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High-performance Thin Layer Chromatography (high-performance + thin_layer_chromatography)
Selected AbstractsChemical fingerprinting of Andrographis paniculata using HPLC, HPTLC and densitometryPHYTOCHEMICAL ANALYSIS, Issue 5 2004Alpana Srivastava Abstract An attempt has been made to develop a method by which to determine the chemical ,ngerprint of Andrographis paniculata (Acanthaceae). High-performance thin layer chromatography (HPTLC) was used to analyse hexane, chloroform, methanol and water extracts of leaves of A. paniculata. A computerised densitometer was applied to the two-dimensional spectrographic image analysis of the HPTLC plates. An HPLC equipped with a photodiode array detector was used for the analyses of these different extracts. The analyses showed that andrographolide and neoandrographolide are absent in the hexane extract but are present in greater amounts in the methanol extract as compared with the other extracts. These chromatograms may serve as a chemical ,ngerprint of the drug A. paniculata for quality control purposes and in the preparation of formulations based on the drug. Copyright © 2004 John Wiley & Sons, Ltd. [source] A sialylation study of mouse brain gangliosides by MALDI a-TOF and o-TOF mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 6 2008Mostafa Zarei Abstract Matrix-assisted laser desorption/ionization (MALDI) process of sialoglycoconjugates is generally accompanied by different levels of cleavage of sialic acid residues and/or by dehydration, and decarboxylation reactions. Quantitative densitometry of the mouse brain ganglioside (MBG) components separated by high-performance thin layer chromatography (HPTLC) and evidenced by orcinol staining was a basis to verify the ganglioside composition pattern with respect to the relative abundances of individual components in the mixture. A systematic mass spectrometry (MS) sialylation analysis has been carried out to evaluate the feasibility of an axial time-of-flight (a-TOF) MS, equipped with a vacuum MALDI source and an orthogonal-TOF (o-TOF) instrument with an ion source operated at about 1 mbar of N2. Besides, the esterification by one methyl group of the carboxyl group in sialic acid to increase the stability of the ganglioside species for MALDI MS analysis has been tested and the yield of intact ganglioside species and of the neutral loss of water and carbon dioxide estimated. For the sialylation analysis of native ganglioside mixtures the MALDI o-TOF analysis with 6-azo-2-thiothymine/diammonium citrate (ATT/DAC) as a matrix appears as an optimal approach for ganglioside profiling. Copyright © 2008 John Wiley & Sons, Ltd. [source] Tea tree oil concentration in follicular casts after topical delivery: Determination by high-performance thin layer chromatography using a perfused bovine udder modelJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2005S.S. Biju Abstract Tea tree oil, a popular antimicrobial agent is recommended for the treatment of acne vulgaris, a disease of the pilosebaceous unit. Tea tree oil formulations (colloidal bed, microemulsion, multiple emulsion, and liposomal dispersion containing 5% w/w tea tree oil) were applied to bovine udder skin. The follicular uptake of tea tree oil upon application was determined by a cyanoacrylate method. Tea tree oil was determined by quantifying terpinen-4-ol content using high-performance thin layer chromatography. The accumulation of tea tree oil in the follicular casts was 0.43,±,0.01, 0.41,±,0.009, 0.21,±,0.006, and 0.16,±,0.005 percentage by weight (milligram oil/gram of sebum plug) for microemulsion, liposomal dispersion, multiple emulsion, and colloidal bed, respectively. This is the first study of its kind to quantify tea tree oil concentration in the follicles. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:240,245, 2005 [source] Quantitative determination of phyllanthin and hypophyllanthin in Phyllanthus species by high-performance thin layer chromatographyPHYTOCHEMICAL ANALYSIS, Issue 6 2006Arvind K. Tripathi Abstract A simple, precise and rapid high-performance thin-layer chromatographic method has been developed for the estimation of phyllanthin (1) and hypophyllanthin (2), the important lignans of Phyllanthus species, especially Phyllanthus amarus. Separation of 1 and 2 was carried out on silica gel 60 F254 layers eluted with hexane:acetone:ethyl acetate (74:12:8), and the analytes were visualised through colour development with vanillin in concentrated sulphuric acid and ethanol. Scanning and quantification of spots was performed at 580 nm. Recoveries of 1 and 2 were 98.7 and 97.3%, respectively. The method was validated and the peak purities and limits of detection and quantification were determined. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||