Oxidation of Triacyiglycerol by Laccase-Mediator Systems.

Saba, Hayato; Nakano, Masuo

doi:10.5650/jos.52.15

Cited by 3 publications

(8 citation statements)

References 15 publications

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“…On the SEC elution curve of oxidized fatty acids showing lower and higher molecular weight portion formations, the former portion is considered as a degradation product of the corresponding peroxidized unsaturated fatty acid (16). The oxidized products of the fatty acids such as linolenic acid and linoleic acid that are oxidized by the present laccase/natural mediator and laccase/mediator derived from natural compounds systems showed the same result (data not shown).…”

Section: Oxidation Of Triacylglycerol By Laccase-natural Mediatormentioning

confidence: 67%

“…2,4-Dimethoxyphenol (DMP), syringic alcohol (SAlc), syringaldehyde (SAld), syringic acid (SAcid) and transferulic acid (FAcid) can be obtained from the lignin in wood. ABTS and HBT were used as typical synthetic mediators, because they have been reported as high performance mediators in many papers (2,(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)21,22). The results of the oxidation of LO by various reaction systems are shown in Fig.…”

Section: Results and Discussion 1 Effect Of Mediatormentioning

confidence: 99%

“…The reactions were carried out using two times of the volume used in a previously described method (16). The triacylglycerol (TG) (1.4 M, based on a fatty acid residual group) or fatty acid (1.4 M), 0.242 mL of 0.05 M acetate buffer (pH 4.1), Tween20 (0.5 wt%) and mediator (0.07 M) were put in a screw-capped 15 mm diameter test tube, and then 0.1 mL of laccase solution in water (18.8 units, 0.226 mg of protein) was quickly added, then immediately stirred using a magnetic stirrer in a 40 water bath under air.…”

Section: Oxidation Reactionmentioning

confidence: 99%

“…Quantitative analysis of the composition of the fatty acid in TG, that of the peroxide in the oxidized TG and fatty acids using the modified ferric thiocyanate method, and the oxidation index were determined as previously described (16). Size exclusion chromatography (SEC) analysis and a gas chromatography/mass spectrometry (GC/MS) analysis were also done using previously described methods (16).…”

Section: Measurementsmentioning

confidence: 99%

“…Size exclusion chromatography (SEC) analysis and a gas chromatography/mass spectrometry (GC/MS) analysis were also done using previously described methods (16). The oxidation potential of the mediators was determined using cyclic voltammograms (CV), which were obtained with a BAS CV-50W Voltammetric Analyzer (Indiana, USA).…”

Section: Measurementsmentioning

confidence: 99%

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Oxidation of Triacyiglycerol by Laccase-Natural Mediator and Laccase-Mediator Derived from Natural Compound Systems.

Saba

Nakano

2003

J. Oleo Sci.

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Laccase, a type of polyphenoloxidase, was found to oxidize unsaturated triacylglycerol under mild reaction conditions in the presence of a simple natural mediator and mediator which is derived from a natural compound. The oxidized products were characterized by UV-and IR-spectroscopic analyses, ferric thiocyanate peroxide analysis and size exclusion chromatography. It was considered that conjugated diene peroxide units were formed in the triacylglycerol without substantial polymerization or degradation reactions of the main chain in the fatty acid residual group. As the mediator, 4-hydroxybenzoic acid, a simple natural phenol, which is secreted by white rot fungi, and the products derived from natural phenols were investigated. 4-Hydroxybenzaldehyde and methyl-4-hydroxybenzoate showed high oxidation activity comparable with synthesized mediators that have been previously reported. Trans-ferulic acid and 2,6-dimethoxyphenol that are not effective for the oxidation of anthracene showed a low oxidation activity for triacylglycerol in the present reaction system. The oxidation activity of the mediators used has some relationship to its oxidation potential. A bell-shaped curve with 4-hydroxybenzaldehyde as its apex may be drawn for the 4-substituted phenols when 4-hydroxybenzoic acid and alkyl-4-hydroxybenzoate were excluded.

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Section: Oxidation Of Triacylglycerol By Laccase-natural Mediatormentioning

confidence: 67%

Section: Results and Discussion 1 Effect Of Mediatormentioning

confidence: 99%

Section: Oxidation Reactionmentioning

confidence: 99%

Section: Measurementsmentioning

confidence: 99%

Section: Measurementsmentioning

confidence: 99%

See 3 more Smart Citations

Oxidation of Triacyiglycerol by Laccase-Natural Mediator and Laccase-Mediator Derived from Natural Compound Systems.

Saba

Nakano

2003

J. Oleo Sci.

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Response Surface Optimization of Enzyme Pretreatment Improves Yield of Ethanol‐Extracted Lipids from Nannochloropsis oceanica

Zhao

Zhang

et al. 2022

Euro J Lipid Sci & Tech

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Nannochloropsis oceanica are marine microalgae that are rich in eicosapentaenoic acid (EPA); in the future, they may become one of the most effective sources of EPA. The cell walls of N. oceanica contain a three‐layered dense structure called algaenan, which hinders the extraction of intracellular lipids. Here, the main variables for the enzyme pretreatment of N. oceanica are optimized using response surface methodology. Under the optimal variables for enzyme pretreatment, the lipid yield and EPA content are increased to 26.9% and 20.7 g/100 g, respectively. Furthermore, lipidomics analysis is carried out utilizing ultra‐high performance liquid‐quadrupole‐time‐of‐flight mass spectrometry to identify the obtained lipids. After enzyme treatment, the betaine lipids (BL) content significantly increases, probably due to laccase and cellulase promoting the release of BL from membrane structure. In comparison, the hydrolysis of neutral lipids, glycolipids, and phospholipids during the enzyme treatment reduces their respective contents. The results of this study suggest that using compound enzymes to pretreat N. oceanica can effectively increase lipids extraction yields by ethanol and improve the EPA contents in lipids. Practical applications: This study indicates that enzyme pretreatment can promote the extraction of lipids, especially lipids with EPA, from N. oceanica or other marine microalgae.

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Banning toxic heavy-metal catalysts from paints: enzymatic cross-linking of alkyd resins

et al. 2013

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Alkyd resins are polyesters containing unsaturated fatty acids that are used as binding agents in paints and coatings. Chemical drying of these polyesters is based on heavy metal catalyzed cross-linking of the unsaturated fatty acid moieties. Among the heavy-metal catalysts, cobalt complexes are the most effective, yet they have been proven to be carcinogenic. Therefore, strategies to replace the cobalt-based catalyst by environmentally friendlier and less toxic alternatives are under development. Here, we demonstrate for the first time that a laccase-mediator system can effectively replace the heavy-metal catalyst and cross-link alkyd resins. Interestingly, the biocatalytic reaction does not only work in aqueous media, but also in a solid film, where enzyme diffusion is limited. Within the catalytic cycle, the mediator oxidizes the alkyd resin and is regenerated by the laccase, which is uniformly distributed within the drying film as evidenced by confocal laser scanning microscopy. During gradual build-up of molecular weight, there is a concomitant decrease of the oxygen content in the film. A new optical sensor to follow oxygen consumption during the cross-linking reaction was developed and validated with state of the art techniques. A remarkable feature is the low sample amount required, which allows faster screening of new catalysts.

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Oxidation of Triacyiglycerol by Laccase-Mediator Systems.

Cited by 3 publications

References 15 publications

Oxidation of Triacyiglycerol by Laccase-Natural Mediator and Laccase-Mediator Derived from Natural Compound Systems.

Oxidation of Triacyiglycerol by Laccase-Natural Mediator and Laccase-Mediator Derived from Natural Compound Systems.

Response Surface Optimization of Enzyme Pretreatment Improves Yield of Ethanol‐Extracted Lipids from Nannochloropsis oceanica

Banning toxic heavy-metal catalysts from paints: enzymatic cross-linking of alkyd resins

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