共轭亚油酸锌的合成工艺研究

通过利用共轭亚油酸的弱酸性质,将共轭亚油酸制成盐,以期生理功能的改变,本文利用具有生物功能活性的共轭亚油酸,先与氢氧化钠反应得到共轭亚油酸的钠盐溶液,再加入氯化锌溶液得到共轭亚油酸锌盐,平均收率为67%。为共轭亚油酸锌制成制剂的进一步研究提供了原料。     

共轭亚油酸及其酯类衍生物的氧化稳定性

采用分析氧化过程中脂肪酸组成的方法对共轭亚油酸及其衍生物的氧化稳定性进行了研究,结果表明,与亚油酸相比共轭亚油酸初级氧化产物形成的速度大,而共轭亚油酸次级氧化产物的形成速度要慢些;共轭亚油酸乙酯与亚油酸乙酯的氧化稳定性差别不大,比共轭亚油酸的氧化稳定性差,共轭亚油酸蔗糖酯的氧化稳定性最差。     

共轭亚油酸乙酯的合成

采用间歇式反应 ,以硫酸、磷酸、对甲苯磺酸为催化剂对共轭亚油酸乙酯进行了合成 ,并采用正交实验设计研究了物料比、反应温度、反应时间、催化剂用量对产品收率和品质的影响。硫酸、对甲苯磺酸催化活性佳 ,磷酸催化活性差。得到了如下合成工艺条件 :硫酸催化 ;n(共轭亚油酸 )∶n(无水乙醇 ) =1∶6;酯化反应温度 76℃ ;反应时间 1h ;催化剂用量为共轭亚油酸质量的 2 5 % ,收率可达 75 % ,产品w(共轭亚油酸乙酯 ) =77%～ 82 %。     

嗜酸乳酸杆菌转化亚油酸为共轭亚油酸工艺条件的研究

对嗜酸乳酸杆菌转化亚油酸为共轭亚油酸的工艺条件进行了优化,其优化的工艺条件为:亚油酸与发酵液的比例为0.1%(体积比)、反应温度36℃、培养时间36 h、pH值6.0,此时共轭亚油酸的产率达37.85%.同时对共轭亚油酸异构体的组成进行了气相色谱分析.     

碱法异构化亚油酸甲酯制备共轭亚油酸

该文探索在乙二醇溶剂中以氢氧化钠碱法异构化亚油酸甲酯制备共轭亚油酸的方法,适宜的异构化条件为m(氢氧化钠)∶m(亚油酸甲酯)∶m(乙二醇)=1∶5∶8.4,170℃反应4 h,亚油酸甲酯转化率和共轭亚油酸产率分别为92.4%和89.3%。该法比目前常用的亚油酸原料法的优越之处体现在:以氢氧化钠取代常用碱氢氧化钾,降低成本;以亚油酸甲酯取代亚油酸为原料,避免了原料本身大量消耗碱;反应初期避免原料大量皂化,减小了体系的传质阻力,因而减少了溶剂乙二醇消耗量。     

红花油制取共轭亚油酸的研究

以新疆克拉玛依厂的红花油为原料,以丙三醇为溶剂,在KOH的碱性催化作用下,将红花油先转化成亚油酸钾;再利用异构化反应制得浅黄色的共轭亚油酸产品。对产品进行了薄层层析法和紫外分光光度法定性分析,并定量分析了红花油异构化反应的程度。本研究对红花油的深加工将起到很好的推动作用。     

共轭亚油酸粉末化微胶囊的制备

研究了喷雾干燥法制备共轭亚油酸微胶囊的工艺参数及配比条件。结果表明,最佳的工艺参数及配比条件为:乳液80℃热处理60 m in,乳化剂蔗糖酯加入量为水液的1%~1.5%,大豆分离蛋白与麦芽糊精质量比为1∶4,壁材中玉米糖浆含量38.5%,固形物含量16.7%,共轭亚油酸理论含量16%左右,进风温度130~150℃,进料流量(2.5~3.5)×150 mL/h,进料温度35℃,进风流量1.1 m3/m in左右,喷嘴压力180 kPa。制备出的共轭亚油酸微胶囊有较好的产品质量。     

乙二醇单丁醚为溶剂制备共轭亚油酸的研究

以乙二醇单丁醚作为溶剂,KOH作催化剂,碱催化异构化法用豆油制备共轭亚油酸。通过正交设计,紫外光谱分析考察了4种因素对亚油酸转化率的影响,并得出制备高亚油酸油脂合适的工艺条件:反应温度135℃,反应时间3 h,强碱催化剂与原料质量比为0.4∶1,原料与溶剂质量比为2∶3。在此条件下,亚油酸的平均转化率达到96.8%。结果表明,该溶剂能使反应在均相体系中较为温和的温度条件下较短的时间内完成。     

乙二醇单丁醚为溶剂制备共轭亚油酸的研究

以乙二醇单丁醚作为溶剂,KOH作催化剂,碱催化异构化法用豆油制备共轭亚油酸.通过正交设计,紫外光谱分析法考察了4种因素对亚油酸转化率的影响,并得出制备高亚油酸油脂合适的工艺条件:反应温度135℃,反应时间3 h,强碱催化剂与原料质量比为0.4:1,原料与溶剂质量比为2:3.在此条件下,亚油酸的平均转化率超过96%.结果表明,该溶剂能使反应在均相反应体系中较为温和的温度条件下较短的时间内完成.     

共轭亚油酸产业化项目通过鉴定

日前 ,由山东省青岛澳海生物公司承担的共轭亚油酸产业化项目通过专家鉴定。共轭亚油酸是近 2 0年来人类发现的最重要的功能性脂肪酸 (简称CLA)。上世纪 90年代 ,欧美等发达国家的众多专家学者通过对共轭亚油酸产品的研究和开发 ,使该产品很快在健康功能性食品及医药领域得到推广应用。2 0 0 1年初 ,山东省青岛澳柯玛集团与国家海洋局第一研究所合作 ,共同实施共轭亚油酸研究成果的转化 ,不久便推出了共轭亚油酸系列产品 ,并开始出口 ,出口量曾一度占到全国同类出口产品的 95 %。 2 0 0 3年 1 1月承担该项目的国家海洋科学研究中心产业化…     

Biocatalysis of linoleic acid to conjugated linoleic acid

CLA refers to a group of geometrical and positional isomers of linoleic acid (LA) with conjugated double bonds. CLA has been reported to have diverse health benefits and biological properties. Traditional organic synthesis is highly capital-intensive and results in an isomeric mixture of CLA isomers. Biotechnology presents new alternatives to traditional lipid manufacturing methods. The objective of this study was to examine the effect of protein isolation procedures on linoleate isomerase (LAI) recovery from microbial cells and biocatalysis of LA to CLA. Protein isolation experiments were carried out using Lactobacillus acidophilus L1 and two strains of Lactobacillus reuteri (ATCC 23272 and ATCC 55739). Under the same assay conditions, ATCC 55739 had the highest LAI activity among the microbial cultures examined in this study. Efficiency of cell lysis methods, which included various combinations of lysozyme and mutanolysin treatments in combination with sonication and osmotic rupture of cells with liquid nitrogen, was very low. Although treatment of cell material with a detergent (octylthioglucoyranoside) freed a significant amount of LAI activity into the solution, it was not sufficient to recover all the LAI activity from the residual cells. Crude LAI preparations produced mainly the cis-9,trans-11 CLA isomer. Time and substrate/protein ratio had a significant effect on biocatalysis of LA to CLA. It appears that the mechanism and kinetics of enzymatic conversion of LA to CLA are quite complex and requires further research using pure LAI preparations. Published with approval of the Director, Oklahoma Agricultural Experiment Station.     

共轭亚油酸微胶囊化中壁材优化的研究

以大豆分离蛋白(SPI)、麦芽糊精(MD)为主要壁材,研究了以喷雾干燥法对共轭亚油酸(CLA)微胶囊化时其复合壁材的优化及其方法。利用界面膜成膜理论分析了各组分配比对微胶囊化效果的影响,进而指导最优条件的选择。结果表明,SPI与MD质量比为1∶4,壁材中玉米糖浆质量分数为38.5%,固形物质量分数在16.7%,CLA添加量以微胶囊质量分数计约为16%时,微胶囊化产率(MEY)和效率(MEE)分别达到了98%和85%;加入明胶可进一步提高微胶囊产品的含油量而微胶囊化效果基本不变。     

Effects of conjugated linolenic acid and conjugated linoleic acid on lipid metabolism in mice

The effects of two isomers of conjugated linolenic acid (CLnA), α‐eleostearic acid (α‐ESA) and punicic acid (PA), on body fat and lipid metabolism were investigated, compared with a conjugated linoleic acid (CLA) mixture (primarily cis9,trans11‐ and trans10,cis12‐18:2) and α‐linolenic acid (ALA), a non‐conjugated octadecatrienoic acid, in the present study. ICR mice were fed either a control diet or one of four experimental diets supplemented with 1% α‐ESA, 1% PA, 1% CLA mixture and 1% ALA in the form of triacylglycerols (TAG) for 6 weeks. The weights of perirenal and epididymal adipose tissues were significantly decreased while the liver weight was significantly increased in mice fed CLA, compared with the control. In contrast to CLA, the tissue weights in α—ESA‐, PA‐ and ALA‐fed mice were not affected. No significant differences were observed in TAG, total cholesterol, high‐density lipoprotein and low‐density lipoprotein cholesterol levels among the five groups. The liver TAG level was significantly decreased in mice fed α‐ESA and PA while it was significantly increased in mice fed the CLA mixture. These results indicate that CLnA and CLA have differential effects on body fat mass and liver TAG levels in mice.     

Biosynthesis of conjugated linoleic acid in humans

This paper deals with the reanalysis of serum lipids from previous studies in which deuterated fatty acids were administered to a single person. Samples were reanalyzed to determine if the deuterated fatty acids were converted to deuterium-labeled conjugated linoleic acid (CLA, 9c, 11t-18∶2) or other CLA isomers. We found 11-trans-octadecenoate (fed as the triglyceride) was converted (Δ9 desaturase) to CLA, at a CLA enrichment ofca. 30%. The 11-cis-octadecenoate isomer was also converted to 9c, 11c-18∶2, but at <10% the concentration of the 11t-18∶1 isomer. No evidence (within our limits of detection) for conversion of 10-cis-or 10-trans-octadecenoate to the 10,12-CLA isomers (Δ12 desaturase) was found. No evidence for the conversion of 9-cis, 12-cis-octadecadienoate to CLA (via isomerase enzyme) was found. Although these data come from isomerase enzyme) was found. Although these data come from four single human subject studies, data from some 30 similar human studies have convinced us that the existence of a metabolic pathway in one subject may be extrapolated to the normal adult population.     

Epoxidation of a conjugated linoleic acid isomer

Epoxidation of methyl (9Z, 11E)‐octadecadienoate ( 1 ) with various epoxidizing agents viz. m‐chloroperoxybenzoic acid, dimethyl dioxirane, methyltrioxorhenium/hydrogen peroxide, potassium peroxomonosulfate (Oxone, 2KHSO₅ · KHSO₄ · K₂SO₄)/tetrahydrothiopyran‐4‐one, and Novozyme 435/hydrogen peroxide is described. The reactions furnished the corresponding mono‐epoxy [methyl (11, 12E)‐epoxy‐(9Z)‐octadecenoate ( 2 ) and methyl (9, 10Z)‐epoxy‐(11E)‐octadecenoate ( 3 )] and a mixture of diastereomers of syn‐ and anti‐diepoxy‐stearate [methyl (9, 10Z;11, 12E)‐diepoxystearate ( 4a‐4d )], which were identified by a combination of spectroscopic and spectrometric analyses.     

Lipase-catalyzed fractionation of conjugated linoleic acid isomers

The abilities of lipases produced by the fungus Geotrichum candidum to selectively fractionate mixtures of conjugated linoleic acid (CLA) isomers during esterification of mixed CLA free fatty acids and during hydrolysis of mixed CLA methyl esters were examined. The enzymes were highly selective for cis-9,trans-11–18∶2. A commercial CLA methyl ester preparation, containing at least 12 species representing four positional CLA isomers, was incubated in aqueous solution with either a commercial G. candidum lipase preparation (Amano GC-4) or lipase produced from a cloned high-selectivity G. candidum lipase B gene. In both instances selective hydrolysis of the cis-9,trans-11–18∶2 methyl ester occurred, with negligible hydrolysis of other CLA isomers. The content of cis-9,trans-11–18∶2 in the resulting free fatty acid fraction was between 94 (lipase B reaction) and 77% (GC-4 reaction). The commercial CLA mixture contained only trace amounts of trans-9,cis-11–18∶2, and there was no evidence that this isomer was hydrolyzed by the enzyme. Analogous results were obtained with these enzymes in the esterification in organic solvent of a commercial preparation of CLA free fatty acids containing at least 12 CLA isomers. In this case, G. candidum lipase B generated a methyl ester fraction that contained >98% cis-9,trans-11–18∶2. Geotrichum candidum lipases B and GC-4 also demonstrated high selectivity in the esterification of CLA with ethanol, generating ethyl ester fractions containing 96 and 80%, respectively, of the cis-9,trans-11 isomer. In a second set of experiments, CLA synthesized from pure linoleic acid, composed essentially of two isomers, cis-9,trans-11 and trans-10,cis-12, was utilized. This was subjected to esterification with octanol in an aqueous reaction system using Amano GC-4 lipase as catalyst. The resulting ester fraction contained up to 97% of the cis-9,trans-11 isomer. After adjustment of the reaction conditions, a concentration of 85% trans-10,cis-12–18∶2 could be obtained in the unreacted free fatty acid fraction. These lipase-catalyzed reactions provide a means for the preparative-scale production of high-purity cis-9,trans-11–18∶2, and a corresponding CLA fraction depleted of this isomer.     

Inhibitory effect of conjugated linoleic acid on linoleic acid elongation in transformed yeast with human elongase

Conjugated linoleic acid (CLA; 18∶2) refers to a group of positional and geometric isomers derived from linoleic acid (LA; Δ9, 12–18∶2). Using a growing baker's yeast (Saccharomyces cerevisiae) transformed with human elongase gene, we examined the inhibitory effect of CLA at various concentrations (10, 25, 50, and 100 μM) on elongation of LA (25 μM) to eicosadienoic acid (EDA; Δ11,14–20∶2). Among four available individual CLA isomers, only c9,t11- and t10,c12-isomers inhibited elongation of LA to EDA. The extent of inhibition (ranging from 20 to 60%) was related to the concentration of CLA added to the medium. In the meantime, only these two isomers, when added at 50 μM to the media, were elongated to conjugated EDA (c11,t13- and t12,c14–20∶2) by the same recombinant elongase at the rate of 28 and 24%, respectively. The inhibitory effect of CLA on LA elongation is possibly due to competition between CLA isomers and LA for the recombinant elongase. Thus, results from this study and a previous study suggest that the biological effect of CLA is exerted through its inhibitory effect on Δ6-desaturation as well as elongation of LA which results in a decrease in long-chain n−6 fatty acids and consequently the eicosanoid synthesis.     

烷基磷酸酯与共轭亚油酸形成杂化囊泡的研究

脂肪酸囊泡(FAV)的中空壳核结构能够包埋活性分子。为改善FAV仅在其p Ka附近形成的缺陷,以拓宽FAV的应用范围,将安全性和温和性阴离子表面活性剂烷基磷酸酯钾盐(MAPK)添加到共轭亚油酸中,通过动态激光光散射(DLS)和透射电子显微镜(TEM)研究了囊泡化的pH窗口,发现9%MAPK存在时就可以在中性至酸性环境中形成杂化FAV,不明显改变原有FAV的形貌及粒径,且随着MAPK添加量的增大,杂化FAV的pH窗口有逐渐拓宽的趋势。这一结果显示了杂化FAV在化妆品和个人卫生护理用品等领域的应用前景。