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: N nanoparticle synthesis by a hitherto unreported actinomycete culture is highlighted, the biomolecule involved in the process is identified and the associated antioxidant activity is described.
64 citations
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TL;DR: In this paper, a reversed phase high performance liquid chromatography has been used and results confirmed for the more concentrated compounds by thin-layer chromatography on silica gel.
64 citations
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TL;DR: X-ray diffraction analysis indicated that the in vitro product is cellulose II, which is in contrast to the in vivo product—namely, cellulose I, and the weight-average and number-average degree of polymerization of the in embryos product were 4820 and 5270, respectively.
Abstract: The cytoplasmic and outer membranes of Acetobacter xylinum (ATCC 53582) were isolated by discontinuous sucrose density ultracentrifugation. Both lysozyme (EC 3.2.1.17) and trypsin (EC 3.4.21.4) were required for efficient crude membrane separation. Primary dehydrogenases and NADH oxidase were used as cytoplasmic membrane markers, and 2-keto-3-deoxyoctulosonic acid was used to identify the outer membranes. Cellulose synthetase (UDP-glucose:1,4-β-D-glucan 4-β-D-glucosyltransferase; EC 2.4.1.12) activity was assayed as the conversion of radioactivity from UDP-[14C]glucose into an alkali-insoluble β-1,4-D-[14C]glucan. This activity was predominantly found in the cytoplasmic membrane. The cellulose nature of the product was demonstrated by (i) enzymatic hydrolysis followed by TLC, (ii) methylation analysis followed by TLC, and (iii) GC/MS. Further, the weight-average and number-average degree of polymerization of the in vitro product, determined by high-performance gel permeation chromatography, were 4820 and 5270, respectively. In addition, x-ray diffraction analysis indicated that the in vitro product is cellulose II, which is in contrast to the in vivo product—namely, cellulose I.
64 citations
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TL;DR: These 32P-postlabeling and nucleotide chromatographic procedures should be useful in monitoring human exposure to methylating and ethylating carcinogens.
Abstract: The 32P-postlabeling procedure, developed originally by Randerath and coworkers, has been modified for the detection and analytical quantitation of O 6-alkyl-2′-deoxyguanosine residues in DNA. Chromatographic techniques were developed to resolve individually the normal deoxyribonucleotide-3′-monophosphates and the O 6-alkyldeoxyguanosine-3′-monophosphates by high-pressure liquid chromatography. Selective deoxyribonucleotide-3′-monophosphates ( e.g. , O 6-alkyldeoxyguanosine-3′-monophosphates) were then converted to labeled deoxyribonucleotide-[5′-32P]monophosphates by 32P-postlabeling and nuclease P1 treatment and separated by two-dimensional thin layer chromatography. The O 6-methyl- and O 6-ethyl-2′-deoxyguanosine-3′-monophosphate nucleotides, and the respective 5′-monophosphates, were chemically synthesized for standardization of these quantitative procedures. The quantitation of O 6-methyl- and O 6-ethyl-2′-deoxyguanosine was observed to be analytically accurate between one O 6-alkyl-2′-deoxyguanosine residue per 104 and 107 2′-deoxyguanosines. The limit of detection was less than one O 6-alkyl-2′-deoxyguanosine in 107 2′-deoxyguanosine residues in a sample size of 100 µg of DNA, i.e. , approximately 10 pg of adduct. The quantitation of O 6-methyl-2′-deoxyguanosine in the liver DNAs of rats treated with [14C-Me] N -nitrosodimethylamine compared well with values obtained by both 14C and high-pressure liquid chromatography coupled with fluorescence detection. Thus, these 32P-postlabeling and nucleotide chromatographic procedures should be useful in monitoring human exposure to methylating and ethylating carcinogens.
64 citations
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TL;DR: It is suggested that the identity of the original unknown methylated residue is δ-N-monomethylarginine, a novel type of protein modification reaction in eukaryotes.
64 citations