Showing papers on "Thin-layer chromatography published in 2013"
TL;DR: In this paper, the use of liquid dimethyl ether (DME) as a solvent for extracting hydrocarbons and lipids from Botryococcus braunii Race B paste was proposed.
64 citations
TL;DR: Under the optimal conditions, the limit of detection of ferulic acid was found to be 1 ppm and 7 ppm (S/N = 3) for first and second designs, respectively, with good agreement with the standard HPLC-UV detection method.
Abstract: Ferulic acid is an important phenolic antioxidant found in or added to diet supplements, beverages, and cosmetic creams. Two designs of paper-based platforms for the fast, simple and inexpensive evaluation of ferulic acid contents in food and pharmaceutical cosmetics were evaluated. The first, a paper-based electrochemical device, was developed for ferulic acid detection in uncomplicated matrix samples and was created by the photolithographic method. The second, a paper-based colorimetric device was preceded by thin layer chromatography (TLC) for the separation and detection of ferulic acid in complex samples using a silica plate stationary phase and an 85:15:1 (v/v/v) chloroform: methanol: formic acid mobile phase. After separation, ferulic acid containing section of the TLC plate was attached onto the patterned paper containing the colorimetric reagent and eluted with ethanol. The resulting color change was photographed and quantitatively converted to intensity. Under the optimal conditions, the limit of detection of ferulic acid was found to be 1 ppm and 7 ppm (S/N = 3) for first and second designs, respectively, with good agreement with the standard HPLC-UV detection method. Therefore, these methods can be used for the simple, rapid, inexpensive and sensitive quantification of ferulic acid in a variety of samples.
59 citations
01 Jan 2013
TL;DR: In this article, two bioactive polyphenolic compounds from methanol extract of Azolla microphylla and their subsequent characterization were identified as rutin and quercetin.
Abstract: Objective: The present study was designed for isolation of bioactive polyphenolic compounds from methanol extract of Azolla microphylla and their subsequent characterization. Methods: The flavonoid compounds were isolated and characterized by using thin layer chromatography (TLC), purified by preparative thin layer chromatography (PTLC) and were identified using High performance chromatography (HPLC). Their structures and chemical bonds were analyzed using Ultraviolet-Visible spectrophotomery (UV spec), Fourier Transform-Infra Red spectroscopy (FTIR) and Nuclear magnetic resonance NMR (13C and 1H) techniques. Results: Two flavonoids were identified as rutin and quercetin. The isolated compounds showed a potent antioxidant radical scavenging activity, as assessed by non-physiological assays like DPPH (2, 2-diphenyl-1-picrylhydrazyl), ABTS (2, 2’-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt) and FRAP (Ferric reducing antioxidant power). Conclusion: For the first time rutin and quercetin have been isolated successfully from the macrophyte aquatic fern Azolla microphylla under the present study. The isolation of the above characterized flavonoids would be useful to prepare plant-based pharmaceutical preparation to treat various complications linked with human diseases.
57 citations
TL;DR: A simple, rapid and reliable TLC-DPPH˙ test with image processing has been developed enabling comparison of free radical scavenging activity of plant polyphenols and it has been discovered that acylation of flavonoid glycosides with hydroxycinnamic acids increases their direct anti-oxidant properties.
Abstract: Introduction
The structure of polyphenolic compounds influences their anti-oxidant potential. Finding a simple, rapid and reliable analytical method to study the structure–activity relationships for numerous samples is challenging.
Objective
To develop a simple thin-layer chromotography–2,2-diphenyl-1-picrylhdrazyl (TLC–DPPH˙) protocol with image processing to study the influence of the structure of polyphenols on observed direct anti-oxidant properties.
Methodology
First, compounds exhibiting free radical scavenging activities were chosen from among the isolated compounds with the application of a rapid TLC dot-blot test. The active ones were further chromatographed on silica gel plates using the mobile phase: acetonitrile:water:chloroform:formic acid (60:15:10:5, v/v/v/v). Subsequently the plates were stained with DPPH˙ methanolic solution. An improved image processing protocol was used to quantitatively measure the polyphenols’ activity.
Results
The application of a properly optimised chromatographic system enabled separation of the investigated compounds from dimethyl sulphoxide (DMSO) that influences the results of an anti-oxidant test. New solutions enabling better data processing are proposed. It has been discovered that acylation of flavonoid glycosides with hydroxycinnamic acids increases their direct anti-oxidant properties. Some of the analysed glycosides acylated with ferulic acid molecule were found to be the most potent free radical scavengers from among those analysed. The amount of sugar moieties as well as their type also influenced the observed activity.
Conclusion
A simple, rapid and reliable TLC–DPPH˙ test with image processing has been developed enabling comparison of free radical scavenging activity of plant polyphenols. The influence of different structural features on the observed activity was measured successfully. Copyright © 2012 John Wiley & Sons, Ltd.
43 citations
TL;DR: The results indicated that the enzyme was specific of the β-1,4 linkage and hydrolyzed κ-carrageenan into λ-neocarraoctaose-sulfate and κ -neoccarrahexaose-Sulfate first, and then broke κ
Abstract: A carrageenan-degrading marine Cellulophaga lytica strain N5-2 was isolated from the sediment of carrageenan production base. A κ-carrageenase (EC 3.2.1.83) with high activity was purified to electrophoretic homogeneity from the culture supernatant by a procedure of ammonium sulfate precipitation, dialyzing and gel filtration on SephadexG-200 and SephadexG-75. The purified enzyme was verified as a single protein on SDS-PAGE, and whose molecular weight was 40.8 kDa. The κ-carrageenase yielded a high activity of 1170 U/mg protein. For κ-carrageenase activity, the optimum temperature and pH were 35 °C and pH 7.0, respectively. The enzyme was stable at 40 °C for at least 2.5 h. The enzyme against κ-carrageenan gave a Km value of 1.647 mg/mL and a Vmax value of 8.7 μmol/min/mg when the reaction was carried out at 35 °C and pH 7.0. The degradation products of the k-carrageenase were analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), electrospray ionization time-of-flight mass spectroscopy (ESI-TOF-MS) and 13C-NMR spectroscopy, and the results indicated that the enzyme was specific of the β-1,4 linkage and hydrolyzed κ-carrageenan into κ-neocarraoctaose-sulfate and κ-neocarrahexaose-sulfate first, and then broke κ-neocarraoctaose-sulfate into κ-neocarrabiose-sulfate and κ-neocarrahexaose-sulfate.
39 citations
TL;DR: Th Thin layer chromatography is used by many industries and fields of research, including pharmaceutical production, clinical analysis, industrial chemistry, environmental toxicology, food chemistry, water, inorganic, and pesticide analysis, dye purity, cosmetics, plant materials, and herbal analysis.
Abstract: In many experiments, it is important to be able to separate a mixture into its chemical components in order to isolate one compound or to assess the purity of the mixture. Thin layer chromatography (TLC) is one of the easiest and most versatile methods of doing this because of its low cost, simplicity, quick development time, high sensitivity, and good reproducibility. TLC is used by many industries and fields of research, including pharmaceutical production, clinical analysis, industrial chemistry, environmental toxicology, food chemistry, water, inorganic, and pesticide analysis, dye purity, cosmetics, plant materials, and herbal analysis. In its simplest form, glass plates are coated with a uniform layer of silica gel (SiO2). The dissolved sample is placed on the plate, and the plate is inserted into a screw-top jar containing the developing solvent and a piece of filter paper. When the solvent has risen to near the top of the plate, the plate is removed, dried, and visualized using UV light. Variations on this protocol are used for different purposes, including pretreating the sample, changing the sorbent, plate material, the solvent system, the development techniques, and method of detection and visualization or by coupling TLC to other techniques.
34 citations
TL;DR: An integrated high-throughput strategy to extensively screen γ-PGA-producing bacteria with high yield and different molecular weight was developed, comparable to that of high-performance liquid chromatography and gel permeation chromatography assay.
Abstract: Poly(γ-glutamic acid) (γ-PGA) is a promising biomaterial with a wide range of unique applications. To extensively screen γ-PGA-producing bacteria with high yield and different molecular weight, we developed an integrated high-throughput strategy. Firstly, γ-PGA-producing bacteria were selected in a primary screen plate containing a basic dye (neutral red) based on the concentric zone formed through the electrostatic interaction between the dye and the secreted acidic polymer γ-PGA. Then, the isolates were cultured in 50 ml tubes instead of 250 ml flasks. A good correlation of fermentation results in 50 ml tubes and 250 ml flasks was observed. Thirdly, the γ-PGA yield and weight-average molecular weight (M (w)) were simultaneously determined by spectrophotomic assay (UV assay) and neutral red plate assay. The results showed that the diameter of the concentric zone varied among isolates and was negatively correlated with the weight-average molecular weight of γ-PGA. The accuracy of the methods was comparable to that of high-performance liquid chromatography and gel permeation chromatography assay. Lastly, γ-PGA obtained from the target isolates was rapidly identified using thin layer chromatography assay. With this strategy, 13 bacteria with high yield and various molecular weights of γ-PGA from 500 obvious single colonies on the primary screen plate were obtained.
34 citations
TL;DR: The efficiency on PVA plate was greatly improved compared to the efficiency on Si-Gel HPTLC plate and the hydrolysis products of aspartame in diet coke, aspartic acid and phenylalanine, were also successfully analyzed using PVA-UTLC plate.
34 citations
TL;DR: The obtained results show that reversed-phase chromatography (experimental parameters) may be a good instrument for analytics in describing the lipophilic nature of investigated compounds as well as the activity.
31 citations
TL;DR: Thin-layer chromatography — direct bioautography against Escherichia coli and Bacillus subtilis was used for detection of antibacterial activity of the plant extracts and essential oils and the bioautographic fingerprints were compared with the fingerprints obtained after derivatization with anisaldehyde.
Abstract: The main volatile compounds from three medicinal plants belonging to Lamiaceae family were screened for their biological properties. The plants were Salvia officinalis, Thymus vulgaris, and Mentha × piperita containing as the main volatile constituents thujone, thymol, and menthol, respectively. The applied chromatographic system was silica gel developed with toluene-ethyl acetate (93:7). Thin-layer chromatography — direct bioautography (TLC-DB) against Escherichia coli and Bacillus subtilis was used for detection of antibacterial activity of the plant extracts and essential oils. The bioautographic fingerprints were compared with the fingerprints obtained after derivatization with anisaldehyde.
27 citations
Journal Article•
TL;DR: In this article, the authors explored potential solvents for chromatography that are more amenable to separation and recovery by distillation and found that the greater eluotropic strength and especially the transparent short-wavelength UV window of acetone provide additional advantages over the commonly used ethyl acetate.
Abstract: Solvents used in chromatographic purification of intermediates and products are a major source of waste and expense in synthetic research and synthetic processes. The ethyl acetate–hexane mixtures most commonly used for flash chromatography on silica gel are not readily separable by distillation due to their similar boiling points and azeotrope formation. Potential solvents for chromatography that are more amenable to separation and recovery by distillation were thus explored. Acetone–heptane mixtures were found to be convenient and sufficiently separable for routine use and recovery for organic separations. The greater eluotropic strength and especially the transparent short-wavelength UV window of acetone provide additional advantages over the commonly used ethyl acetate. The recycling of solvents from chromatography can greatly reduce the volume of waste generated by synthetic laboratories while also reducing operating costs.
TL;DR: The presented results confirm that imidazolium tetrafluoroborate ionic liquids are efficient suppressors of free silanols, which are considered to be responsible for troublesome and irreproducible chromatographic determinations of basic compounds.
Abstract: A specific and reliable high-performance thin layer chromatography method with densitometry detection has been developed for the de- termination of naphazoline nitrate in nasal drops. The best separ- ation of the basic analyte, without spot tailing, was achieved by using a mobile phase composed of acetonitrile -water (60:40, v/v), adding 1.5 % (v/v) imidazolium-class ionic liquid and covering the plates with a stationary phase based on RP-18 with F254S (10 3 20 cm). The presented results confirm that imidazolium tetrafluoro- borate ionic liquids are efficient suppressors of free silanols, which are considered to be responsible for troublesome and irreproducible chromatographic determinations of basic compounds. The devel- oped chromatographic system was found to be convenient in use and to provide a repeatable assay of naphazoline nitrate in nasal drops, which could not be obtained with the use of standard silanol suppressing mobile phase additives such as triethylamine or dimethyloctylamine. the ILs based on the BF4 ,C l 2 and MeSO4 anions are water- stable compounds, which dissolve in typical chromatographic mobile phases. Recently, ILs have been proposed as silanol suppressing agents (15, 16). The significant effects of imidazolium-based ILs as mobile phase modifiers in thinlayer chromatography (TLC) and high-performance liquid chromatography (HPLC) on the retention of basic compounds have been studied and described elsewhere (13). The addition of 0.5 -2.5% (v/v) of some types of ILs composed of 1,3-dimethylimidazolium, 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-octyl-3-methylimidazolium or 1-butyl-4-methylpyridinium cations and bromide chlorate, hexafluorophosphate, methyl sulphate, tetrafluoroborate or tosylate anions more markedly
TL;DR: The hexane extract of Curcuma aromatica, a plant belonging to the family Zingiberaceae was tested on 10 bacterial strains and found to be active against all Gram-positive strains tested, but inactive against Gram-negative strains.
Abstract: The hexane extract of Curcuma aromatica, a plant belonging to the family Zingiberaceae was tested on 10 bacterial strains (clinical isolates and standard strains). Agar diffusion method was adopted for determining the antibacterial activity of the extract. The hexane extract was found to be active against all Gram-positive strains tested, but inactive against Gram-negative strains. The minimum inhibitory concentration and minimum bactericidal concentration were determined and found to be 539 μg/ml. The phytochemical analysis of hexane extract by gas chromatography mass spectrometry revealed the presence of 13 compounds. The crude hexane extract was partially purified by thin layer chromatography. The zone showing good antibacterial activity was analysed further by gas chromatography mass spectrometry, UV/Vis spectrophotometry and Fourier transform infrared spectroscopy, which indicated the probable presence of germacrone.
TL;DR: A new comprehensive TLC×MS procedure for screening flavanols in the entire chromatogram was developed as an alternative to the use of 4-dimethylaminocinnamaldehyde to determine the locations of compounds on the plate.
TL;DR: This work shows, that at low or high concentration of water in the mobile phase comprised methanol and some additives the chromatographic systems with the plates mentioned demonstrate normal- or reversed-phase liquid chromatography properties, respectively, for separation of peptides obtained.
TL;DR: A protocol for membrane lipid quantification is presented starting with the separation via TLC, transmethylation of the isolated lipids to fatty acid methyl esters, and their quantitative analysis via gas chromatography (GC).
Abstract: Galactolipids represent the predominant membrane lipid class in plants. In general, galactolipids are restricted to plastids, but during phosphate deficiency, they also accumulate in extraplastidial membranes. Two groups of plants can be distinguished based on the presence of a specific fatty acid, hexadecatrienoic acid (16:3), in chloroplast lipids. Plants that contain galactolipids with 16:3 acids are designated "16:3-plants"; the other group of plants which lack 16:3 contain mostly 18:3 in their galactolipids ("18:3-plants"). The methods in this chapter describe the extraction of membrane lipids from whole leaves, or from subcellular fractions, and their analysis via thin-layer chromatography (TLC) with different staining methods. Furthermore, a protocol for membrane lipid quantification is presented starting with the separation via TLC, transmethylation of the isolated lipids to fatty acid methyl esters, and their quantitative analysis via gas chromatography (GC).
TL;DR: An optimized protocol for the steady state labeling, separation, and quantification of yeast phospholipids using 1-D TLC is described.
Abstract: Thin-layer chromatography (TLC) is a technique that has been routinely used for the separation and identification of lipids. Here we describe an optimized protocol for the steady state labeling, separation, and quantification of yeast phospholipids using 1-D TLC.
Journal Article•
TL;DR: In this paper, a study was conducted for isolation of Pseudomonas fluorescence from rhizosphere soil, production, optimization and characterization of indole acetic acid utilizing the isolated bacteria.
Abstract: The present study was undertaken for isolation of Pseudomonas fluorescence from rhizosphere soil, production, optimization and characterization of indole acetic acid utilizing the isolated bacteria. The isolate was identified as Pseudomonas fluorescence by 16S rRNA gene sequencing after following the conventional biochemical tests as per Bergey’s manual of systematic Bacteriology. Cultural and nutritional conditions were optimized for indole acetic acid production. The effect of L-tryptophan was studied and the highest yield of 58 µg/ml on 72 hr was obtained using 0.5mg/ml concentration. The effect of various carbon sources such as lactose, galactose, sucrose, cellulose and mannitol was studied. The best yield of 53 µg/ml was obtained with medium supplemented 1% lactose. The effect of nitrogen source was studied by adding soyabean, beefextract, yeast extract, peptone and tryptone. The maximum yield of 48 µg/ml was obtained with supplemented 0.2% peptone as an organic nitrogen source. The IAA produced was subjected to thin layer chromatography for further identification and quantitative estimation was done by high pressure liquid chromatography. The compound was purified and identified as IAA by GC-MS. The result suggests that Pseudomonas fluorescence possess plethora of mechanisms to stimulate plant growth and worth applying these bacteria in agriculture.
TL;DR: The main aim of as discussed by the authors is chromatographic analysis of red pigment in different well known and local brands of lipsticks, which can be used as unique feature to distinguish among lipstick sources.
Abstract: The main aim of present work is chromatographic analysis of red pigment in different well known and local brands of lipsticks. Lipstick samples of different brands of similar color were selected for this study. Coloring agent was analyzed by thin layer chromatography (TLC). Using different solvent systems [Toluene/Benzene] (4:12), Toluene/Benzene/Cyclohexane (4:12:4), Toluene/Benzene/Diethyl ether (4:4). It is hypothesized that through thin layer chromatography analysis of the red pigment in these different brands will provide no characteristic data to distinguish among lipstick sources. There is no significant difference in the hRf values among the local and well known brands of lipsticks which can be used as unique feature.
TL;DR: Evidence is provided that the maximum parasitic activity of ethyl acetate extract and a synergistic effect of combinations of different compounds have been suggested and a novel, targeted, simple, and eco-friendly approach has been suggested to control blood-feeding parasites.
Abstract: Ticks and mosquitoes are ectoparasitic arthropods that can transmit a variety of diseases to humans and animals during blood feeding and causing serious infectious disorders. The purpose of the present study was to assess the acaricidal and insecticidal property of ethyl acetate extract and its compounds isolated from marine actinobacteria, Streptomyces VITSTK7 sp. against the larvae of cattle ticks, Haemaphysalis bispinosa and Rhipicephalus (Boophilus) microplus (Acari: Ixodidae); fourth-instar larvae of malaria vector, Anopheles subpictus; and filarial vector, Culex quinquefasciatus (Diptera: Culicidae). The ethyl acetate extract was loaded on silica gel column and separated with chloroform, methanol, and acetone as the solvents system. The separation of fractions was visualized by the thin layer chromatography (TLC) plate, further confirmed by high-performance liquid chromatography, and followed by gas liquid chromatography. Three major fractions were analyzed in mass spectroscopy (MS) and matched with existing compounds in the data base. Based on the fragment pattern, it led to the major compounds which were predicted as cyclopentanepropanoic acid, 3,5-bis(acetyloxy)-2-[3-(methoxyimino)octyl], methyl ester (13.3 %) 1; 5-azidomethyl-3-(2-ethoxy carbonyl-ethyl)-4-ethoxycarbonylmethyl-1H-pyrrole-2-carboxylic acid, ethyl ester (18.2 %) 2; and akuammilan-16-carboxylic acid, 17-(acetyloxy)-10-methoxy, methyl ester (16R) (53.3 %) 3. The maximum efficacy was observed in compounds 1, 2, and 3, and the ethyl acetate extract of Streptomyces VITSTK7 sp. against the larvae of H. bispinosa (LC(50) = 1,573.36, 1,333.09, 1,073.29, and 409.71 ppm; r(2) = 0.0.990, 0.934, 0.935, and 0.908), R. microplus (LC(50) = 1,877.86, 815.83, 1,631.14, and 441.54 ppm; r(2) = 0.981, 0.926, 0.0970, and 0.915), A. subpictus (LC(50) = 273.89, 687.69, 464.75, and 223.83 ppm; r(2) = 0.758, 0.924, 0.841, and 0.902), and C. quinquefasciatus (LC(50) = 430.06, 881.59, 777.0, and 195.70 ppm; r(2) = 0.839, 0.859, 0.870, and 0.882), respectively. Results of the present study provide evidence that the maximum parasitic activity of ethyl acetate extract and a synergistic effect of combinations of different compounds have been suggested. The control (distilled water) showed nil mortality in the concurrent assay. In the present study, a novel, targeted, simple, and eco-friendly approach has been suggested to control blood-feeding parasites.
TL;DR: In this article, a thin layer chromatography method was developed to estimate the lipophilicity of purine derivatives from the calibration curve, and the most lipohilic compound was methylazathioprine (0.64).
Abstract: Mercaptopurine and its derivatives are used in the treatment of leukemia. To estimate their lipophilicity, a simple and novel thin layer chromatography method was developed. The mobile phase was the mixture of acetonitrile and water. The acetonitrile content varied by 5% from 50% to 80%. The linear relationship between log𝑃 and 𝑅𝑚0 for substances with known lipophilicity was found. The lipophilicity of purine derivatives was worked out from the calibration curve. The most lipohilic compound was methylazathioprine (0.64).
TL;DR: Streptomyces sp.
Abstract: Extraction of pigments from natural sources is gaining momentum due to many biological applications. The aim of our study was to extract and to identify the pigment produced by Streptomyces species isolated from saltpan soil samples. The pigment-producing isolate was characterized by molecular taxonomy, identified as Streptomyces species, and designated as Streptomyces sp. VITVSK1. The isolate produced green color pigmentation upon solid substrate fermentation using parboiled rice as a media for 7 days at 37°C. The pigment derivative was extracted using methanol as solvent and purified by silica gel column chromatography and preparative thin layer chromatography using chloroform: methanol as solvent system. The purified compound was identified as 2,5-di-tert-butyl-1,4-benzoquinone (DTBBQ) based on similarity index with reference compounds available in the mass spectra library, NIST. Structure of the pure compound was also elucidated by 1H and 13C nuclear magnetic resonance spectra. The compound DTBBQ showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with IC50 value of 0.6 μg/mL. DTBBQ also showed antimicrobial activity with a zone of inhibition of 21 mm against Bacillus cereus. The results of the present study showed that Streptomyces sp. VITVSK1 could be a promising source for the production of biologically active quinone-based pigments.
TL;DR: In this article, the root bark of Synadenium glaucescens was extracted using the Soxhlet method using dichloromethane, hexane and petroleum ether, respectively, followed by ethanol.
Abstract: Optimization of extraction conditions and phytochemical screening of the root bark of Synadenium glaucescens were carried out in a stepwise manner in order to obtain the highest yields and the constituents of the extracts. Sequential extraction using Soxhlet method was performed using dichloromethane, hexane and petroleum ether, respectively, each followed by ethanol. Extraction conditions included: running time of 2 to 6 hours, temperature at 25 o C to 95 o C and particle size ranging from 0.4mm to >3mm diameter. Phytochemical screening was done using derivatisation techniques, gas chromatography-mass spectrometry and high performance liquid chromatography. Extraction with dichloromethane followed by ethanol resulted in a higher yield by 25%, within 4 hrs of extraction, particle size of 1mm, at temperatures of 30 o C for dichloromethane and 75 o C for ethanol. Fatty acid analysis indicated absence of free fatty acids in both Dichloromethane and ethanolic extracts. Silylation and Thin Layer Chromatography indicated the presence of non hindered and hindered functionality and the presence of triterpenoids in the dichloromethane extract. Phytochemical screening of the dichloromethane extracts indicated that it is composed of two main triterpenoids that best matched with Lanosterol (42%) and Cycloartenol (31%). Other minor compounds identified through chromatographic analysis were phytol, ergostadiol, hentriacontane, sitastirol aceate, lupeol and hopenone. The ethanolic extracts indicated the presence of polyphenolic compounds.
TL;DR: A nanomaterial-assisted method that combines thin layer chromatography (TLC) with matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) was developed to directly monitor chemical transformations and was successfully used in the natural product discovery of anti-inflammatory flavonoids from Helminthostachys zeylanica, a traditional Chinese herb.
Abstract: A nanomaterial-assisted method that combines thin layer chromatography (TLC) with matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) was developed to directly monitor chemical transformations. A substrate-dependent extraction strategy was studied and successfully used to identify target molecules from the depths of a developed TLC plate. By using this strategy, a hydrophobic sample of interest was enriched on the surface of the TLC plate in the presence of acetonitrile, in contrast to using water and methanol to identify hydrophilic samples. The successful enrichment of samples by specific solvents provided stable desorption/ionization efficiencies of compounds of interest and led to very good sensitivity near the attomole scale. The method was then used to monitor 4-dimethylaminopyridine (DMAP)-catalyzed acylation in preparation of bifunctional sulfonamides. The labile DMAP-acyl intermediate and final sulfonamide product were clearly identified on TLC plates without external purification or sample preparation. Furthermore, in combination with collision-induced dissociation (CID) to provide structural information, the technique was successfully used in the natural product discovery of anti-inflammatory flavonoids from Helminthostachys zeylanica, a traditional Chinese herb. The newly proposed method provides a very low background from silica supports or organic matrices in the low molecular weight range (100–1000 Da). The technique may greatly accelerate studies of metabolomics, drug discovery, and organic synthesis.
01 Jan 2013
TL;DR: Qualitative and quantitative analysis of 6-gingerol in different parts (in vivo and in vitro) of Zingiber officinale using thin layer chromatography (TLC) and high performance liquid Chromatography (HPLC) have been performed.
Abstract: Ginger (Zingiber officinale Rosco) belonging to the family Zingiberaceae is one of the world's most important spices and produces a pungent, aromatic rhizome that is valuable all over the world. Qualitative and quantitative analysis of 6-gingerol in different parts (in vivo and in vitro) of Zingiber officinale using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) have been performed. Data of TLC showed spots having identical Rf value (0.15), according to the synthetic standards of 6-gingerol in all samples extract. 6-gingerol was detected in all extracts of different parts of ginger derived from in vivo and in vitro culture conditions. Quantitative determination of 6-gingerol using HPLC technique was carried out. Comparing with the peaks of 6-gingerol in synthetic standards, in vivo rhizomes and in vitro cultures of different ginger parts was showed similar UV spectra characteristics. The quantity of 6-gingerol in rhizomes (in vivo and in vitro) and in vitro microrhizomes (45.37; 42.64; 28.11 mg/g respectively), were showed a higher value than that of in vitro calli, shoots and roots (7.89; 7.46; 6.40 mg/g respectively).
01 Mar 2013-Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes
TL;DR: Techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative and quantitative determination, and preparative isolation of pesticides and their metabolites and some related pollutants are reviewed.
Abstract: Techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative and quantitative determination, and preparative isolation of pesticides and their metabolites and some related pollutants are reviewed for the period from November 1, 2010 to November 1, 2012. Analyses are described for a variety of samples types and pesticide classes. In addition to references on residue analysis, studies such as pesticide structure - retention relationships, identification and characterization of natural and synthesized pesticides, metabolism, degradation, mobility, lipophilicity, and mechanism of action are covered.
TL;DR: Agarwood leaves are consumed as a healthy tea in Thailand and Taiwan as discussed by the authors, and the MeOH extract of its rhizomes was subjected to solvent partitioning and chromatographic separation to afford eight pure substances.
Abstract: Agarwood (Aquilaria sinensis), well known as an incense in Southeast Asia, has been used as a sedative, analgesic, and digestive aid in traditional medicine. Agarwood leaves are consumed as a healthy tea in Thailand and Taiwan. [1]. Previous phytochemical investigation on Chinese eaglewood revealed characteristic sesquiterpenes and chromone derivatives [2–7], but little is known about the chemical constituents of the healthy wood. By investigation of interrelated studies, agarwood has significant anticancer [8], analgesic and anti-inflammatory activities [9], and antidepression activities [10]. These observations provide useful information for potential chemopreventive drug design. The MeOH extract of its rhizomes was subjected to solvent partitioning and chromatographic separation to afford eight pure substances. The chemical constituents in the bark of A. sinensis were separated by column chromatography into eight compounds, including 5-hydroxy-4 ,7-dimethoxyflavone (1) [11], luteolin-7,3 ,4 -trimethyl ether (2) [12], 5,3 -dihydroxy-7,4 -dimethoxyflavone (3) [13], persicogenin (4) [14], genkwanin (5) [15], methylparaben (6) [16], -sitosterol (7), and (+)-syringaresinol (8) [17]. Compounds 1–8 were obtained for the first time from this plant. The bark (3.5 kg) of Aquilaria sinensis was chipped and air dried and extracted repeatedly with MeOH (5 L 4) at room temperature. The combined MeOH extracts (132.8 g) were then evaporated and further separated into three fractions by column chromatography on silica gel (4.7 kg, 70–230 mesh) with gradients of n-hexane–CH2Cl2–acetone–MeOH. Part of fraction 1 (57.3 g) was subjected to silica gel chromatography by eluting with n-hexane–acetone (60:1) enriched with acetone to furnish two further fractions (2-1–2-2). Fraction 2-1 (31.7 g) was further purified on a silica gel column using n-hexane– acetone mixtures to obtain 5-hydroxy-4 ,7-dimethoxyflavone (1) (30.4 mg). Fraction 2-2 (25.6 g) was further purified on a silica gel column using n-hexane–acetone mixtures to yielded luteolin-7,3 ,4 -trimethyl ether (2) (36.9 mg). Part of fraction 2 (64.2 g) was subjected to silica gel chromatography by eluting with n-hexane–acetone (40:1) enriched with acetone to furnish two further fractions (2-1–2-2). Fraction 2-1 (38.2 g) was further purified on a silica gel column using n-hexane–acetone mixtures to obtain methylparaben (6) (34.6 mg). Fraction 2-2 (26 g) was subjected to silica gel chromatography by eluting with CH2Cl2–MeOH (100:1) enriched gradually with MeOH to obtain two fractions (3-2-1–3-2-2). Fractions 3-2-2 (17.5 g) were subjected to further silica gel column chromatography and purified by preparative TLC (thin layer chromatography) to yield 5,3 -dihydroxy-7,4 -dimethoxyflavone (3) (35.2 mg). Part of fraction 3 (82.5 g) was subjected to silica gel chromatography by eluting with CH2Cl2–MeOH (80:1) enriched with MeOH to furnish two fractions (3-1–3-2). Fraction 3-1 (36.5 g) was further purified on a silica gel column using CH2Cl2–MeOH mixtures to obtain persicogenin (4) (28 mg) and genkwanin (5) (24 mg). Fraction 3-2 (46 g) was further purified on a silica gel column using CH2Cl2–MeOH mixtures to obtain -sitosterol (7) (36.2 mg) and (+)-syringaresinol (8) (34.1 mg).
TL;DR: In this paper, a two dimensional planar chromatographic separation of ethinyl steroids on cyanopropyl phase was carried out over a distance of 70mm, where the steroids were catalytically transformed into fluorescent compounds that can be sensitively detected.
Abstract: We present a two dimensional (2D) planar chromatographic separation of ethinyl steroids on cyanopropyl phase. A mixture of nine steroids was separated by using a cyanopropyl-coated silica gel plate (Merck, 1.16464) with the solvent mix of dichloromethane, methanol, cyclohexane (95 + 5 + 60, v/v) in the first direction and with a mixture of water, acetonitrile, ethanol, dioxane, and NH3 (25%) (8 + 2 + 1 + 1 + 0.05, v/v) in the second direction. Both developments were carried out over a distance of 70 mm. The steroids were catalytically transformed into fluorescent compounds that can be sensitively detected. The fluorescence was measured by a simple 8-bit CCD-camera. The range of linearity covers two magnitudes of power using the extended Kubelka-Munk expression for data transformation. This separation method is inexpensive, fast, and reliable and can be used to quantify 17α-ethinylestradiol (EE2) in the effluents of waste water treatment plants at an LOD of 2 ng per spot. Using a solid phase extraction pre...