Enzymatic production of bioactive docosahexaenoic acid phenolic ester

Enzymatic synthesis of vanillyl fatty acid esters from salmon oil in a solvent-free medium

This study hypothesizes that the solvent-free alcoholysis of oil recovered from salmon heads using vanillyl alcohol (VA) and immobilized lipase B can efficiently produce esters with enhanced stability and antioxidant properties. The objective was to investigate the selectivity and resulting ester profile, which may provide nutritional and functional advantages compared to supplementing oil with vanillyl alcohol. After 24 h, nearly complete conversion of vanillyl alcohol was achieved, leading to the production of various esters reflective of the oil's original fatty acid composition. The synthesis of esters like oleoyl and linolenoyl was favored over docosahexaenoyl and linoleoyl esters, influenced by fatty acid distribution and enzyme specificity, along with potential intra-molecular acyl transfer isomerization. The reaction medium demonstrated significant stability and antioxidant activity, highlighting the potential benefits of vanillyl esters over traditional supplementation methods. These findings suggest that the phenolic alcohol-based alcoholysis of fish oil offers a promising approach to generating stable, nutritionally valuable extracts with potent antioxidant capabilities.

Long chain capsaicin analogues synthetized by CALB-CLEAs show cytotoxicity on glioblastoma cell lines

Glioblastoma is one of the most lethal tumors, displaying striking cellular heterogeneity and drug resistance. The prognosis of patients suffering from glioblastoma after 5 years is only 5%. In the present work, capsaicin analogues bearing modifications on the acyl chain with long-chain fatty acids showed promising anti-tumoral activity by its cytotoxicity on U-87 and U-138 glioblastoma multiforme cells. The capsaicin analogues were enzymatically synthetized with cross-linked enzyme aggregates of lipase B from Candida antarctica (CALB). The catalytic performance of recombinant CALB-CLEAs was compared to their immobilized form on a hydrophobic support. After 72 h of reaction, the synthesis of capsaicin analogues from linoleic acid, docosahexaenoic acid, and punicic acid achieved a maximum conversion of 69.7, 8.3 and 30.3% with CALB-CLEAs, respectively. Similar values were obtained with commercial CALB, with conversion yields of 58.3, 24.2 and 22% for capsaicin analogues from linoleic acid, DHA and punicic acid, respectively. Olvanil and dohevanil had a significant cytotoxic effect on both U-87 and U-138 glioblastoma cells. Irrespective of the immobilization form, CALB is an efficient biocatalyst for the synthesis of anti-tumoral capsaicin derivatives. KEY POINTS: • This is the first report concerning the enzymatic synthesis of capsaicin analogues from docosahexaenoic acid and punicic acid with CALB-CLEAs. • The viability U-87 and U-138 glioblastoma cells was significantly affected after incubation with olvanil and dohevanil. • Capsaicin analogues from fatty acids obtained by CALB-CLEAs are promising candidates for therapeutic use as cytotoxic agents in glioblastoma cancer cells.

Solvent-free enzymatic synthesis and evaluation of vanillyl propionate as an effective and biocompatible preservative

Preservatives are chemicals added to protect products against microbial spoilage, and thus are indispensable for pharmaceuticals, cosmetics, and foods. Due to growing concerns about human health and environments in conventional chemical preservatives, many companies have been seeking safe and effective alternatives that can be produced through environment-friendly processes. In this work, in order to develop effective and safe preservatives from plants, we attempt solvent-free lipase-catalyzed transesterification of vanillyl alcohol with ethyl propionate for the first time. The reaction product, vanillyl propionate was efficiently obtained in a high yield. Unlike vanillyl alcohol and ethyl propionate, vanillyl propionate showed antimicrobial activity. The minimal inhibitory concentration test showed that it exhibited high and broad antimicrobial activity against all the tested microorganisms (Gram-negative and Gram-positive bacteria, yeasts, and molds), which was overall comparable to that of propyl paraben, which is one of the most effective preservatives. It was also found to have even higher antioxidant capacity and biocompatibility with human cells than propyl paraben. Vanillyl propionate, which is a plant-based preservative produced through a green bioprocess, is expected to be successfully applied to various industries thanks to its high antimicrobial and antioxidant effect, and high biocompatibility.

Enzymatic Modification of Pomace Olive Oil with Natural Antioxidants: Effect on Oxidative Stability

Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive oil (POO) in solvent-free conditions using immobilized lipase on biogenic nanoparticles. The effect of temperature (30-70 °C) and enzyme concentration (0.1-1%, w/w) on the efficiency of the bioprocess as well as the reusability of the nanobiocatalyst were thoroughly investigated. The modified oils exhibited increased antioxidant activity compared to the control oil according to DPPH and CUPRAC assays (p < 0.05). The oxidative stability of pomace olive oil was also significantly enhanced after modification, as depicted by the K₂₃₂ values and TBARS contents under accelerated oxidation at 60 °C (p < 0.05). Moreover, a fortified mayonnaise containing modified oil with HTYR was prepared that was noticeably stable compared to the control mayonnaise at 28 °C for 5 months (p < 0.05). Enzymatically modified oils have great potential for application in the nutraceutical and food industry, encouraging the exploitation of immobilized lipases as effective and green catalytic tools.

Enzymatic lipophilization of bioactive compounds with high antioxidant activity: a review

Food products contain bioactive compounds such as phenolic and polyphenolic compounds and vitamins, resulting in a myriad of biological characteristics such as antimicrobial, anticarcinogenic, and antioxidant activities. However, their application is often restricted because of their relatively low solubility and stability in emulsions and oil-based products. Therefore, chemical, enzymatic, or chemoenzymatic lipophilization of these compounds can be achieved by grafting a non-polar moiety onto their polar structures. Among different methods, enzymatic modification is considered environmentally friendly and may require only minor downstream processing and purification steps. In recent years, different systems have been suggested to design the synthetic reaction of these novel products. This review presents the new trends in this area by summarizing the essential enzymatic modifications in the last decade that led to the synthesis of bioactive compounds with attractive antioxidative properties for the food industry by emphasizing on optimization of the reaction conditions to maximize the production yields. Lastly, recent developments regarding characterization, potential applications, emerging research areas, and needs are highlighted.

Structural Modifications of a Flaxseed Lignan in Pursuit of Higher Liposolubility: Evaluation of the Antioxidant and Permeability Properties of the Resulting Derivatives

While lignans and their biogenetic precursors can have various health benefits, the poor liposolubilities of such phenolic systems have restricted their application as antioxidants in the food industry. The research reported here was aimed at addressing these matters through derivatizing certain forms of such compounds and then assessing their properties as potential nutraceuticals. In particular, crude flaxseed lignan was purified to afford secoisolariciresinol diglucoside (SDG, 1) that was then subjected to structural modification. By such means, the SDG long-chain fatty acid esters 4-9 and 11-13, the fully acetylated SDG 10, secoisolariciresinol (SECO, 2), and anhydrosecoisolariciresinol (ASECO, 14) were obtained. The antioxidant activities of these derivatives were determined while their permeability properties were evaluated. Such studies revealed that certain SDG derivatives possessing useful liposolubilities also retained their antioxidative properties, as well as being capable of permeating Caco-2 cell monolayers while being nontoxic to them. SDG fatty acid esters 4-9 and 11-13 could be developed into emulsifiers with enhanced health benefits, especially considering their improved antioxidative (ca. <11 000 μmol Trolox/g) and permeability properties. This study thus highlights strategies for the structural modification of SDG so as to generate derivatives with superior properties in terms of their utility in the food and pharmaceutical industries.

From batch to fed-batch and to continuous packed-bed reactors: Lipase-catalyzed esterifications in low viscous deep-eutectic-solvents with buffer as cosolvent

This work explores for the first time the use of Deep Eutectic Solvents (DES) with phosphate buffer 100 mM pH 7 as cosolvent (10% v/v) in biocatalytic reactions in fed-batch and packed-bed bioreactors. The lipase-catalyzed esterification of glycerol and benzoic acid is studied, as it involves two substrates with different polarities (for which DES are needed). In the fed-batch bioreactor, the highest conversion (90%) was obtained at a substrate flow rate of 0.01 mL/min. The fed-batch operation increased the conversion by 59% compared to the batch mode. Regarding productivity, semi-continuous and continuous bioreactors showed analogous results. Upon recirculation of the reaction media in the continuous bioreactor, a conversion of 67% was achieved in 7 cycles of operation. The stability of the biocatalyst in the packed-bed bioreactor decreased only 2% in 10 days, demonstrating the attractiveness that low viscous DES-water mixtures with continuous processes may have.

Synthesis of Feruloyl Ester Using Bacillus subtilis AKL 13 Lipase Immobilized on Celite® 545

The lipophilic antioxidants, glyceryl ferulate and feruloyl glyceryl linoleate, were synthesized using lipase from Bacillus subtilis AKL 13. The extracellular lipase was produced by cultivation of the strain in modified minimal medium and the enzyme was recovered by fractionation at 80% ammonium salt saturation. The concentrated enzyme with the specific activity of (4647±66) U/mg was immobilized on Celite® 545 and crosslinked using glutaraldehyde. The prepared enzyme catalyst was used for esterification of ferulic and linoleic acids with glycerol separately in hexane butane solvent system at 50 °C and 3.144×g agitation. The maximum ester conversion of 94% of feruloyl glyceryl linoleate was achieved at 48 h, whereas only 35% of glyceryl ferulate was synthesized. The reaction products were characterized using RP-HPLC, FTIR, ¹H NMR, ¹³C NMR and fluorescence spectrophotometry. The kinetic parameters of esterification reaction were determined according to ping-pong bi-bi model. The K_m and υ_max were found to be 69.37 and 3.46 mmol, and 0.387 and 1.02 mmol/(min·g) for glyceryl ferulate and feruloyl glyceryl linoleate, respectively. The kinetic parameters were simulated in MATLAB and the experimental data were in good agreement. Furthermore, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of the blend of feruloyl ester and palm oil was higher than of the plain palm oil and was closer to α-tocopherol.

Synthesis and in vitro antioxidant and antimicrobial studies of novel structured phosphatidylcholines with phenolic acids

Novel phenoylated phosphatidylcholines were synthesized from 1,2-dipalmitoyl phosphatidylcholine/egg 1,2-diacyl phosphatidylcholine and phenolic acids such as ferulic, sinapic, vanillic and syringic acids. The structures of phenoylated phosphatidylcholines were confirmed by spectral analysis. 2-acyl-1-lyso phosphatidylcholine was synthesized from phosphatidylcholine via regioselective enzymatic hydrolysis and was reacted with hydroxyl protected phenolic acids to produce corresponding phenoylated phosphatidylcholines in 48-56% yields. Deprotection of protected phenoylated phosphatidylcholines resulted in phenoylated phosphatidylcholines in 87-94% yields. The prepared compounds were evaluated for their preliminary in vitro antimicrobial and antioxidant activities. Among the active derivatives, compound 1-(4-hydroxy-3,5-dimethoxy) cinnamoyl-2-acyl-sn-glycero-3-phosphocholine exhibited excellent antioxidant activity with EC₅₀ value of 16.43μg/mL. Compounds 1-(4-hydroxy-3-methoxy) cinnamoyl-2-acyl-sn-glycero-3-phosphocholine and 1-(4-hydroxy-3,5-dimethoxy) cinnamoyl-2-palmitoyl-sn-glycero-3-phosphocholine exhibited good antioxidant activity with EC₅₀ values of 36.05 and 33.35μg/mL respectively. Compound 1-(4-hydroxy-3-methoxy) cinnamoyl-2-palmitoyl-sn-glycero-3-phosphocholine exhibited good antibacterial activity against Klebsiella planticola with MIC of 15.6μg/mL and compound 1-(4-hydroxy-3-methoxy) benzoyl-2-acyl-sn-glycero-3-phosphocholine exhibited good antifungal activity against Candida albicans with MIC of 15.6μg/mL.

Synthesis of biosafe isosorbide dicaprylate ester plasticizer by lipase in a solvent-free system and its sub-chronic toxicity in mice

The biosafety isosorbide dicaprylate ester plasticizer was synthesized with bubbling dried air in solvent-free system.