgs) prepared using lecithin/1-propanol as surfactant when extremely active enzymes with high load are used. in these cases, an anomalous kinetic reaction constant value is observed over short reaction times. such an anomalous profile is strongly dependent on the concentration of catalyst in the crude powder and, consequently, is not appreciated when either commercia ... | 2004 | 15604790 |
| integration of purification with immobilization of candida rugosa lipase for kinetic resolution of racemic ketoprofen. | the two processes for the partial purification and for the immobilization of a crude lipase preparation (candida rugosa lipase of) have been successfully integrated into one by simple adsorption of the enzyme onto a cation ion exchanger resin (sp-sephadex c-50) at ph 3.5. due to selective removal of the unfavorable lipase isoenzyme (l1), the enzyme components (mainly l2 and l3) that are tightly fixed on the resin displayed a significantly improved enantioselectivity (e value: 50 versus 13 with a ... | 2004 | 15121339 |
| enzymatic procedures in the preparation of regioprotected d-fructose derivatives. | a combination of different lipases from pseudomonas cepacia, candida antarctica b, candida rugosa and mucor miehei, aided the regioesterification of the free fructose allowing the synthesis of 1,6-di-o-acetyl-d-fructofuranose, 1,4,6-tri-o-acetyl-d-fructofuranose, 1,6-di-o-acetyl-4-o-benzoyl-d-fructofuranose and 1,6-di-o-benzoyl-d-fructofuranose. using c. antarctica b and c. rugosa lipases the alcoholysis of fructose peracetate (alpha, beta-form) has furnished 1,2,3,4-tetra-o-acetyl-alpha-d-fruct ... | 2005 | 15639253 |