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PubMed1998

Functional expression of Rhizopus oryzae lipase in Pichia pastoris: high-level production and some properties.

The mature lipase of the fungus Rhizopus oryzae (ROL) was functionally expressed and secreted in the methylotrophic yeast Pichia pastoris. In a batch cultivation, where methanol feeding was linked to the dissolved oxygen content in the cultivation solution, a lipase activity of 500,000 units per liter (60 mg active lipase per liter) of culture was achieved after initial glycerol feeding of the culture. Recombinant ROL lipase was purified to homogeneity by a simple two-step purification procedure and had a specific activity of 8571 U mg-1 (triolein, 30 degrees C, pH 8.1) which is comparable with the purified native enzyme. The properties of the recombinant lipase were similar to those reported both for the native lipase and for the enzyme expressed in Escherichia coli and refolded from inactive inclusion bodies.

Escherichia coli↗
PubMed1996

Basic fibroblast growth factor-stimulated arachidonic acid release in rat pancreatic acini: sequential action of tyrosine kinase, phospholipase C, protein kinase C and diacylglycerol lipase.

This study was performed to evaluate the effect of human recombinant basic fibroblast growth factor on arachidonic acid release from rat pancreatic acini and to determine the cellular mechanism involved. From enzymatic assays, basic fibroblast growth factor did not significantly stimulate phospholipase A2 activity, whereas it significantly increased diacylglycerol lipase activity. Validity of phospholipase A2 or diacylglycerol lipase inhibitors was confirmed by their ability to inhibit phospholipase A2 or diacylglycerol lipase activities. Basic fibroblast growth factor increased intracellular accumulation and extracellular release of arachidonic acid from metabolically labelled acinar cells in a concentration- and time-dependent manner. This effect was maximal with 50 pM basic fibroblast growth factor and became significant after a 5-min incubation period. The protein tyrosine kinase inhibitor, 0.5 mM genistein, inhibited arachidonic acid release in basic fibroblast growth factor-stimulated acini, whereas 100 microM vanadate, a protein tyrosine phosphatase inhibitor, enhanced arachidonic acid release. Two phospholipase A2 inhibitors, mepacrine and aristolochic acid, failed to attenuate basic fibroblast growth factor-stimulated arachidonic acid release. A diacylglycerol lipase inhibitor RHC 80267 at 150 microM and 50 microM completely inhibited 50 pM basic fibroblast growth factor-induced intracellular accumulation and extracellular release of arachidonic acid, respectively. Furthermore, basic fibroblast growth factor stimulated arachidonic acid release was also inhibited by 10 microM U73122 and by 100 nM staurosporine, phospholipase C and protein kinase C respective inhibitors. Wortmannin, an inhibitor of basic fibroblast growth factor-stimulated phospholipase D, did not affect arachidonic acid release. 100 nM 4 beta-phorbol 12-myristate 13-acetate also increased arachidonic acid release, an effect also inhibited by staurosporine. Taken together, these data demonstrate activation of diacylglycerol lipase and arachidonic acid release in pancreatic acini upon stimulation by basic fibroblast growth factor, and strongly indicate that arachidonic acid release in response to basic fibroblast growth factor depends upon the sequential action of tyrosine kinase, phospholipase C, protein kinase C and diacylglycerol lipase but not from phospholipase A2 not phospholipase D activation.

Animals↗
PubMed1999

Sarcoplasmic lipase and non-specific esterase inhibition in myofibers of rats intoxicated with the organophosphate isofenphos.

The expression of sarcoplasmic esterases, lipases as well as the lipid content in the myofibers of the diaphragm of rats intoxicated with the organophosphate isofenphos was studied. Lipid accumulation was documented at light, electron microsopic and by morphometric studies. The distribution of these lipid droplets was irregular and abundant in myofibers with numerous mitochondria (predominantly oxidative fibers). Histochemical inhibition of sarcoplasmic esterases and lipases was observed in the intoxicated animals. This sarcoplasmic inhibition of esterases occurs roughly in parallel to the inhibition of plasma cholinesterase activity. The inhibition of sarcoplasmic lipases may explain, at least partially, the accumulation of lipids. This inhibition probably makes difficult the use of lipids as fuel, especially in the oxidative fibers. In contrast to the small amount of muscle necrosis, (1.30+/-0.745), metabolic muscle impairment was intense and extensive, i.e., decreased activities of esterases and lipases in the sarcoplasm, that should contribute to muscle weakness. Therefore, because segmental necrosis was most prominent in oxidative fibers (and these fibers use lipids as the principal fuel and contain the greater amount of lipases in the sarcoplasm), it is possible that inhibition of activity of lipases is responsible for the segmental necrosis. Although the exact role of these metabolic changes is not known, it is possible that they contribute not only to the induction and evolution of muscle cell necrosis but also to the muscle weakness and clinical impairment of animals and humans in the acute intoxication by these compounds.

Animals↗
PubMed2001

Effect of culture conditions on lipase production by Fusarium solani in batch fermentation.

Lipase (Glycerol ester hydrolase EC 3.1.1.3.) from a Brazilian strain of Fusarium solani FSI has been investigated. The effect of different carbon sources and trace elements added to basal medium was observed with the aim of improving enzyme production. Lipase specific activity was highest (0.45 U mg(-1)) for sesame oil. When this medium was supplemented with trace elements using olive oil, corn oil and sesame oil the lipase specific activity increased to 0.86, 1.89 and 1.64 U mg(-1), respectively, after 96 h cultivation without any considerable biomass increase. The Km of this lipase using pNPP (p-nitrophenylpalmitate) as substrate, was 1.8 mM with a Vmax of 1.7 micromol min(-1) mg protein(-1). Lipase activity increased in the presence of increasing concentrations of hexane and toluene. In contrast, incubation of this enzyme with water-soluble solvents decreased its activity after 10% concentration (v/v) of the solvent. The lipase activity was stable below 35 degrees C but above this temperature activity losses were observed.

Bioreactors↗
PubMed2002

Production of a Pseudomonas lipase in n-alkane substrate and its isolation using an improved ammonium sulfate precipitation technique.

Among the various lipidic and non-lipidic substances, normal alkanes within the chain lengths of C-12 to C-20 served as the best carbon substrates for the production of extracellular lipase by Pseudomonas species G6. Maximum lipase production of 25 U/ml of the culture broth was obtained by using n-hexadecane as the sole carbon substrate. The optimum pH of 8 and temperature of 34 + 1 degrees C were demonstrated for the production of lipase in n-hexadecane substrate. The optimum concentration of iron, which played a critical role on the lipase production, was found to be 0.25 mg/l. Lipase production could be enhanced to nearly 2.4-fold by using tributyrin at a concentration of 0.05% (v/v) in the culture medium. High recovery of the lipase protein (83%) from the culture broth was achieved by treating the culture supernatant with Silicone 21 Defoamer followed by ammonium sulfate (60% saturation) fractionation.

Alkanes↗
PubMed1998

Structure of a microbial homologue of mammalian platelet-activating factor acetylhydrolases: Streptomyces exfoliatus lipase at 1.9 A resolution.

BACKGROUND: Neutral lipases are ubiquitous and diverse enzymes. The molecular architecture of the structurally characterized lipases is similar, often despite a lack of detectable homology at the sequence level. Some of the microbial lipases are evolutionarily related to physiologically important mammalian enzymes. For example, limited sequence similarities were recently noted for the Streptomyces exfoliatus lipase (SeL) and two mammalian platelet-activating factor acetylhydrolases (PAF-AHs). The determination of the crystal structure of SeL allowed us to explore the structure-function relationships in this novel family of homologous hydrolases. RESULTS: The crystal structure of SeL was determined by multiple isomorphous replacement and refined using data to 1.9 A resolution. The molecule exhibits the canonical tertiary fold of an alpha/beta hydrolase. The putative nucleophilic residue, Ser131, is located within a nucleophilic elbow and is hydrogen bonded to His209, which in turn interacts with Asp177. These three residues create a triad that closely resembles the catalytic triads found in the active sites of other neutral lipases. The mainchain amides of Met132 and Phe63 are perfectly positioned to create an oxyanion hole. Unexpectedly, there are no secondary structure elements that could render the active site inaccessible to solvent, like the lids that are commonly found in neutral lipases. CONCLUSIONS: The crystal structure of SeL reinforces the notion that it is a homologue of the mammalian PAF-AHs. We have used the catalytic triad in SeL to model the active site of the PAF-AHs. Our model is consistent with the site-directed mutagenesis studies of plasma PAF-AH, which implicate Ser273, His351 and Asp296 in the active site. Our study therefore provides direct support for the hypothesis that the plasma and isoform II PAF-AHs are triad-containing alpha/beta hydrolases.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2006

[Immobilization of lipase on macroporous resin and its application in synthesis of biodiesel in low aqueous media].

Lipase from Candida sp. 99-125 was immobilized by physical adsorption onto macroporous resins. The results showed that the nonpolar resin NKA was the best carrier used in low aqueous media. 98.98% of degree of immobilization can be achieved when the adsorption procedure was performed in the presence of heptane. The hydrolytic activity and the apparent activity recovery of lipase adsorbed on resin in heptane was 4.07 and 3.43 times higher than that of lipase adsorbed in sodium phosphate buffer, respectively. The catalytic properties of immobilized lipase for production of biodiesel in low aqueous media were studied. Immobilized lipase displayed the highest activity when the crude enzyme/resin weight ratio was 1.92:1 and the water content(water/oil weight ratio) was 15% at 40 degrees C under pH 7.4. As lipase was adsorbed on NKA in heptane to produce biodiesel, the batch conversion rate can reach 97.3% when a three-step methanolysis protocol was used. After 19 consecutive batches, the conversion rate remained 70.2%.

Candida↗
PubMed2005

Electrochemical method for the detection of lipase activity.

A novel electrochemical technique for the general assay of lipase activity is described. The method utilizes a solid-supported lipase substrate, which is formed by dripping and drying a small amount of an ethanol solution of 9-(5'-ferrocenylpentanoyloxy)nonyl disulfide (FPONDS) onto gold modified by a hexanethiol self-assembled monolayer. The redox ferrocene group of FPONDS generates the electrochemical signal, the intensity of which is proportional to the number of FPONDS molecules at the interface. Electrochemical and surface-enhanced infrared absorption spectroscopic data, as well as control experiments with an engineered, deactivated mutant enzyme, demonstrate that the wild-type lipase from Thermomyces lanuginosus is capable of cleaving the ester bonds of FPONDS molecules via an enzymatic hydrolysis mechanism, which includes the adsorption of the lipase onto the substrate surface. The hydrolysis liberates the ferrocene groups from the interface triggering a decay of the electrochemical redox signal. The rate of the electrochemical signal decrease is proportional to the lipase activity/concentration. These data suggest a general method for the direct measure of enzymatic activity of lipases.

Disulfides↗
PubMed1994

Is lateral phase separation required for fatty acid to stimulate lipases in a phosphatidylcholine interface?

Lipase-catalyzed oxygen exchange between 13,16-cis,cis-docosadienoic acid and water in liquid-expanded monolayers with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine exhibits abrupt, lipid composition-dependent changes in extent and mechanism [e.g., Muderhwa, J. M. and Brockman, H. L. (1992) J. Biol. Chem. 267, 24184-24192]. The critical nature of this transition suggests possible lateral phase separation of the lipids. This has been addressed by substituting for either lipid species one which can exist in more condensed monolayer states. Analysis of phase transition surface pressures as a function of lipid composition shows that each set of fatty acid-phosphatidylcholine mixtures exhibits a finite range of miscibility in liquid-expanded monolayers. These results strongly suggest that 13,16-cis,cis-docosadienoic acid and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine are miscible under the conditions of the oxygen-exchange experiments. Furthermore, to address more directly the relation of lateral lipid phase separation to lipase regulation, oxygen exchange catalyzed by pancreatic carboxylester and triglyceride lipases was studied using mixed monolayers of [18O]2-docosadienoic acid and 1-myristoyl-2-palmitoyl-sn-glycero-3-phosphocholine. These lipids are miscible in the liquid-expanded state at all compositions. The lipid composition dependencies of both the extent and mechanism of lipase-catalyzed oxygen exchange were essentially identical to those obtained earlier. Thus, lateral lipid phase separation is not required for the critical transition in substrate accessibility to lipases. This finding supports a percolation-based model of lipase regulation within a single surface phase and suggests the "topo-temporal" regulation of lipid-mediated signaling in cells.

Chemical Phenomena↗
PubMed2003

Inhibition of dog and human gastric lipases by enantiomeric phosphonate inhibitors: a structure-activity study.

The crystal structures of gastric lipases in the apo form [Roussel, A., et al. (1999) J. Biol. Chem. 274, 16995-17002] or in complex with the (R(P))-undecyl butyl phosphonate [C(11)Y(4)(+)] [Roussel, A., et al. (2002) J. Biol. Chem. 277, 2266-2274] have improved our understanding of the structure-activity relationships of acid lipases. In this report, we have performed a kinetic study with dog and human gastric lipases (DGL and HGL, respectively) using several phosphonate inhibitors by varying the absolute configuration of the phosphorus atom and the chain length of the alkyl/alkoxy substituents. Using the two previously determined structures and that of a new crystal structure obtained with the other (S(P))-phosphonate enantiomer [C(11)Y(4)(-)], we constructed models of phosphonate inhibitors fitting into the active site crevices of DGL and HGL. All inhibitors with a chain length of fewer than 12 carbon atoms were found to be completely buried in the catalytic crevice, whereas longer alkyl/alkoxy chains were found to point out of the cavity. The main stereospecific determinant explaining the stronger inhibition of the S(P) enantiomers is the presence of a hydrogen bond involving the catalytic histidine as found in the DGL-C(11)Y(4)(-) complex. On the basis of these results, we have built a model of the first tetrahedral intermediate corresponding to the tristearoyl-lipase complex. The triglyceride molecule completely fills the active site crevice of DGL, in contrast with what is observed with other lipases such as pancreatic lipases which have a shallower and narrower active site. For substrate hydrolysis, the supply of water molecules to the active site might be achieved through a lateral channel identified in the protein core.

Animals↗
PubMed1997

Pancreatic lipase structure-function relationships by domain exchange.

We designed chimeric mutants by exchanging the lid domains of the classical human pancreatic lipase (HPL) and the guinea pig pancreatic lipase related protein 2 (GPLRP2). This latter enzyme possesses naturally a large deletion within the lid domain and is not activated by lipid/water interfaces. Furthermore, GPLRP2 exhibits phospholipase A1 and lipase activities in the same order of magnitude, whereas HPL has no significant phospholipase activity and displays a clear interfacial activation. An HPL mutant [HPL(-lid)] with GPLRP2 mini-lid domain does not display interfacial activation. Its specific activity toward triglycerides is, however, dramatically reduced. A GPLRP2 mutant [GPLRP2(+lid)] with HPL full-length lid domain is not interfacially activated, and its lid domain probably exists under a permanent open conformation. Therefore, the phenomenon of interfacial activation in HPL is not only due to the presence of a full-length lid domain but also to other structural elements which probably allow the existence of stabilized closed and open conformations of the lid. GPLRP2(+lid) phospholipase activity is significantly reduced as compared to GPLRP2, whereas its lipase activity remains at the same level. Therefore, the lid domain plays a major role in substrate selectivity and can be considered as part of the active site. However, the presence of a full-length lid domain is not sufficient to explain the absence of phospholipase activity in HPL since HPL(-lid) does not display any phospholipase activity. We also produced a chimeric GPLRP2 mutant in which the C-terminal domain was substituted by the HPL C-terminal domain. The colipase effects, i.e., anchoring and stabilization of the lipase at the interface, are clearly observed with the chimera, whereas GPLRP2 is insensitive to colipase. The kinetic characterization of this chimera reveals for the first time that the interfacial stability of pancreatic lipases depends on the structure of the C-terminal domain.

Amino Acid Sequence↗
PubMed1999

Human pancreatic lipase: colipase dependence and interfacial binding of lid domain mutants.

Five key amino acid residues from human pancreatic lipase (HPL) are mutated in some pancreatic lipase-related proteins 2 (PLRP2) that are not reactivated by colipase in the presence of bile salts. One of these residues (Y403) is involved in a direct interaction between the HPL C-terminal domain and colipase. The other four residues (R256, D257, Y267, and K268) are involved in the interactions stabilizing the open conformation of the lid domain, which also interacts with colipase. Here we produced and characterized three HPL mutants: HPL Y403N, an HPL four-site mutant (R256G, D257G, Y267F, and K268E), and an HPL five-site mutant (R256G, D257G, Y267F, K268E, and Y403N), in which the HPL amino acids were replaced by those present in human PLRP2. Colipase reactivated both the HPL Y403N mutant and HPL, and Y403 is therefore not essential for lipase-colipase interactions. Both the HPL four-site and five-site mutants showed low activity on trioctanoin, were inhibited by bile salts (sodium taurodeoxycholate, NaTDC) and were not reactivated by colipase. The interfacial binding of the HPL four-site mutant to a trioctanoin emulsion was suppressed in the presence of 4 mM NaTDC and was not restored by addition of colipase. Protein blotting/protein overlay immunoassay revealed that the HPL four-site mutant-colipase interactions are not abolished, and therefore, the absence of reactivation of the HPL four-site mutant is probably due to a lid domain conformation that prevents the interfacial binding of the lipase-colipase complex. The effects of colipase were also studied with HPL(-lid), an HPL mutant showing an 18-residue deletion within the lid domain, which therefore has only one colipase interaction site. HPL(-lid) showed a low activity on trioctanoin, was inhibited by bile salts, and recovered its lipase activity in the presence of colipase. Reactivation of HPL(-lid) by colipase was associated with a strong interfacial binding of the mutant to a trioctanoin emulsion. The lid domain is therefore not essential for either the interfacial binding of HPL or the lipase-colipase interactions.

Adsorption↗
PubMedDate not supplied

Solid-phase handling of hydrophobins: immobilized hydrophobins as a new tool to study lipases.

Hydrophobins are fungal proteins that self-assemble spontaneously at hydrophilic-hydrophobic interfaces and change the polar nature of the surfaces to which they attach. This attribute can be used to introduce hydrophobic foci on the surface of hydrophilic supports where hydrophobins are attached by covalent binding. In this paper, we report the binding of Pleurotus ostreatus hydrophobins to a hydrophilic matrix (agarose) to construct a support for noncovalent immobilization and activation of lipases from Candida antarctica, Humicola lanuginosa, and Pseudomonas flourescens. Lipase immobilization on agarose-bound hydrophobins proceeded at very low ionic strength and resulted in increased lipase activity and stability. The enzyme could be desorbed from the support using moderate concentrations of Triton X-100, and its enantioselectivity was similar to that of lipases interfacially immobilized on conventional hydrophobic supports. These results suggest that lipase adsorption on hydrophobins follows an "interfacial activation" mechanism; immobilization on hydrophobins offers new possibilities for lipase study and modulation and reveals a new application for fungal hydrophobins.

Candida↗
PubMedDate not supplied

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 could be identified even at enzyme concentrations as high as 1.2 mg/mL in the absence of detergent. It has been stated that bimolecular and monomolecular structures display very different functional properties: (i) the enzyme specific activity decreased when the lipase concentration increased; (ii) the bimolecular form was much more stable than the monomeric one yielding a higher optimal T (increasing between 5 and 10 degrees C) and higher stability in inactivation experiments (the dimer half-life became several orders of magnitude higher than that of the monomer); (iii) the enantioselectivity depended on the enzyme concentration even after immobilization. For example, with use of the lipase from H. lanuginosa, the enantiomeric excess of the remaining ester in the hydrolysis of fully soluble ethyl ester of (R,S)-2-hydroxy-4-phenylbutanoic acid varied from 4 to 57 when the concentrated or diluted enzyme immobilized on PEI support, respectively, was used. It seems that the bimolecular structure of lipases might be formed by two open lipase molecules (interfacially activating each other) in very close contact and hence with a very altered active center.

Ascomycota↗
PubMedDate not supplied

Comparative fatty acid selectivity of lipases in esterification reactions with glycerol and diol analogues in organic media.

Reaction selectivity of Pseudomonas cepacia, Rhizomucor miehei, and Candida antarctica B lipases was assessed in multicompetitive esterification reaction mixtures containing an homologous series of n-chain even carbon number fatty acid (FA; C4-C18) substrates and a single alcohol cosubstrate (glycerol, 1,2-propanediol (1,2-PD), or 1, 3-propanediol (1,3-PD)) in tert-butyl methyl ether at water activity of 0.69 or 0.90 and a reaction temperature of 35 degrees C. For P. cepacia lipase, the ordinal patterns of FA selectivities observed were, with glycerol, C8 > C10, C6, C16 > other FA; with 1,2-PD and 1, 3-PD, C16 > C8 > C14 > other FA. For R. miehei lipase, the ordinal patterns of FA selectivities observed were, with glycerol, C8 > C12 > C10, C14 > other FA; with 1,2-PD and 1,3-PD, C8 > C12 > other FA. For C. antarctica B lipase, the ordinal patterns of FA selectivities observed were, with glycerol, C8 > C10, C6, C12 > other FA; with 1, 2-PD, C8 > C10, C6 > other FA; and with 1,3-PD, C8 > C10 > C6 > other FA. The differences in selectivity among FA ranged up to 16-fold, depending upon the lipase and alcohol cosubstrate used. These findings represent intrinsic and substrate-modulated features of FA selectivities that are of particular relevance to the use of lipases for acylglycerol synthesis reactions.

Burkholderia cepacia↗
PubMedDate not supplied

Lipase-catalyzed cellulose acetylation in aqueous and organic media.

Screening for lipases capable of catalyzing acetylation of cellulosic substrates was conducted in aqueous buffer solution using water-soluble carboxymethyl cellulose (CMC) as substrate. Lipase A12 from Aspergillus niger (A. niger) showed the most promising acetylation activity among 11 tested commercial microbial lipases and was further applied to catalyzing acetylation of solid cellulose in aqueous solution. This reaction was shown to be feasible with an acetylation extent of 0.16 wt % achieved compared with no detectable acetylation in the absence of enzyme. Pretreatments on cellulose substrate by ultrasonic irradiation and surfactant solution only slightly improved the acetylation extent by 44 and 27%, respectively. Alternatively, this lipase-catalyzed acetylation was remarkably improved with solubilized cellulose as substrate in the dimethyl sulfoxide/paraformaldehyde solvent system, with an acetylation extent (7.87 wt %) nearly 50 times higher than that achieved in aqueous solution. This improvement was attributed to (1) the absence of bulk water and the increase in substrate solubility by the transition of reaction media from aqueous solution to organic solvents and (2) the ability of lipase A12 to remain catalytically active in highly polar DMSO. This discovery that the A. niger lipase was capable of surviving its contact with polar solvents was further confirmed by its considerably preserved catalytic activity on CMC acetylation in aqueous media after enzyme pretreatments with organic solvents of various polarities and in mixture media with the aqueous phase partially replaced by organic solvents.

Acetylation↗
PubMed2004

Model studies on the formation of monochloropropanediols in the presence of lipase.

The formation of chloropropanols was investigated using model systems comprised of lipase, vegetable oil or fat, water, and sodium chloride. The results showed that measurable levels of the foodborne carcinogen 3-chloro-1,2-propanediol (3-MCPD) are formed in the presence of commercially available lipases of mammalian, vegetable, and fungal origins, incubated at temperatures of 40 degrees C. The highest yield of 3-MCPD was obtained in reaction mixtures containing lipase from Rhizopus oryzae, and all the lipases studied exhibited a high hydrolytic activity toward triglycerides from palm and peanut oil. In contrast, hydrolysis over time and the yield of 3-MCPD in olive and sunflower oils were significantly lower (up to 10-fold), possibly linked to the relatively lower amount (<18%) of saturated fatty acids in these oils. We provide here for the first time evidence that lipases are able to induce the formation of chloropropanols under model system conditions. However, the key intermediates and precise mechanistic aspects governing the formation of 3-MCPD in the presence of lipase still need to be elucidated.

Hydrogen-Ion Concentration↗
PubMed2006

Highly efficient preparation of lipophilic hydroxycinnamates by solvent-free lipase-catalyzed transesterification.

Various medium- or long-chain alkyl cinnamates and hydroxycinnamates, including oleyl p-coumarate as well as palmityl and oleyl ferulates, were prepared in high yield by lipase-catalyzed transesterification of an equimolar mixture of a short-chain alkyl cinnamate and a fatty alcohol such as lauryl, palmityl, and oleyl alcohol under partial vacuum at moderate temperature in the absence of solvents and drying agents in direct contact with the reaction mixture. Immobilized lipase B from Candida antarctica was the most effective biocatalyst for the various transesterification reactions. Transesterification activity of this enzyme was up to 56-fold higher than esterification activity for the preparation of medium- and long-chain alkyl ferulates. The relative transesterification activities found for C. antarctica lipase were of the following order: hydrocinnamate > cinnamate > 4-hydroxyhydrocinnamate > 3-methoxycinnamate > 2-methoxycinnamate approximately 4-methoxycinnamate approximately 3-hydroxycinnamate > hydrocaffeate approximately 4-hydroxycinnamate > ferulate > 2-hydroxycinnamate > caffeate approximately sinapate. With respect to the position of the hydroxy substituents at the phenyl moiety, the transesterification activity of C. antarctica lipase B increased in the order meta > para > ortho. The immobilized lipases from Rhizomucor miehei and Thermomyces lanuginosus demonstrated moderate and low transesterification activity, respectively. Compounds with inverse chemical structure, that is, 3-phenylpropyl alkanoates such as 3-(4-hydroxyphenyl)propyl oleate and 3-(3,4-dimethoxyphenyl)propyl oleate, were obtained by C. antarctica lipase-catalyzed transesterification of fatty acid methyl esters with the corresponding 3-phenylpropan-1-ols in high yield, as well.

Ascomycota↗