Topic
Thin-layer chromatography
About: Thin-layer chromatography is a research topic. Over the lifetime, 7494 publications have been published within this topic receiving 124179 citations. The topic is also known as: TLC.
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TL;DR: Thai propolis contains a promising antibacterial agent against Gram+ve (Staphylococcus aureus and Paenibacillus larvae) and Gram-ve (Escherichia coli) bacteria.
Abstract: Background: Propolis is a sticky, dark brown resinous residue made by bees that is derived from plant resins. It is used to construct and repair the nest, and in addition possesses several diverse bioactivities. Here, propolis from Apis mellifera from Nan province, Thailand, was tested for antibacterial activity against Gram+ve (Staphylococcus aureus and Paenibacillus larvae) and Gram-ve (Escherichia coli) bacteria.
Materials and methods: The three bacterial isolates were confirmed for species designation by Gram staining and analysis of the partial sequence of 16S rDNA. Propolis was sequentially extracted by methanol, dichloromethane and hexane. The antibacterial activity was determined by agar well diffusion and microbroth dilution assays using streptomycin as a positive control. The most active crude extract was further purified by quick column and adsorption chromatography. The apparent purity of each bioactive fraction was tested by thin layer chromatography. The chemical structure of the isolated bioactive compound was analyzed by nuclear magnetic resonance (NMR).
Results: Crude methanol extract of propolis showed the best antibacterial activity with a minimum inhibition concentration (MIC) value of 5 mg/mL for S. aureus and E. coli and 6.25 mg/mL for P. larvae. After quick column chromatography, only three active fractions were inhibitory to the growth of S. aureus and E. coli with MIC values of 6.25 and 31.3 µg/mL, respectively. Further adsorption chromatography yielded one pure bioactive fraction (A1A) with an IC50 value of 0.175 µg/mL for E. coli and 0.683 µg/mL for P. larvae, and was determined to be cardanol by NMR analysis. Scanning and transmission electron microscopy analysis revealed unusual shaped (especially in dividing cells), damaged and dead cells in cardanol-treated E. coli.
Conclusion: Thai propolis contains a promising antibacterial agent.
37 citations
TL;DR: It is proposed that there are several new, undescribed neuraminic acids in the jelly coat of the eggs of the sea urchin, since the sialic acid yielded only 45% of the color in the reaction with thiobarbituric acid as compared with the direct Ehrlich assay and, moreover, no release of sIALic acid from the complex by neuraminidase treatment was obtained.
37 citations
TL;DR: The best combination of the chromatographic systems examined for the identification of an unknown compound is G LC on OV-17, HPLC on ODS-Hypersil with acetonitrile-water as eluent and TLC using an isooctane-ethyl acetate solvent system.
37 citations
TL;DR: This paper shows how to perform mono and two-dimensional thin layer chromatography of the total lipid mixture extracted from mouse brains and, in a few cases, from cells in culture.
Abstract: Thin layer chromatography is the easiest way to analyze the total glycosphingolipid mixtures extracted, and, in some cases, partially purified from tissues and cultured cells. Several solvent systems have been introduced to separate the complex mixtures as a function of their composition, presence of contaminants and, in some cases, of their quantity. In addition, colorimetric, enzymatic, immunological and radiochemical detection procedures are available for their recognition. The method does not allow to determine the chemical structure of separated molecules, but gives a very economical and very accessible first information on their possible structure on the basis of their chromatographic mobility in comparison with standards, and of their reactivity to the staining procedures. In this paper we show how to perform mono and two-dimensional thin layer chromatography of the total lipid mixture extracted from mouse brains and, in a few cases, from cells in culture. Table 1 shows the structures of reported lipids.
37 citations
TL;DR: A rapid and simple method for identifying 25 commonly used organophosphorus insecticides in human serum using high-performance thin-layer chromatography (HPTLC) and sensitivities may be sufficient to detect those organoph phosphates in patient serum after acute poisoning.
37 citations