Germination inhibitors in the pine seed coat

Inhibitors from (Pinus pinea L.) seed coats were separated using paper chromatography, thin layer chromatography, and a Sephadex G-10 column. The inhibitory activity was resolved into several fractions. One of these behaved similarly to abscisic acid. It has exhibed the same properties as ABA in thin-layer chromatography, paper chromatography, and Sephadex G-10 chromatography and in UV absorption and fluorescence spectra. These germination inhibitors, present in the seed coats, are involved in the regulation of P. pinea seed germination.Abbreviations ABA abscisic acid - TLC thin-layer chromatography     

Immunochemical detection of ochratoxin A in black Aspergillus strains

One hundred and fifty-seven strains belonging to Aspergillus section Nigri were tested for ochratoxin A production using three different methods: a relatively new immunochemical method based on an enzyme-linked immunosorbent assay (ELISA), thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The monoclonal antibody-based ELISA technique was successfully used to screen for low levels of ochratoxin A in the black Aspergilli without concentrating the culture filtrates. The results were confirmed by TLC and HPLC analysis and chemical derivatization. These latter methods required concentrated filtrates. Ochratoxin A was detected in the culture filtrates of five of the 12 A. carbonarius strains, none of the 45 A.japonicus strains and three of the 100 isolates in the A. niger aggregate (A. foetidus, A. awamori and A. niger).Abbreviations ELISA enzyme-linked immunosorbent assay - HPLC high-performance liquid chromatography - OA ochratoxin A - TLC thin-layer chromatography     

High-performance thin-layer chromatographic separation of ranitidine hydrochloride and two related compounds

Ranitidine hydrochloride and its two related compounds, used in the USP TLC purity testing of the drug, were separated on a high-performance thin-layer chromatography (HPTLC) RP-18 WF_254S precoated plate using methanol–3% NH₄OH (4:1, v/v) as the mobile phase. The main advantage of the proposed HPTLC system over the USP TLC system for testing the purity of ranitidine is a better and more efficient separation of these three compounds in a shorter time and with less consumption of solvents. The system is promising from the point of view of the development of a new method for the TLC purity testing of ranitidine hydrochloride. A video system was used for imaging thin-layer chromatograms. Direct UV densitometric quantitation of the three compounds and a model for the calculation of analytical performance parameters is presented in the second part of the paper.     

Apical dominance and the levels of indole acetic acid in Phaseolus lateral buds

Combined gas chromatography-mass spectrometry procedures have been used to establish that the indole acetic acid levels of lateral buds from Phaseolus seedlings rise following removal of the shoot apex.Abbreviations GC gas chromatograph - GC-MS combined gas liquid chromatography mass spectrometry - bis-TMS bis-trimethylsilyl - IAA indole acetic acid - MPM multiple-peak monitoring - MS mass spectrometer - GLC gas liquid chromatography - TLC thin-layer chromatography     

Occurrence of menaquinone as the sole isoprenoid quinone in the photosynthetic bacterium Heliobacterium chlorum

Thin-layer chromatography, ultraviolet spectrophotometry, high-performance liquid chromatography, and mass spectroscopy revealed that Heliobacterium chlorum contained menaquinone as the sole quinone with an average amount of 0.35 mol per g dry weight of cells. A menaquinone homologue with nine isoprene units occurred as the major component.Non-standard abbreviations MK-n menaquinone with n isoprene units - TLC thin-layer chromatography - HPLC high-performance liquid chromatography     

Apparent cellulase activity of purified xylanase is due to contamination of assay substrate with xylan

Summary Purified xylanase A ofTrichoderma longibrachiatum was active on one of two carboxymethyl cellulose (CMC) preparations used as cellulase assay substrates. The pattern of enzyme activity, and analysis of the substrate by acid hydrolysis and thin-layer chromatography (TLC) suggested that the enzyme had acted on xylan present in the CMC.     

Leaf structure and cytochemical investigation of secretory tissues in Inula viscosa

Leaves of Inula viscosa have been used in medicine from ancient times. Structures or cells with secreting activity were localized and a spectrum of products was histochemically identified within them. Leaf extracts were investigated with gas chromatography – mass spectrometry (GC-MS) and thin-layer chromatography (TLC). Calluses produced from leaf-cell cultures were also subjected to histochemical reagents and tested with GC-MS and TLC to investigate their secreting ability compared with that in leaves. Little-differentiated callus cells are synthetically active and produce, as do its leaf cells, numerous polar compounds that could be of pharmaceutical interest.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 437–448.     

Long-distance transport of sulfur in Nicotiana tabacum

Sulfur reduction in tobacco plants is a light-enhanced process that predominantly takes place in the leaves rather than the roots. The amount of sulfate reduced in mature leaves can exceed their own requirement and enables an export of reduced sulfur, both basipetal toward the roots as well as acropetal toward the growing parts of the stem. Evidence is presented that translocation of reduced sulfur toward the roots occurs in the phloem. TLC and paper chromatography reveal that glutathione is the main transport form of reduced sulfur in tobacco plants; 67–70% of reduced ³⁵S was confined to glutathione, 27–30% to methionine, and 2–8% to cysteine.Abbreviation TLC thin-layer chromatography     

Computerized analysis of TV images for ultrasensitive monitoring of the reaction of fluorochrome with protein

Preparation of protein-specific fluorescent probes with the desired degree of fluorochrome can be greatly facilitated by a technique that combines thin-layer chromatography (TLC) with quantitative image analysis (QIA). Using TLC/QIA, the investigator can determine the fluorochrome/protein ratio on-line with only a few micrograms of protein as fluorochrome is conjugated to protein. In addition, this technique allows rapid quantitation of dye noncovalently adsorbed to fluorochrome-labeled protein.     

Stationary phase thickness determines the quality of thin-layer chromatography/matrix-assisted laser desorption and ionization mass spectra of lipids

Normal phase thin-layer chromatography (NP TLC) is an established method of (phospho)lipid analysis. The determination of the fatty acyl composition is, however, a more challenging task by NP TLC. The direct coupling of TLC separation with mass spectrometric detection (e.g., matrix-assisted laser desorption/ionization mass spectrometry, MALDI MS), however, enables a detailed characterization of complex lipid mixtures. Here we show that the thickness of the silica gel layer has a considerable effect on the quality of the mass spectra recorded directly from the TLC plate. In particular, the intensity of the matrix background signals can be reduced if “thinner” TLC layers are used.     

Chromophoric determination of putrescine, spermidine and spermine with dabsyl chloride by high-performance liquid chromatography and thin-layer chromatography

A fast and sensitive method for the determination of putrescine, spermidine, spermine and ammonia by high-performance liquid chromatography (HPLC) with dabsyl chloride is described. These compounds are converted to their chromophoric dabsyl derivatives and are separated by a normal-phase chromatographic column (μPorasil, 10 μm) with 2% acetone in chloroform as isocratic mobile phase. The sensitivity of the method is 20 pmoles. The present method was shown to be a straightforward procedure for estimating polyamines in various rat tissues.The chromophoric derivatives of polyamines are also well separated by thin-layer chromatography (TLC) on silica gel, and the combination of the HPLC and TLC procedures provides a reliable method for qualitative and quantitative analysis of polyamines.     

Biotransformation of cannabinoids by a cell suspension culture of Cannabis sativa L

A cell suspension culture of Cannabis sativa L. is able to convert cannabidiol to bound cannabielsoins and delta-9 tetrahydrocannabinol to cannabicoumaronon. The localization and the mechanism of the bioconversion are discussed.Abbreviations CBD cannabidiol - CBE cannabielsoin - CBon cannabicoumaronon - EHHC hexahydrocannabinol epoxide - EtOAc ethyl acetate - FBS Fast Blue B salt - GLC gas-liquid chromatography - THC delta-9 tetrahydrocannabinol - TLC thin-layer chromatography     

Auxin in scapes,flower buds,flowers, and fruits of daffodil (Narcissus pseudonarcissus L.)

Summary Diffusates from flower buds, flower fruits, and scape segments, and extracts of flower stalks of Narcissus pseudonarcissus contain an auxin active in the Avena geo-curvature test. The auxin behaved like indole-3-acetic acid (IAA) in thin-layer chromatography (TLC) with neutral and basic solvents on different adsorbents. After TLC, the auxin of the extracts showed chromogenic reactions identical with those of IAA; in gas-liquid chromatography on two different columns, the purified substance, after methylation, appeared at the retention time of IAA methyl ester. The auxin content of the extracts has been estimated to be equivalent to ca. 10 g IAA kg^–1 fresh weight. Diffusates, collected at the basal end of excised flowering apices and of scape segments at different developmental stages, showed highest auxin activity when collected from old buds and young flowers, and from the basal, rapidly elongating scape regions. The diffusible auxin obtained from scape segments was very likely produced by the segments themselves. Thus, the shoot of Narcissus appears to possess two different sites of auxin production, namely, the apical region represented by the flower bud, the flower or the fruit, and the scape.Abbreviations IAA indole-3-acetic acid - IAA-OMe indole-3-acetic-acid methyl ester - TLC thin-layer chromatography - GLC gas-liquid chromatography     

The relationship between diffusible,extractable and conjugated (base-labile) forms of indole-3-acetic acid in isolated coleoptile tips of Zea mays L.

Isolated, 2.5-mm-long coleoptile tips of Zea mays L. cv. Anjou 210 were analyzed for diffusible and tissue-extractable indole-3-acetic acid (IAA) in comparison with the level of base-labile conjugates at various times after excision. The results indicate that base-labile conjugates of IAA do not serve as major sources of free IAA in maize coleoptile tips.Abbreviations IAA indole-3-acetic acid - TLC thin-layer chromatography     

Analysis of ear sebum of the Syrian hamster (Mesocricetus auratus) reveals pronounced sexual dimorphism

External ear of male and female Syrian hamsters (Mesocricetus auratus) were extracted with hexane and separated by class on thin-layer chromatography (TLC). Separated lipid classes were eluted and saponified, and non-saponifiable lipids further characterized by TLC, gas-liquid chromatography (GLC), UV and IR spectroscopy and functional group analyses. Many sex differences were observed, most notably the presence of sex-specific sterols of males and females. Mature animals were found to have greater quantities of ear sebum, but the characteristic qualitative lipid profiles of each sex were apparent in immature animals.     

Measurement of various polyaromatic hydrocarbons in the urban area of Naples]

In order to investigate the organic compound fraction of the Naples aerosol a chromatographic method was used for the separation and analysis of the polycyclic aromatic (PAH). As a first step a suitable one-step thin-layer chromatography (TLC) separation of the cyclohexane extractable material from airborne particulate was sought. After the TLC separation the concentrated samples were analyzed by reverse-phase liquid chromatography with fluorescence detection. We obtained chromatographic separation of five PAH on the EPA Priority Pollutant List and we determined the concentration of these PAHs present in atmospheric matter.     

A monoclonal antibody to (S)-abscisic acid: its characterisation and use in a radioimmunoassay for measuring abscisic acid in crude extracts of cereal and lupin leaves

A monoclonal antibody produced to abscisic acid (ABA) has been characterised and the development of a radioimmunoassay (RIA) for ABA using the antibody is described. The antibody had a high selectivity for the free acid of (S)-cis, trans-ABA. Using the antibody, ABA could be assayed reliably in the RIA over a range from 100 to 4000 pg (0.4 to 15 pmol) ABA per assay vial. As methanol and acetone affected ABA-antibody binding, water was used to extract ABA from leaves. Water was as effective as aqueous methanol and acetone in extracting the ABA present. Crude aqueous extracts of wheat, maize and lupin leaves could be analysed without serious interference from other immunoreactive material. This was shown by measuring the distribution of immunoreactivity in crude extracts separated by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), or by comparing the assay with physicochemical methods of analysis. Analysis of crude extracts by RIA and either, after TLC purification, by gas chromatography using an electron-capture detector or, after HPLC purification, by combined gas chromatography-mass spectrometry (GC-MS) gave very similar ABA concentrations in the initial leaf samples. However, RIA analysis of crude aqueous extracts of pea seeds resulted in considerable overestimation of the amount of ABA present. Determinations of ABA content by GC-MS and RIA were similar after pea seed extracts had been purified by HPLC. Although the RIA could not be used to analyse ABA in crude extracts of pea seeds, it is likely that crude extracts of leaves of several other species may be assayed successfully.Abbreviations ABA abscisic acid - DW dry weight - FW fresh weight - GC-ECD gas chromatography using an electron capture detector - GC-MS combined gas chromatographymass spectrometry - HPLC high-performance liquid chromatography - McAb monoclonal antibody - PVP soluble polyvinylpyrrolidone - RIA radioimmunoassay - TLC thin-layer chromatography     

Cytokinins in transfer RNA of normal and crown-gall tissue of Vinca rosea

cis-Zeatin riboside was identified in transfer-RNA hydrolysates from both normal and crown-gall tissue of Vinca rosea L. The trans-isomer was associated exclusively with the crowngall transfer-RNA. The importance of these observations is discussed in relation to biosynthesis of free cytokinins.Abbreviations GC-MS gas chromatography-mass spectrometry - HPLC high-performance liquid chromatography - TLC thin-layer chromatography - TMSi trimethylsilyl - tRNA transfer RNA - ZR zeatin riboside     

Biological treatment of oil-contaminated sand: comparison of oil degradation based on thin-layer chromatography/flame ionization detector and respirometric analysis

Oil biodegradation in oil-contaminated sand was simultaneously measured by respirometric and thin-layer chromatography/flame ionization detector (TLC/FID) methods. Degradation rate of 10–32 mg-C kg sand^–1 day was achieved by amending the sand with inorganic nutrients and an oil-degrading yeast. The amendment also increased the initial CO₂ production rate by 5–15 folds, which was not detected by the TLC/FID analysis. However, it was possible to monitor the accumulation of resin/asphaltene fraction up to 130% by the TLC/FID analysis during the oil degradation.     

Identification of l-iduronic acid as a constituent of the major extracellular polysaccharide produced by Butyrivibrio fibrisolvens strain X6C61

Abstract Butyrivibrio fibrisolvens strain X6C61 produces two extracellular polysaccharides (EPS-I and EPS- II) separable by anion-exchange chromatography. The neutral sugar constituents of EPS-I were identified by gas-liquid chromatography (GLC) as the alditol acetates of rhamnose, mannose, galactose, glucose, and an unidentified component. These results were confirmed using thin-layer chromatography (TLC). Neutral sugar analysis of EPS-II, which eluted from DEAE-Sephadex at 0.4 M NaCl, yielded the alditol acetates of rhamnose, galactose, glucose, and idose. However, idose was not found when hydrolysates of EPS-II were analysed by TLC. Further investigations showed that the iditol hexaacetate detected via GLC was an artifact of the commonly-used procedures for neutral sugar analysis. This compound was instead generated from l -iduronic acid, as shown by GLC-MS studies.