Synthesis and surface properties of monoeicosapentaenoyl trehalose
ABSTRACT Eicosapentaenoyl trehalose was transesterified with eicosapentaenoic acid ethyl ester and trehalose in tert-butanol using microbial lipase. Reversed phase high-performance liquid chromatography coupled with diode array detection
and electrospray ionization mass spectrometry (RPHPLC-DAD–ESI-MS) analysis showed that the monoester and diester existed in
the reaction mixture. Silica gel column chromatography was adopted to pretreat the reactive mixture then the eluted monoeicosapentaenoyl
trehalose was further purified using semi-preparative HPLC. The structure of the compound was confirmed by ESI-MS and nuclear
magnetic resonance (NMR) as 6-O-monoeicosapentaenoyl trehalose. Subsequently, the surface properties of monoeicosapentaenoyl trehalose were investigated.
The results indicated that the surface tension, CMC, γCMC and ΔG
mico decreased with increasing temperature, however, the area occupied per molecule increased very little.
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ABSTRACT: This paper reports on the synthesis of triglycerides by enzymatic esterification of polyunsaturated fatty acids (PUFA) with glycerol. A PUFA concentrate obtained from cod liver oil was used to optimize the reaction to favor triglyceride synthesis with lipases. The type and amount of lipase and organic solvent, glycerol content, temperature, water content, and amount and time of addition of molecular sieves were studied. The optimal reaction mixture and conditions were: 9 mL hexane, 60°C, 0.5% (vol/vol) water, 1 g molecular sieves added after 24 h of reaction, glycerol/fatty acid molar ratio 1:3 and 100 mg of Novozym 435 (Novo Nordisk A/S) lipase. Under these conditions, an enriched triglyceride yiedl of 84.7% containing 27.4% eicosapentaenoic acid and 45.1% docosahexaenoic acid was obtained from a cod liver oil PUFA concentrate.Journal of Oil & Fat Industries 01/1998; 75(10):1329-1337. · 1.59 Impact Factor
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ABSTRACT: Synthesized PCs containing docosahexaenoic acid (DHA), arachidonic acid (AA), linoleic acid (LA), and palmitic acid (PA) at known positions in the glycerol moiety were oxidized in liposomes, bulk, and organic solvent. In bulk and organic solvent, the oxidative stability of PC decreased with increasing degrees of unsaturation. However, the degree of unsaturation had little effect on the stability of PC in liposomes. The oxidative stability of PC in liposomes would be affected by the chemical reactivity based on the degree of unsaturation and by the conformation of fatty acyl component in PC bilayers. When the oxidative stability of 1-PA-2-LA-PC or 1-PA-2-AA-PC was compared with that of a 1:1 (mol ratio) mixture of 1,2-diPA-PC + 1,2-diLA-PC, or 1,2-diPA-PC + 1,2-diAA-PC, respectively, the former PC was more oxidatively stable than that of the latter PC mixture in all oxidation systems, although the degree of unsaturation of 1-PA-2-PUFA-PC was the same as that of the corresponding mixture of diPA-PC + diPUFA-PC. The higher oxidative stability of 1-PA-2-PUFA-PC than that of a corresponding mixture of diPA-PC + diPUFA-PC in liposomes was suggested to be due to the different conformation of PC bilayers and the different rate of hydrogen abstraction by free radicals from intermolecular and intramolecular acyl groups.Bioscience Biotechnology and Biochemistry 01/2003; 66(12):2573-7. · 1.27 Impact Factor
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ABSTRACT: The use of polyunsaturated fatty acids (PUFA) as medicine or in functional diets requires high purity. An industrial purification method for PUFA from Schizochytrium sp. SR21 oil was investigated. This oil contains fewer unwanted components than fish oils. Docosahexaenoic acid and docosapentaenoic acid ethyl esters (DHA-E and DPA-E) were prepared by treatment of this oil with ethanol and 1 N potassium hydroxide in hexane. DHA-E and DPA-E were purified by an industrial high-performance liquid chromatography (HPLC) plant. The separation plant consists of two columns (400 mm i.d., 1,000 mml) with temperature-controlled water jackets and double-plunger (four heads) injection and eluent pumps. This plant was computer-controlled and equipped with an explosion-prevention system. The packed material was octadecylsilica (reverse-phase ODS), and the eluent was methyl alcohol/water (98:2). DHA-E and DPA-E from single-cell oil were highly purified by this industrial HPLC method in a one-step process. The DHA-E and DPA-E obtained were better than 99% purity.Journal of Oil & Fat Industries 01/1997; 74(11):1435-1440. · 1.59 Impact Factor