Thin-layer Chromatography of Cyclodextrins

N-methyl-2-pyrrolidone (NMP) is known for its multi-solvent properties. However, its biological, especially immunological significance still remains to be elucidated. In this study, we show for the first time that NMP stimulates the skin immune system by activating epidermal Langerhans cells (LCs). In contrast with the placebo tape, when the NMP-containing adhesive tape was applied on murine skin, LCs were stimulated immediately. Activated LCs not only exhibited enhanced expression of major histocompatibility complex class II and morphological changes, including the loss of dendrites, but also migrated effectively to draining lymph nodes. In addition, application of the tyrosine-related protein-2 peptide, which is the cytotoxic T lymphocyte (CTL) epitope against B16 melanoma, in combination with the NMP tape, resulted in explosive expansion of specific CTLs in mouse spleens. Taken together, these results demonstrate a novel role of NMP as an adjuvant in percutaneous peptide immunization.     

Circular Thin-layer Chromatography of Oligosaccharides

The physicochemical properties and chemical constituents of the blue protein from rice bran were investigated. The blue protein was a copper-containing glycoprotein, the molecular weight of which was found to be 18,300 Daltons by the sedimentation equilibrium method assuming the partial specific volume 0.72 cm³ g^?1. The hexose and pentose contents were 5.49 and 4.01 g per 100 g protein respectively. The copper content was 0.38% which corresponded to 1.09 atoms per one molecule of the protein. The electron spin resonance spectrum showed that the copper was in a cupric state. The standard oxidation-reduction potential of the copper was found to be +275 mV at 20°C and at pH 7.39. The visible and near infrared absorption maxima were found at 450, 600 and 890 mμ, and the 450 mμ band was optically active in the optical rotatory dispersion exhibiting a large Cotton effect.     

Thin-layer Chromatography of Some Substituted Naphthoquinones

The satisfactory method for the separation of 1,4-naphthoquinone derivatives by thin-layer chromatography, using silica gel plate and various solvents as developer, is described.

It was found that the R_F values were markedly influenced by the presence or absence of hydroxyl and amino groups.     

Simple Method for Analyzing Phosphoamino Acids by Thin-layer Chromatography: Application to Elongation Factor 1 from Wheat Embryo

A simple and rapid method was developed separating phosphoserine, phosphothreonine, phosphotyrosine, phosphoric acid, and ATP by one-dimensional cellulose thin-layer chromatography, using a freshly prepared solvent system of 1-butanol–formic acid–water (5:2:1). This system was applied to determine phosphoamino acid (phosphoserine) of wheat elongation factor 1β phosphorylated by casein kinase II from the wheat embryo.     

Thin-layer Chromatography of Triose Reductone and its Relative Compounds

Application of thin-layer chromatographic techniques to the analysis and preparation of triose reductone from naturally occuring reductone compounds has become an important tool in reductone chemistry. A satisfactory method for the separation of triose reductone and related compounds by thin-layer chromatography, using silica gel plate and various solvents as developer, is described. Seven reductones were separated from each other by two-dimensional chromatography.     

曲氏传药中乌头碱的薄层色谱测定

在硅胶Ｇ薄层板上用氯仿：１,２．二氯乙烷：甲醇：氨水（９：１：０．９：０．０７,ｖ／ｖ）为展开剂分离中草药复方曲氏传药中的生物碱,并用改良碘化铀钾试剂显色后对其中的乌头碱进行直接扫描测定。此法简便、快速、准确、灵敏且稳定。     

On the Determination of Mevalonic Acid by Thin-layer and Gas Chromatography

In this paper a new method of chemical determination of mevalonic acid in fermented materials is described. Mevalonic acid is identified as hydroxamate of its lactone using thin-layer chromatography, and is determined quantitatively as lactone-form by gas liquid chromatography. Mevalonic acid separated from kôji extract was identified by analysis of infrared spectrum. Saké and Kôji contained 4.6 μ/ml and 43.3 μ/g of this acid, respectively.     

The Detection of Microbial Spoilage in Canned Foods Using Thin-layer Chromatography

Thin-layer chromatography was investigated as an inexpensive alternative to traditional microbiological techniques for the detection of microbial growth in canned vegetables. It was compared with culture methods, pH determination and direct microscopy in batches of canned vegetables with a known incidence of spoilage.     

A Note on the Separation of Natural Mixtures of Bacterial Ubiquinones using Reverse-phase Partition Thin-layer Chromatography and High Performance Liquid Chromatography

Natural mixtures of bacterial ubiquinones (coenzyme Q) were separated according to the length of the polyisoprenyl side-chain using reverse-phase thin-layer chromatography and high performance liquid chromatography. The chromatographic systems described afford a rapid and sensitive means of ubiquinone characterization.     

Isolation of Indole-3-Acetyl Amino Acids using Polyvinylpolypyrrolidone Chromatography

Amino acid conjugates of IAA can be chromatographed on polyvinylpolypyrrolidone (PVPP) using either acidic methanol or aqueous buffers as eluents. In the aqueous system, elution of the compounds is pH-dependent, and the pattern obtained suggests that hydrophobic interactions contribute substantially to the chromatographic behavior of IAA peptides on PVPP. Purification of soybean seed extracts by PVPP chromatography produced fractions containing indole-3-acetylaspartate and indole-3-acetylglutamate, based on chromatographic and mass spectral analysis, as well as three other indolic compounds, tentatively identified as N-acyl tryptophan derivatives. PVPP chromatography provides an effective preliminary purification of IAA peptides from plant extracts prior to their separation by other techniques such as high performance liquid chromatography.     

Analysis of Fluorescein-thiohydantoin Amino Acids by High Speed Liquid Chromatography

The distribution of choline oxidase activity was studied with cell-free extracts of yeasts, molds and actinomycetes. A fungus which was identified as Cylindrocarpon didymum M–1 showed the highest activity. The enzyme was purified from the cell-free extract of C. didymum M–1 by a procedure involving ammonium sulfate fractionation and DEAE-cellulose, hydroxyl-apatite and Sephadex G–150 column chromatographies. The enzyme preparation was homogeneous when subjected to disc gel electrophoresis and ultracentrifugation. Sedimentation velocity yielded a value of . The enzyme showed a typical flavoprotein spectrum of absorption maxima at 276,370 and 454 nm.     

Determination of Carboxylic Acids in Wines by Liquid Ion-Exclusion Chromatography

The chromatographic behavior of aromatic and aliphatic acids was studied using an ion-exclusive column. The conditions were determined under which the separation of the acids by single-column ion-exclusion chromatography with UV detection was the most selective and efficient. The method developed was employed for determining the content of carboxylic acids in wines.     

A Note on the Separation of Natural Mixtures of Bacterial Menaquinones using Reverse Phase Thin-layer Chromatography

Natural mixtures of bacterial menaquinones were separated according to the length and degree of saturation of the polyisoprenyl side-chain using ready made Merck RP-18F₂₅₄ reverse phase thin-layer chromatography plates. The system described affords a simple and rapid means of menaquinone characterization.     

Determination of Steam-Volatile Organic Acids in Fermentation Media by Gas-Liquid Chromatography

Five gas chromatographic liquid phases (25% Carbowax 20 M plus 4% H₃PO₄, 17.5% dioctyl sebacate plus 7.5% sebacic acid, 17.5% dioctyl sebacate plus 7.5% docosanoic acid, 5% Tween 80, and 20% LAC-296 [poly (diethylene glycol adipate)] plus 2% H₃PO₄) were studied with respect to their utility in the separation and quantitation of steam-volatile organic acids commonly produced in fermentation. Optimal operating conditions and column stability for routine analysis were established. An Aerograph Hy-Fi gas chromatograph was used for all work, except the studies with Tween 80 in which an Aerograph A-90-C was employed. Chromatographic traces are presented of volatile fatty acid analyses with each of the liquid phases. Complete separation of all isomers of the fatty acids from C₂ to C₅ was accomplished by the Carbowax 20 M plus H₃PO₄, dioctyl sebacate plus sebacic acid, and dioctyl sebacate plus docosanoic acid columns. The latter two liquid phases were extremely unstable and proved to be unsatisfactory for analysis of aqueous samples. A column of Carbowax 20 M + H₃PO₄ separated steam-volatile organic acids completely. The volatile fatty acid isomers were separated by 5% Tween 80 somewhat less completely, and the peak shapes were not as sharp and symmetrical as that desired for good quantitative work. LAC-296 (20%) plus 2% H₃PO₄ proved to be the most satisfactory of the liquid phases for routine analysis of deproteinated in vitro rumen fermentation media. The column has been used for routine analysis of rumen fermentation fluid and in vitro rumen incubation fluid. All the organic acids from C₂ to C₅, except isobutyric, could be quantitated with this column. Stability of the column with the aqueous solutions was extremely good. The standard deviation of the analysis of each volatile acid component in a fermentation fluid was less than 0.5 molar per cent. The short-chain organic acids (C₂ to C₅) were shown to be extremely stable in aqueous solution for as long as 6 months after preparation for gas chromatographic analysis by protein precipitation with metaphosphoric acid-H₂SO₄ and refrigeration at 4 C in stoppered tubes.     

反相高效液相色谱法测定烟叶中的游离氨基酸

用不同浓度的乙醇溶液提取烟样中的游离氨基酸 ,结果显示 ,存在最佳的乙醇溶液浓度 ,使烟样中被提取的游离氨基酸总量最大 ;对比了活性炭、乙醚、5 %磺基水杨酸、阳离子交换柱的纯化效果 ,发现阳离子交换柱的纯化效果较其它三种试剂要好。在提取和纯化之后 ,采用OPA、FMOC联合在线衍生反相高效液相色谱法测定了烟样中的游离氨基酸 ,该方法使烟样中的氨基酸和亚氨基酸能被同时测定 ,并且分析方法的重现性和回收率均令人满意。最后用该方法对云南B2 F98(上部、橘黄、二等烟叶 ,98年产 )烟叶中的游离氨基酸进行了测定 ,有 15种氨基酸被测出 ,其中Pro含量最高 ,约占总量的 2 5 % ,Thr含量最低 ,约占总量的 1%。