GC-MS法分析红树林内生真菌Nigrospora sp.的脂肪酸成分

文章采用(硫酸)=2%的甲醇溶液酯化法对红树林内生真菌Nigrospora sp.代谢产物的石油醚部位衍生化,以气相色谱-质谱联用仪分离和鉴定脂肪酸的组成和含量。结果表明:共分离鉴定出24种脂肪酸,占脂肪酸总量的91.32%,其中不饱和脂肪酸占脂肪酸总量的49.97%,饱和脂肪酸占脂肪酸总量的41.35%。     

毛叶山桐子油中脂肪酸组成分析

以毛叶山桐子毛油为原料,利用容量分析方法测定其酸值、碘值及皂化值。以甲酯化方法对山桐子油进行处理后,用GC-MS法对脂肪酸组成和相对含量进行测定,结果显示其碘值为52．15g·（100g）^-1,皂化值195．39mgKOH·g^-1,主要脂肪酸为反式-9,12-十八碳二烯酸、棕榈酸、棕榈油酸等,反式-9,12-十八碳二烯酸含量最高,达59．54％。     

中国南海总状蕨藻中脂肪酸和甾醇GC-MS分析

采用GC—MS分析中国南海总状蕨藻中的脂肪酸及甾醇化合物,鉴定出二十三种脂肪酸及四种甾醇。其中脂肪酸主要为十六碳酸(34．42％)、9,12,15-十八碳三烯酸(10．39％)、9,12-十八碳二烯酸(7．63％)、7,10．13-十六三烯酸(5．60％);甾醇主要为穿贝海绵甾醇。     

大连牡蛎中脂肪酸的提取分析及抗氧化性研究

采用索氏提取法提取大连地区牡蛎脂肪酸,经甲酯化处理后,用气相色谱-质谱联用技术进行分析和鉴定,研究牡蛎中脂肪酸对超氧阴离子自由基的抑制作用。结果表明:牡蛎脂肪酸提取率为21.70%;脂肪酸主要有9-十八碳烯酸、11-二十碳烯酸、十六烷酸、8-十八碳烯酸、5,8,11,14,17-二十碳五烯酸、4,7,10,13,16,19-二十二碳六烯酸等。同时测得牡蛎中脂肪酸对超氧阴离子自由基有很好的抑制作用,所以具有很好的抗氧化性。     

超临界CO2萃取灵香草精油及其化学成分研究

用超临界CO2萃取技术(SFE-CO2),对灵香草(Lysimachia foenum-graecum Hance)进行了萃取,得到灵香草萃取物。探讨了萃取压力、时间及温度等因素对萃取收率的影响,较佳的工艺为:压力25 MPa、温度40℃、时间4 h。超临界CO2法得到的灵香草萃取物收率为4.5%,高于水蒸气法的收率,且香气纯正。采用GC-MS技术对SFE-CO2法得到的灵香草萃取物化学组成进行了分析鉴定,共鉴定出37个化学成分,总质量分数为91.91%,其中主要成分为:苯乙酮、(Z,Z,Z)-9,12,15-十八碳三烯酸甲酯、(Z,Z)-9,12-十八碳二烯酸、9-十六碳烯酸、十七酸、十七酸乙酯、(Z,Z,Z)-9,12,15-十八碳三烯酸乙酯等化合物。     

细雕刻肋海胆性腺脂肪酸的超声波提取与化学成分分析

采用Folch液超声提取细雕刻肋海胆性腺中脂肪酸类脂,经氢氧化钾皂化、甲醇-三氟化硼法甲酯化后,以毛细管气相色谱法、气相色谱-质谱联机技术进行了成分分离分析,配合以线性程序升温等当碳长度值结合标准品对照的方法,对样品中的脂肪酸甲酯定性,用峰面积归一化法定量,并且将脂肪酸甲酯的相对质量分数近似认定为脂肪酸的相对质量分数。鉴定了34种脂肪酸,占峰面积的92.5%。样品中不饱和脂肪酸质量分数超过60%,脂肪酸主要成分(质量分数)为:十六碳酸(13.72%),(Z,Z,Z,Z,Z)-5,8,11,14,17-二十碳五烯酸(12.77%)、(Z,Z,Z,Z,Z,Z)-4,7,10,13,16,19-二十二碳六烯酸(10.63%)、E-6-十八碳烯酸(9.45%)、硬脂酸(7.98%)、Z-11-十八碳烯酸(6.43%)。     

小决明挥发油的提取及其化学成分的GC-MS分析

分别采用超临界CO2萃取法和水蒸气法提取决明子中的挥发性成分,并用气相色谱、气质联用（GC—MS）测定和分析其化学组分。结果显示：超临界CO2萃取法得到的挥发油的主要成分分别是（Z,Z）-9,12-十八碳二烯酸（26．74％）、油酸（24．15％）、n-十六烷酸（13．99％）、大黄根酚（7．26％）、（E）-9-十八碳烯酸（4．52％）和硬脂酸（4．44％）,挥发油中主要含有脂肪酸（75．88％）和蒽醌（7．26％）,得率高于水蒸气法,其决明挥发油在保持较高的亚油酸和油酸含量同时含有更多其它成分,超临界CO2萃取法比水蒸气法更适于提取决明挥发油。     

琼榄果实油提取工艺优化及其脂肪酸成分分析

比较了索氏提取法、超声提取法、加速溶剂萃取法对南药琼榄果实油的提取率。通过正交实验优化了超声提取法的工艺条件,气质联用(GC-MS)法测定了3种方法所提油脂的脂肪酸的成分及相对质量分数。优化后的最佳工艺条件为:每1 g琼榄果实粉溶于9 mL石油醚中(即料液比为1∶9,下同),超声时间10 min,超声功率400W,超声温度70℃。在该条件下,得油率可达31.32%。GC-MS分析表明,3种方法提取的琼榄油中分别含有7、9、8种脂肪酸,其中相对质量分数最高的是13-十八碳烯酸(70.86%、68.71%、69.92%),其次是十六酸(棕榈酸)(17.58%、19.95%、18.73%),再次是十八碳二烯酸(5.12%、6.00%、5.96%)。不饱和脂肪酸占脂肪酸总量达80.61%、78.68%、79.88%。     

鲤鱼肌肉脂肪酸组成的GC/MS分析

目的:研究鲤鱼肌肉中的脂肪含量及其脂肪酸组成。方法:采用国标GB/T 5009.6-2003方法提取鲤鱼肉中的脂肪成分,以碱催化法将其水解并转化为脂肪酸甲酯后,再应用GC/MS联用分析技术,测定分析其脂肪酸组成。结果:新鲜鲤鱼肉中脂肪的含量为6.99 g/100g;共鉴定出34个脂肪酸成分,其中饱和脂肪酸占21.4%,不饱和脂肪酸占78.6%,粗脂肪中的主要脂肪酸成分是油酸、亚油酸和棕榈酸;其余质量分数超过1%的脂肪酸成分有亚麻酸、硬脂酸、10-十八碳单烯酸、9-十六碳单烯酸、棕榈油酸、花生单烯酸和介酸。结论:鲤鱼肌肉中含有丰富的不饱和脂肪酸,分析结果可为相关研究提供基础数据。     

几种荔枝叶挥发性成分的比较研究

采用气相色谱—质谱(GC-MS)联用技术对五个荔枝(LitchichineseSonn)品种的嫩叶的挥发性成分进行了研究,利用MS谱图确认五种嫩叶中的挥发性成分分别为黑叶23种,三月红21种,妃子笑24种,糯米糍25种,桂味22种。它们主要是烃类、酯类、醇类和倍半萜类,共同成分有α-古巴烯、反式石竹烯、大根香叶烯D、3,4-二乙基-1,1’-联二苯、(z,z)-9,12-十八碳二烯酸甲酯、植醇等。     

Determination of Geometrical Isomers of 9,12-Octadecadienoic Acid Present in Food Fats

The present work presents a method to be used in the determination of different geometrical isomers of 9,12-octadecadienoic acid present in food fats. The method is based on isotope dilution, the radioactive isomers needed being prepared by isomerization of cis,cis-9,12-octadecadienoic acid. Radioactivity is acquired through esterification of the isomers by ¹⁴C-diazomethane. For the identification of the isomers infra-red spectrophotometry, alkali isomerization combined with ultraviolet spectrophotometry, gas chromatography, and ozonolysis are used. The isomer to be determined is separated from other fatty acids by argentation thin layer chromatography. The standard deviation of the method was in 15 parallel analyses 0.04%. The sample of food fat to be examined was milk fat, the cis,cis-9,12-octadecadienoic acid content obtained being 0.83%, which corresponded to about one half of octadecadienoic acids of the sample. When a fatty acid mixture with a known composition was analyzed, the cis,cis-9,12-octadecadienoic acid yield was 99.7% on the average, the standard deviation being 0.04%.     

Microbial conversion of palmitoleic acid to 9,12-hexadecadienoic acid (16:2ω4) by Trichoderma sp. AM076

Trichoderma sp. AM076, isolated from a freshwater sample, was found to accumulate 9,12-cis-hexadecadienoic acid (16:2ω4), when grown with palmitoleic acid (16: 1ω7). Methyl myristate was the best carbon source for the conversion of palmitoleic acid to 16:2ω4. The mycelial 16:2ω4 content reached 17.4 mg/g dry mycelia (443 mg/L) when the fungus was grown in a medium that contained 2.0% methyl myristate, 1.5% yeast extract, and 2.0% methyl palmitoleate, pH 6.0, for 5 d at 28°C with shaking. In both nonpolar and polar lipids from the mycelia, 16:2ω4 was detected as one of the major fatty acids when 16:1ω7 was added. It is probable that 16:1ω7 is converted to 16:2ω4 through the Δ12 desaturation reaction.     

Analysis of estolides in technical hydroxylated fatty acids from plant oils

Gel permeation chromatography of hydroxylated fatty acids (HOFA), prepared from various plant oils by a novel technical process, showed the presence of considerable amounts of estolides formed by intermolecular esterification of the HOFA. Thin-layer chromatographic fractionation followed by gas chromatography of the fractions revealed that the nonpolar estolides contain predominantly saturated fatty acids esterified tothero-9, 10-dihydroxy octadecanoic acid or dihydroxy tetrahydrofuran octadecanoic acids, e.g., 9,12-dihydroxy-10, 13-epoxy octadecanoic acid and 10,13-dihydroxy-9, 12-epoxy octadecanoic acid. The fractions of polar estolides consist mainly of intermolecular esters of the above dihydroxy fatty acids.     

假丝酵母99-125脂肪酶促酯化合成生物柴油的研究

1 INTRODUCTION Biodiesel, that is long-chain fatty acid short-chain alcohol esters (methyl, ethyl, propyl and butyl ester), is produced by esterification of fatty acids or inter- esterification of oils and fats. These fatty acid alcohol esters are not only used as important industrial addi- tives and surfactants, but also used for biofuel. The biodiesel is a biodegradable, environmental friendly, renewable substitute of diesel fuel[1]. The traditional production of biodiesel is by chem- i…     

Analysis of hydroxylated fatty acids from plant oils

A novel process has been described recently for the preparation of hydroxylated fatty acids (HOFA) and HOFA methyl esters from plant oils. HOFA methyl esters prepared from conventional and alternative plant oils were characterized by various chromatographic methods (thin-layer chromatography, high-performance liquid chromatography, and gas chromatography) and gas chromatography-mass spectrometry as well as¹H and¹³C nuclear magnetic resonance spectroscopy. HOFA methyl esters obtained fromEuphorbia lathyris seed oil, low-erucic acid rapeseed oil, and sunflower oil contain as major constituents methylthreo-9,10-dihydroxy octadecanoate (derived from oleic acid) and methyl dihydroxy tetrahydrofuran octadecanoates, e.g., methyl 9,12-dihydroxy-10,13-epoxy octadecanoates and methyl 10,13-dihydroxy-9,12-epoxy octadecanoates (derived from linoleic acid). Other constituents detected in the products include methyl esters of saturated fatty acids (not epoxidized/derivatized) and traces of methyl esters of epoxy fatty acids (not hydrolyzed). The products that contain high levels of monomeric HOFA may find wide application in a variety of technical products.     

Synthesis of tetrahydrofuran ring containing oligoethylene glycol ethers from the seed oil of Vernonia anthelmintica

A tetrahydrofuran ring containing oligoethylene glycol ethers has been synthesized from the seed oil of Vernonia anthelmintica. The seed oil was reacted with mono-, di-, and triethylene glycols in the presence of boron trifluoride etherate, followed by saponification and esterification (MeOH/H⁺). The oligoethylene glycol ethers thus obtained were epoxidized with perbenzoic acid. The 9,10-epoxy oligoethylene glycol ethers so formed were intramolecularly cyclized in dry benzene using boron trifluoride etherate as a catalyst to yield the tetrahydrofuran ring containing oligoethylene glycol ethers; methyl 9,12-epoxy, 10-hydroxy-13-[2-hydroxyethyl-1-oxy]; methyl 9,12-epoxy,10-hydroxy-13-[2-hydroxy-3-oxapentyl-1-oxy] and methyl 9,12-epoxy,10-hydroxy-13-[8-hydroxy-3,6-dioxaoctyl-1-oxy]octadecanoates, respectively.     

γ-Linolenic acid inAcer seed oils

The octadecatrienoic acids inAcer negundo L. (maple family) seed oil include both 9,12,15- (1%) and 6.9,12-(7%) isomers. The chief monoenoic acids identified were 9-octadecenoic (21%), 11-eicosenoic (7%), 13-docosenoic (15%), and 15-tetracosenoic (7%). Also present is a considerable amount of 9,12-octadecadienoic acid. Investigation of ten other Aceraceae revealed their seed oils to have a similar fatty acid composition.     

Positional distribution of octadecadienoic acids in sponge phosphatidylethanolamines

The distribution of C14–C22 fatty acids in the phosphatidylethanolamines isolated from the spongesAgelas sp. andSpongia tampa was investigated. Selective changes with phospholipase A₂ (fromAgkistrodon halys blomhoffii) followed by thin-layer chromatographic separation of the resulting lysophosphatidylethanolamines and free fatty acids and subsequent methylation with HCl/MeOH and diazomethane, respectively, revealed that the 5,9-octadecadienoic acid and the 9,12-octadecadienoic acid present showed no preference for either positionsn-1 orsn-2 in these phosphatidylethanolamines. The other saturated and unsaturated fatty acids with chains between 14 and 22 carbons long were also found to be equally distributed between positionssn-1 andsn-2 in the phosphatidylethanolamines in these sponges. The results contrast with what is known about the distribution in most mammalian phospholipids, such as the phosphatidylcholines from human erythrocytes, where octadecadienoic acid typically occupies thesn-2 position.     

Microbial Conversion of Vegetable Oil to Rare Unsaturated Fatty Acids and Fatty Alcohols by an <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> Isolate

We isolated two new microorganisms capable of converting vegetable oil to several rare unsaturated fatty acids and rare unsaturated fatty alcohols from a soil sample. The strains were identified as belonging to the same genus and species, Aeromonas hydrophila. The rare unsaturated fatty acids and rare unsaturated fatty alcohols were accumulated as a wax ester form by the strains. Compared to other strains, the A. hydrophila isolates effectively decreased fatty acid chain lengths and converted rapeseed oil, which is rich in 9-C18:1 fatty acid, into rare fatty acids, such as 7-C16:1 fatty acid and 5-C14:1 fatty acid. Furthermore, the A. hydrophila isolates converted the resulting fatty acids to rare unsaturated fatty alcohols, such as 7-C16:1 fatty alcohol and 5-C14:1 fatty alcohol. The isolates also converted safflower oil, which is rich in 9,12-C18:2 fatty acid, to 7,10-C16:2 fatty acid, 5,8-C14:2 fatty acid, 9,12-C18:2 fatty alcohol, 7,10-C16:2 fatty alcohol, and 5,8-C14:2 fatty alcohol. 7,10,13-C16:3 fatty acid, 9,12,15-C18:3 fatty alcohol, and 7,10,13-C16:3 fatty alcohol were also converted from linseed oil, which is rich in 9,12,15-C18:3 fatty acid, by the A. hydrophila isolates. These fatty acids and fatty alcohols are rarely found in natural oils. Since decreasing fatty acid carbon chain lengths from the carboxyl end and reducing unsaturated fatty acids to unsaturated fatty alcohols are both difficult reactions to accomplish by chemical means, we suggest that these A. hydrophila isolates may facilitate introduction of new bioprocess for producing rare unsaturated fatty acids and rare unsaturated fatty alcohols, especially fatty alcohols harboring more than two double bonds.