Lipase-catalysed ammoniolysis of lipids. A facile synthesis of fatty acid amides

Fatty Acid Amides Synthesized from Andiroba Oil (Carapa guianensis Aublet.) Exhibit Anticonvulsant Action with Modulation on GABA-A Receptor in Mice: A Putative Therapeutic Option

Epilepsy is a chronic neurological disease characterized by excessive neuronal activity leading to seizure; about 30% of affected patients suffer from the refractory and pharmacoresistant form of the disease. The anticonvulsant drugs currently used for seizure control are associated with adverse reactions, making it important to search for more effective drugs with fewer adverse reactions. There is increasing evidence that endocannabinoids can pharmacologically modulate action against seizure and antiepileptic disorders. Therefore, the objective of this study is to investigate the anticonvulsant effects of fatty acid amides (FAAs) in a pentylenetetrazole (PTZ)-induced seizure model in mice. FAAs (FAA1 and FAA2) are obtained from Carapa guianensis oil by biocatalysis and are characterized by Fourier Transform Infrared Analysis (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS). Only FAA1 is effective in controlling the increased latency time of the first myoclonic jerk and in significantly decreasing the total duration of tonic-clonic seizures relative to the pentylenetetrazol model. Also, electrocortical alterations produced by pentylenetetrazol are reduced when treated by FAA1 that subsequently decreased wave amplitude and energy in Beta rhythm. The anticonvulsant effects of FAA1 are reversed by flumazenil, a benzodiazepine antagonist on Gamma-Aminobutyric Acid-A (GABA-A) receptors, indicating a mode of action via the benzodiazepine site of these receptors. To conclude, the FAA obtained from C. guianensis oil is promising against PTZ-induced seizures.

Selective Transformations of Triglycerides into Fatty Amines, Amides, and Nitriles by using Heterogeneous Catalysis

The use of triglycerides as an important class of biomass is an effective strategy to realize a more sustainable society. Herein, three heterogeneous catalytic methods are reported for the selective one-pot transformation of triglycerides into value-added chemicals: i) the reductive amination of triglycerides into fatty amines with aqueous NH₃ under H₂ promoted by ZrO₂ -supported Pt clusters; ii) the amidation of triglycerides under gaseous NH₃ catalyzed by high-silica H-beta (Hβ) zeolite at 180 °C; iii) the Hβ-promoted synthesis of nitriles from triglycerides and gaseous NH₃ at 220 °C. These methods are widely applicable to the transformation of various triglycerides (C₄ -C₁₈ skeletons) into the corresponding amines, amides, and nitriles.

Novozym 435: the “perfect” lipase immobilized biocatalyst?

Novozym 435 (N435) is a commercially available immobilized lipase produced by Novozymes with its advantages and drawbacks.

Macroporous Beads for Lipase Immobilization

Lipase isolated from Arthrobacter sp. (RRLJ-1, MTCC No. 5125, named ABL), is effective in resolving a wide range of racemic drug intermediates. In this study, ABL was immobilized on a series of synthetic macroporous epoxy copolymers beads with varying pore sizes, surface area and hydrophobicity. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads, with 75% crosslink density and 10% of epoxy groups modified with dibutyl amine [GMA-EGDM-75 (10% DBA)] had a pore volume of 0.77 mL/g and a surface area of 86.05 m 2/g; these beads were optimally suitable for ABL immobilization. The covalent binding of the lipase was optimized by varying the ionic strength, buffers, pH, temperature and time. The optimal binding was achieved in 100 mM phosphate buffer at 4°C, pH 7.0 in three hours. Under these conditions the polymer retained 34 units and 12 mg of ABL per gram. Immobilized ABL displayed enhanced thermal, organic solvent and pH stability compared to the free enzyme. The immobilized enzyme was used repeatedly (fifteen cycles) to resolve the fluoxitine intermediate (racemic ethyl-3-hydroxy-3-phenyl propanoate) without any loss in stereospecificity. The resolution time of fluoxitine intermediate was reduced to almost half (from 84 to 48 hours) by using the immobilized enzyme.

Aminolysis of triglycerides using nanocrystalline nickel doped CaO as an efficient solid catalyst

A Ni/CaO catalyst is able to catalyze (A) aminolysis as well as (B) transesterification reactions.

Solvent-free one step aminolysis and alcoholysis of low-quality triglycerides using sodium modified CaO nanoparticles as a solid catalyst

Aminolysis of used cotton seed oil derived fatty acid methyl ester (FAMEs).

One step synthesis of fatty acid diethanolamides and methyl esters from triglycerides using sodium doped calcium hydroxide as a nanocrystalline heterogeneous catalyst

A recyclable heterogeneous catalyst based direct aminolysis of vegetable oils.

Enzymatic synthesis of fatty amides from palm olein

Fatty amides have been successfully synthesized from palm olein and urea by a one-step lipase catalyzed reaction. The use of immobilized lipase as the catalyst for the preparation reaction provides an easy isolation of the enzyme from the products and other components in the reaction mixture. The fatty amides were characterized using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance ((1)H NMR) technique and elemental analysis. The highest conversion percentage (96%) was obtained when the process was carried out for 36 hours using urea to palm oil ratio of 5.2: 1.0 at 40 degrees C. The method employed offers several advantages such as renewable and abundant of the raw material, simple reaction procedure, environmentally friendly process and high yield of the product.

Lipase-catalyzed production of a bioactive fatty amide derivative of 7,10-dihydroxy-8(E)-octadecenoic acid

Enzymatic syntheses of fatty amides are of considerable interest due to their wide ranging industrial applications in detergents, shampoo, cosmetics and surfactant formulations. Amidation reaction of Candida antarctica lipase B (CALB) was investigated for direct amidation of carboxylic acid in organic solvent. CALB-mediated production of a novel secondary amide was carried out by reacting the hydroxy oleic acid derivative, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), with N-methylethanol amine in organic solvent medium. A single, new product peak corresponding to the secondary amide of DOD (D2AM) was detected by high-performance liquid chromatography and thin-layer chromatography. The production of D2AM was achieved in high yields (95%) after 72 h at 50 degrees C in a CALB-catalyzed reaction that contained 100 IU enzyme activity, 50 mM DOD, and 100 mM N-methylethanol amine in isoamyl alcohol. The new fatty amide D2AM displayed potent antimicrobial activity towards Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Proteus vulgaris and Klebsiella pneumonae). D2AM also exhibited antioxidative activity by its alpha,alpha-diphenyl-beta-picryl-hydrazyl (DPPH) radicals scavenging effects.

The complications of promiscuity: endocannabinoid action and metabolism

In this review, we present our understanding of the action and metabolism of endocannabinoids and related endogenous molecules. It is clear that the interactions between the multiple endocannabinoid-like molecules (ECLs) are highly complex, both at the level of signal transduction and metabolism. Thus, ECLs are a group of ligands active at 7-transmembrane and nuclear receptors, as well as transmitter-gated and ion channels. ECLs and their metabolites can converge on common endpoints (either metabolic or signalling) through contradictory or reinforcing pathways. We highlight the complexity of the endocannabinoid system, based on the promiscuous nature of ECLs and their metabolites, as well as the synthetic modulators of the endocannabinoid system.

Highly Selective Enzymatic Kinetic Resolution of Primary Amines at 80 °C: A Comparative Study of Carboxylic Acids and Their Ethyl Esters as Acyl Donors

Optimization of the kinetic resolution of 2-amino-4-phenyl-butane was achieved at 80 degrees C using CAL-B-catalyzed aminolysis of carboxylic acids and their ethyl esters. The reactions carried out with long chain esters and the corresponding acids as acyl donors proceeded with remarkably high enantioselectivity. The use of carboxylic acids as acylating agents led to a marked acceleration of the reaction rate compared to their ester counterparts. Lauric acid led to enantiomeric excesses superior to 99.5% for both the remaining amine and the corresponding lauramide at 50% conversion (reached in 3 h). These optimized conditions were applied to the resolution of a series of aliphatic and benzylic amines.

Purification, immobilization, and stabilization of a lipase from Bacillus thermocatenulatus by interfacial adsorption on hydrophobic supports

A lipase from Bacillus thermocatenulatus (BTL2) cloned in E. coli has been purified using a very simple method: interfacial activation on a hydrophobic support followed by desorption with Triton. Only one band was detected by SDS-PAGE. The pure enzyme was immobilized using different methodologies. BTL2 adsorbed on a hydrophobic support (octadecyl-Sepabeads) exhibited a hyperactivation with respect to the soluble enzyme, whereas the other immobilized preparations suffered a slight decrease in the expressed activity. The soluble enzyme was very stable, but all immobilized preparations were much more stable than the soluble enzyme, the octadecyl-Sepabeads-BTL2 preparation being the most stable one in all conditions (high temperature or in the presence of organic cosolvents), maintaining 100% of the activity at 65 degrees C or 30% of dioxane and 45 degrees C after several days of incubation. The glyoxyl preparation, the second more stable, retained 80% of the initial activity after 2 days, respectively. The adsorption of this thermophilic lipase on octadecyl-Sepabeads permitted an increase in the optimal temperature of the enzyme of 10 degrees C.

Lipase and esterase-catalyzed acylation of hetero-substituted nitrogen nucleophiles in water and organic solvents

The lipase- and esterase-catalyzed acylations of hydroxylamine and hydrazine derivatives with octanoic acid and ethyl octanoate are described. The influence of solvent and nucleophile on the initial reaction rate was investigated for a number of free and immobilized enzymes. Initial rates were highest in water, but the overall productivity was optimal in dioxane. Octanoic acid (250 g/L) was converted for 93% into the hydroxamic acid in 36 h with only 1% (w/w) Candida antarctica lipase B (Novozym 435) in dioxane at 40 degrees C. This translates to a catalyst productivity of 68.5 g. g(-1). day(-1) and a space time yield of 149 g. L(-1). day(-1), unprecedented figures in the direct reaction of an acid with a nitrogen nucleophile in an organic solvent.

A single step purification, immobilization, and hyperactivation of lipases via interfacial adsorption on strongly hydrophobic supports

A number of bacterial lipases can be immobilized in a rapid and strong fashion on octyl-agarose gels (e.g., lipases from Candida antarctica, Pseudomonas fluorescens, Rhizomucor miehei, Humicola lanuginosa, Mucor javanicus, and Rhizopus niveus). Adsorption rates in absence of ammonium sulfate are higher than in its presence, opposite to the observation for typical hydrophobic adsorption of proteins. At 10 mM phosphate, adsorption of lipases is fairly selective allowing enzyme purification associated with their reversible immobilization. Interestingly, these immobilized lipase molecules show a dramatic hyperactivation. For example, lipases from R. niveus, M. miehei, and H. lanuginosa were 6-, 7-, and 20-fold more active than the corresponding soluble enzymes when catalyzing the hydrolysis of a fully soluble substrate (0.4 mM p-nitrophenyl propionate). Even higher hyperactivations and interesting changes in stereospecificity were also observed for the hydrolysis of larger soluble chiral esters (e.g. (R,S)-2-hydroxy-4-phenylbutanoic ethyl ester). These results suggest that lipases recognize these "well-defined" hydrophobic supports as solid interfaces and they become adsorbed through the external areas of the large hydrophobic active centers of their "open and hyperactivated structure". This selective interfacial adsorption of lipases becomes a very promising immobilization method with general application for most lipases. Through this method, we are able to combine, via a single and easily performed adsorption step, the purification, the strong immobilization, and a dramatic hyperactivation of lipases acting in the absence of additional interfaces, (e.g., in aqueous medium with soluble substrate). Copyright 1998 John Wiley & Sons, Inc.

Immobilization of lipases by selective adsorption on hydrophobic supports

The preparation of immobilized derivatives of lipases that may be useful to develop industrial processes of organic synthesis is an exciting field of research in which three main features have to be simultaneously considered: (a) immobilized derivatives have to be compatible with very different reaction requirements (e.g. continuous adjustment of pH with concentrated alkali, use of aqueous media or organic solvents, etc.); (b) Sometimes, some activity/stability properties of lipases should be improved during immobilization; and (c) because of a complex mechanism of action, lipases are poorly active in the absence of hydrophobic interfaces. In this paper, we will review different approaches for lipase immobilization mainly related to the further use of immobilized derivatives to carry out enantio and regioselective hydrolysis in high water-activity systems. Special emphasis is paid to the selective adsorption of lipases on tailor-made strongly hydrophobic support surfaces. This new immobilization procedure is based on the assumption that the large hydrophobic area that surrounds the active site of lipases is the one mainly involved in their adsorption on strongly hydrophobic solid surfaces. Thus, lipases recognize these surfaces similarly to those of their natural substrates and they suffer interfacial activation during immobilization. This immobilization method permits: (a) promote a dramatic hyper-activation of most of lipases after their immobilization. That is, adsorbed lipases show very enhanced esterase activity in the absence of additional hydrophobic interfaces; (b) promote highly selective adsorption of lipases, at very low ionic strength, from impure protein extracts. That is, we can associate immobilization and purification of lipases; (c) promote interesting improvements of enantioselectivity after immobilization; and (d) promote a strong but reversible immobilization that enables us to recover these expensive supports after inactivation of immobilized lipases.