Use of RP-TLC to Investigate the Solubility in Water of Fatty Acids,Hydroxy Fatty Acids and their Esters

JPC – Journal of Planar Chromatography – Modern TLC - Long-chain fatty acids and hydroxy fatty acids and their esters have been separated by reversed-phase thin-layer chromatography...     

Visualizing Agents for Esters of Higher Fatty Acids in TLC

JPC – Journal of Planar Chromatography – Modern TLC - Eighteen new agents have been used for visualizing eight esters of higher fatty acids after chromatography on silica gel, on a...     

Investigation of the Correlation between RM Values and Selected Topological Indexes for Higher Alcohols,Higher Fatty Acids and their Methyl Esters in RPTLC

JPC – Journal of Planar Chromatography – Modern TLC - Homologous series of higher fatty acids, higher alcohols, and methyl esters of higher fatty acids have been separated by RPTLC. The...     

Monohydroxy‐Substituted Polyunsaturated Fatty Acids from Swertia japonica

Fourteen monohydroxy‐substituted polyunsaturated fatty acids, including two new compounds, (9Z,12S,13E,15Z)‐12‐hydroxyoctadeca‐9,13,15‐trienoic acid ( 10 ) and (9Z,12Z,14E,16R)‐16‐hydroxyoctadeca‐9,12,14‐trienoic acid ( 13 ), and 12 known ones, i.e., 1 – 9, 11, 12 , and 14 , were isolated from the whole plants of Swertia japonica Makino , and characterized as the corresponding methyl esters 1a – 14a . Their structures were elucidated by analysis of the corresponding spectroscopic data, and the absolute configurations of 10a and 13a were determined by the Mosher‐ester method. The CD spectra (Table) of compounds 1a – 14a are briefly discussed. This is the first report on the isolation of monohydroxy‐substituted polyunsaturated fatty acids from the Swertia genus in Gentianaceae.     

Chemistry and Biochemistry of Unsaturated Fatty Acids

Although unsaturated fatty acids have long been known to accompany saturated fatty acids in most lipids, qualitative and quantitative determination of fatty acid patterns only became possible with the advent of modern analytical methods. Present day knowledge of the chemical structure, physical properties, and metabolism of unsaturated fatty acids provides the basis for the development of new concepts of their function. Thus unsaturated fatty acids crucially determine the properties of biological membranes. Moreover, essential fatty acids are precursors of prostaglandins.     

大鼠肝过氧化物酶体中脂肪酸的分析

 用双 (2 乙基己基 )酚酞酸酯 (DEHP)诱导大鼠肝过氧化物酶体增殖 ,再用蔗糖密度梯度离心法分离大鼠肝细胞过氧化物酶体 ,并用十七烷酸作内标 ,以毛细管气相色谱法在非极性SPB 1石英毛细管柱上对其中的 11种脂肪酸进行分离测定。正常组和诱导组的大鼠肝过氧化物酶体中的不饱和脂肪酸和长链脂肪酸所占总脂肪酸的比例及总脂肪酸的统计结果是 :诱导组的不饱和脂肪酸的含量高于正常组的 (P <0 0 5 ) ,而两个组的脂肪酸总量及长链脂肪酸的含量无明显差别。结果提示 :诱导组的大鼠肝过氧化物酶体的脂肪酸成分发生了变化 ,其膜结构与正常组的不相同。     

Planar Chromatography of Free Industrial Amino Acids

JPC – Journal of Planar Chromatography – Modern TLC - Amino acids such as L-serine, L-threonine, L-phenylalanine, L-tryptophan, L-lysine, L-ornithine, L-arginine, L-valine, and...     

Thin-Layer Chromatography of Phenolic Acids on Aminopropylsilica

JPC – Journal of Planar Chromatography – Modern TLC - The possibility of using aminopropylsilica TLC plates for determination of phenolic acids has been investigated. Eighteen phenolic...     

New Steryl Esters of Fatty Acids from the Mangrove Fungus Aspergillus awamori

The polyhydroxylated ergostane‐type sterol 9 , its derivatives 10 – 15 , and the fatty acid esters 1 – 8 were isolated from a fungus strain which was collected from mangrove areas at Wenchang, Hainan Province, P. R. China, exhibited potent cytotoxic activity, and was identified as Aspergillus awamori. The structures of 1 – 15 were elucidated by spectroscopic and chemical methods. Among them, the six steryl esters 1 – 6 of fatty acids were new compounds, i.e., (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐palmitate ( 1 ), (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐stearate ( 2 ), (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐oleate ( 3 ), (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐linoleate ( 4 ), (3β,5α,6β,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐palmitate ( 5 ), and (3β,5α,6β,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐stearate ( 6 ). The related known fatty acids stearic acid (=octadecanoic acid) and palmitic acid (=octadecanoic acid) were also obtained. A speculative biogenetic relationship of the metabolites is proposed. The known polyhydroxylated sterols and derivatives showed cytotoxic activities, in agreement with earlier reports. The cytotoxic activities against B16 and SMMC‐7721 cell lines of the new steryl esters 1 – 6 by the MTT method were weak.     

烘丝前后烟丝多元酸和高级脂肪酸变化研究

烟草中的多元酸对抽吸品质有重要影响,它们能与生物碱结合成盐,调节烟草中碱性成分的挥发性。高级脂肪酸可分成饱和与不饱和两类,饱和脂肪酸能增加烟气的脂肪味、腊味并使之圆和;不饱和脂肪酸增加烟气的丰满度和粗糙感。卷烟在烘丝过程中由于温度、湿度的变化而引起烟草内部化学成分的变化。本文应用甲酯衍生化和GC-MS法,对卷烟加工过程中烘丝工序前后的多元酸和高级脂肪酸进行了定性定量分析。为卷烟配方和加工工艺参数的优化提供理论依据。     

A Novel Synthesis of 4‐Pyridazineacetic Acids via Ring Expansion of N‐Cyanomethylated 3‐Pyrazoline‐4‐acetic Acids

A novel synthetic route to 4‐pyridazineacetic acids 10 – 12 has been achieved by the ring‐expansion reaction of N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7 – 9 . 1H‐Pyrazole‐4‐acetic acids 1 – 3 were reacted with iodoacetonitrile in the presence of triethylamine in refluxing acetonitrile to give the corresponding C‐cyanomethylated 1H‐pyrazole‐4‐acetic acids 4 – 6 as major products together with N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7 and 8 as minor products. On the other hand, reactions of 1 and 3 with chloroacetonitrile in the presence of triethylamine in refluxing chloroform afforded the corresponding N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7 and 9 as major products. Thermal treatment of 7 – 9 with sodium hydride in N,N‐dimethylformamide caused ring expansion to yield the corresponding 4‐pyridazineacetic acids 10 – 12 .     

油菜蜂花粉中脂肪酸的GC-MS分析

以石油醚和乙醚为溶剂，采用索氏抽提法提取油菜蜂花粉中的粗脂肪，进行甲酯化处理，并用GC－MS技术对脂肪酸甲酯进行分离鉴定，共鉴定出10种脂肪酸；测定其相对含量，其中不饱和脂肪酸相对含量高达76.0%，多不饱和脂肪酸相对含量为53.2%。     

芥末种子中脂肪酸的 GC－MS分析

报道了用色谱－质谱分析芥末种中脂肪酸成分及其含量,结果表明芥末种子中含有丰富的饱和的和不饱和的脂肪酸及其乙酯,为芥末种子的开发利用提供了信息。     

Optimization of the TLC Separation of Seven Amino Acids

JPC – Journal of Planar Chromatography – Modern TLC - A ternary mobile phase for thin-layer chromatographic separation and identification of seven amino acids on microcrystalline...     

柽柳实中挥发油和脂肪酸分析

首次研究了维药细穗柽柳(Tamarix leptostachys Bunge)实中挥发油和脂肪酸的化学成分。 分别采用药典中的挥发油提取法和索式取提法提取柽柳实中的挥发油和脂肪酸,使用气质联用技术获取总离子流图,各色谱峰相应的质谱图经过NIST2011标准谱库检索定性,并采用峰面积归一化法进行定量分析,计算各成分的相对百分含量。 两种方法分别鉴定出48种挥发油和19种脂肪酸。 挥发油主要成分为芳香类化合物(43.71%)、芳香性醛酮类(20.58%)、脂肪酸类(13.03%)、酯类(17.36%)和醇类(4.19%)等。 脂肪酸主要成分为棕榈酸(35.61%)、亚油酸(27.26%)和油酸(11.33%)等,其中不饱和脂肪酸含量占总脂肪酸含量的38.65%。 维药细穗柽柳实中富含丰富的挥发油和不饱和脂肪酸,具有很好的开发利用价值。     

Normal and Reversed-Phase TLC Determination of Rosmarinic and Valerenic Acids

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic properties of valerenic and rosmarinic acids have been studied by normal- and reversed-phase TLC with eight...     

TLC Separation of Amino Acids with a Green Mobile Phase

JPC – Journal of Planar Chromatography – Modern TLC - Thin-layer chromatography (TLC) of fifteen amino acids was performed using silica gel and alumina impregnated with micellar...     

Inhibitory Effects of Fatty Acids on the Activity of Mushroom Tyrosinase

The effects of fatty acids, octanoic acid, (2E, 4E)-hexa-2,4-dienoic acid, hexanoic acid, (2E)-but-2-enoic acid, and butyric acid on the activities of mushroom tyrosinase have been investigated. The results showed that the fatty acids can potently inhibit both monophenolase activity and diphenolase activity of tyrosinase, and that the unsaturated fatty acids exhibited stronger inhibitory effect against tyrosinase than the corresponding saturated fatty acids, and the inhibitory effects were enhanced with the extendability of the fatty acid chain. For the monophenolase activity, the fatty acids could not only lengthen the lag period, but also decrease the steady-state activities. For the diphenolase activity, fatty acids displayed reversible inhibition. Kinetic analyses showed that octanoic acid and hexanoic acid were mixed-type inhibitors and (2E,4E)-hexa-2,4-dienoic acid and (2E)-but-2-enoic acid were noncompetitive inhibitors. The inhibition constants have been determined and compared.     

气相色谱法测定线虫中的脂肪酸含量

ematode is a small organism and the traditional purification method needs a lot of nematodes , but it is difficult for us to foster many nematodes.The fatty acids in nematode were esterified directly in our analytical method,so that,the error is reduced the and sensitivity is improved. The results showed that thisimproved analysis method could be used for rapid and satisfactory determination of the fatty acid change during storagr of this group of nematodes.     

Light‐Driven Enzymatic Decarboxylation of Fatty Acids

The photoenzymatic decarboxylation of fatty acids to alkanes is proposed as an alternative approach for the synthesis of biodiesel. By using a recently discovered photodecarboxylase from Chlorella variabilis NC64A (CvFAP) we demonstrate the irreversible preparation of alkanes from fatty acids and triglycerides. Several fatty acids and their triglycerides are converted by CvFAP in near‐quantitative yield and exclusive selectivity upon illumination with blue light. Very promising turnover numbers of up to 8000 were achieved in this proof‐of‐concept study.