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Chemical Profiling (chemical + profiling)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Application of HPLC-NMR for the Rapid Chemical Profiling of a Southern Australian Sponge, Dactylospongia sp.

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 4 2009
Daniel Anthony Dias
Abstract Rapid chemical profiling of the antitumour active crude dichloromethane extract of the marine sponge, Dactylospongia sp. was undertaken. A combination of both offline (HPLC followed by NMR and MS) and on-line (on-flow and stop-flow HPLC-NMR) chemical profiling approaches was adopted to establish the exact nature of the major constituents present in the dichloromethane extract of this sponge. On-flow HPLC-NMR analysis was employed to initially identify components present in the dichloromethane extract, while stop-flow HPLC-NMR experiments were then conducted on the major component present, resulting in the partial identification of pentaprenylated p -quinol (5). Subsequent off-line RP semi-preparative HPLC isolation of 5 followed by detailed spectroscopic analysis using NMR and MS permitted the complete structure to be established. This included the first complete carbon NMR chemical shift assignment of 5 based on the heteronuclear 2-D NMR experiments, together with the first report of its antitumour activity. This study represents one of the few reports describing the application of HPLC-NMR to chemically profile secondary metabolites from a marine organism. [source]

Hypericum perforatum,Chemical profiling and quantitative results of St. John's Wort products by an improved high-performance liquid chromatography method

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2002
M. Ganzera
Abstract The analysis of flavonoids, naphthodianthrones, and the phloroglucinol derivative hyperforin in H. perforatum is described in this article. In a 35-min HPLC run nine major compounds could be identified and baseline separated in the methanolic plant extracts. For an optimum separation the mobile phase consisted of 10 mM ammonium acetate buffer (pH 5.0) and an acetonitrile/methanol mixture; a Synergi MAX-RP 80 Å column (C-12 material) was used as stationary phase. Detection was performed at 270 nm, and the identity of the compounds was confirmed in an LC-MS experiment. Commercial St. John's Wort products were analyzed and qualitative and quantitative results are discussed. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:623,630, 2002 [source]

Application of HPLC-NMR for the Rapid Chemical Profiling of a Southern Australian Sponge, Dactylospongia sp.

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 4 2009
Daniel Anthony Dias
Abstract Rapid chemical profiling of the antitumour active crude dichloromethane extract of the marine sponge, Dactylospongia sp. was undertaken. A combination of both offline (HPLC followed by NMR and MS) and on-line (on-flow and stop-flow HPLC-NMR) chemical profiling approaches was adopted to establish the exact nature of the major constituents present in the dichloromethane extract of this sponge. On-flow HPLC-NMR analysis was employed to initially identify components present in the dichloromethane extract, while stop-flow HPLC-NMR experiments were then conducted on the major component present, resulting in the partial identification of pentaprenylated p -quinol (5). Subsequent off-line RP semi-preparative HPLC isolation of 5 followed by detailed spectroscopic analysis using NMR and MS permitted the complete structure to be established. This included the first complete carbon NMR chemical shift assignment of 5 based on the heteronuclear 2-D NMR experiments, together with the first report of its antitumour activity. This study represents one of the few reports describing the application of HPLC-NMR to chemically profile secondary metabolites from a marine organism. [source]

,13C, ,15N and ,2H isotope ratio mass spectrometry of ephedrine and pseudoephedrine: application to methylamphetamine profiling

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 13 2009
Michael Collins
Conventional chemical profiling of methylamphetamine has been used for many years to determine the synthetic route employed and where possible to identify the precursor chemicals used. In this study stable isotope ratio analysis was investigated as a means of determining the origin of the methylamphetamine precursors, ephedrine and pseudoephedrine. Ephedrine and pseudoephedrine may be prepared industrially by several routes. Results are presented for the stable isotope ratios of carbon (,13C), nitrogen (,15N) and hydrogen (,2H) measured in methylamphetamine samples synthesized from ephedrine and pseudoephedrine of known provenance. It is clear from the results that measurement of the ,13C, ,15N and ,2H stable isotope ratios by elemental analyzer/thermal conversion isotope ratio mass spectrometry (EA/TC-IRMS) in high-purity methylamphetamine samples will allow determination of the synthetic source of the ephedrine or pseudoephedrine precursor as being either of a natural, semi-synthetic, or fully synthetic origin. Copyright © 2009 Commonwealth of Australia. Published by John Wiley & Sons, Ltd. [source]

Expression of tropane alkaloids in the hairy root culture of Atropa acuminata substantiated by DART mass spectrometric technique

BIOMEDICAL CHROMATOGRAPHY, Issue 8 2008
Suchitra Banerjee
Abstract Agrobacterium rhizogenes -mediated ,hairy root' cultures were established in Atropa acuminata. The chemical profiling of the hairy roots was carried out by a new mass spectrometric technique, direct analysis in real time (DART). The intact hairy roots were directly analyzed by holding them in the gap between the DART ion source and mass spectrometer. Two alkaloids, atropine and scopolamine, were characterized. The structural confirmation of the two alkaloids was made through their accurate molecular formula determinations. This is the first report of establishing hairy roots in A. acuminata as well as application of the DART technique for the chemical profiling of its hairy roots. Copyright © 2008 John Wiley & Sons, Ltd. [source]