Analysis Of Natural Products Research Articles

Profiling Taxanes in Taxus Extracts Using Lc/ms and Lc/ms/ms Techniques

Analytical methodology developed for the trace analysis of natural products in crude extracts was utilized for the rapid and systematic structure elucidation of taxanes in Taxus extracts and process intermediates. This method integrates analytical hplc, uv detection, uv spectroscopy, full-scan ionspray mass spectrometry and tandem mass spectrometry on-line. The identification of structure of a taxane is based on comparing the mass spectrometric characteristics of the taxane with the paclitaxel substructural "template." Analytical data for taxanes in preparations from Taxus brevifolia and Taxus baccata were observed, including chromatographic characteristics using a standard hplc system, molecular weight, and collision induced dissociation (cid) tandem mass spectrometry (ms/ms) product ion spectra. The data obtained for 18 taxanes from natural sources using this method provided a taxane profile database useful for the rapid identification of taxanes in mixtures and samples of limited quantity.

Capillary gas chromatography‐spectroscopic techniques in natural product analysis

AbstractThe current state of the art in capillary gas chromatography (CGC), CGC‐mass spectroscopy (CGC‐MS), CGC‐Fourier transform infrared spectroscopy (CGC‐FTIR) and CGC‐atomic emission detection (CGC‐AED) is discussed with emphasis on their routine applicability in natural product analysis as experienced in the laboratories of the authors.

Liquid chromatography-mass spectrometry with ionspray and electrospray interfaces in pharmaceutical and biomedical research

Electrospray and ionspray techniques use samples that exist as ions or ion-molecule complexes in solution. After the dispersion of the solution into an electrically charged aerosol, the sample ions may escape from the solution into the gas phase in a region that is at atmospheric pressure. The sample ions are transported into the mass analyser which is operated under a high vacuum. Liquid chromatographs can be coupled to electrospray and ionspray interfaces. Flow injection or continuous infusion of a sample solution (both without the use of a separating column) may be preferred over on-line liquid chromatography-mass spectrometry in certain applications. Electrospray or ionspray is applicable to polar or ionic samples. Weakly polar and apolar samples are not ionized under electrospray or ionspray conditions. Applications of the techniques are in the fields of drug metabolism, natural product analysis and the determination of high molecular weights through the observation of multiply charged ions.

Optimization of the analytical supercritical fluid extraction of cloves via an on-column interface to an ion trap GC/MS system

The analytical supercritical fluid extraction of cloves via a direct on-column interface to high-resolution GC and an ion trap mass spectrometer was undertaken to evaluate the optimum potential of this system for analysis of complex natural products.

New planar chromatographic techniques in natural product analysis

Planar chromatography (PLC) is gaining importance in the analysis of natural products. Sophisticated instrumentation has become available in this field. Major progress in planar chromatography has been achieved through the development of forced-flow techniques. Progress has also been made in the capillary-controlled flow techniques with the use of modified development chambers. A large variety of stationary phases is available and strategies to optimize mobile phase compositions in PLC have been developed. The detection and quantitation in PLC has improved through direct coupling of PLC with spectroscopic methods with and the use of modern, computerized scanning densitometers.

A facile degradation procedure for determination of absolute configuration in 1,3-dimethyltetra- and dihydroisoquinolines

The ruthenium-mediated oxidative degradation of chiral 1,3-dimethyl substituted di- and tetrahydroisoquinolines is described. Preparative isolation of the resulting 3-aminobutyric acid, or its analysis by GC after Moshertype derivatization, gives direct information on the configuration at C-3 of the tetrahydroisoquinoline. For trans-configurated tetrahydroisoquinolines, the stereocentre at C-1 may also be elucidated in the same analytical step, by analysis of the amino acid alanine formed. The applicability of the method to the analysis of natural products is demonstrated for naphthylisoquinoline alkaloids.

ChemInform Abstract: NMR Techniques for the Structure Elucidation and Conformational Analysis of Natural Products

ChemInform Abstract: NMR Techniques for the Structure Elucidation and Conformational Analysis of Natural Products

ChemInform Abstract: Identification and Analysis of a Degradation Product of the Glucocorticoid Desonide in Ointment.

ChemInformVolume 19, Issue 51 Natural Products ChemInform Abstract: Identification and Analysis of a Degradation Product of the Glucocorticoid Desonide in Ointment. T. T. NGUYEN, T. T. NGUYEN Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this authorR. KRINGSTAD, R. KRINGSTAD Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this authorA. J. AASEN, A. J. AASEN Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this authorK. E. RASMUSSEN, K. E. RASMUSSEN Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this author T. T. NGUYEN, T. T. NGUYEN Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this authorR. KRINGSTAD, R. KRINGSTAD Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this authorA. J. AASEN, A. J. AASEN Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this authorK. E. RASMUSSEN, K. E. RASMUSSEN Dep. Chem., Agric. Univ. Norway, N-1432 As-NLH, NorwaySearch for more papers by this author First published: December 20, 1988 https://doi.org/10.1002/chin.198851303Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue51December 20, 1988 RelatedInformation

Analysis of natural products by tandem mass spectrometry employing reactive collisions with ethyl vinyl ether

AbstractRepresentative natural products from the diterpene dilactone, psorospermin and quabalactone classes were protonated, mass‐selected and reacted with ethyl vinyl ether in a triple‐quadrupole mass spectrometer. Minor differences in the structures of the compounds led to different reactivities toward the reagent, as indicated by the relative abundances of products such as the ethylated and vinylated compounds. Additional information is obtained from the dissociation products formed upon non‐reactive, inelastic collisions with the neutral reagent. The daughter spectra have excellent signal: noise ratios and good reproducibility. The results demonstrate that the use of reactive collisions may supplement collision‐activated dissociation in chemical analysis of large organic molecules by tandem mass spectrometry.

Application of Countercurrent Chromatography/Thermospray Mass Spectrometry for the Analysis of Natural Products

Abstract The versatility and high resolving power of countercurrent chromatography (CCC) has been demonstrated with a newly developed analytical high speed planet centrifuge system. Interfacing countercurrent chromatography with mass spectrometry (MS) provides a new analytical methodology which integrates the advantages of countercurrent chromatography with the low detection limit and identification capability of mass spectrometry. The capability of thermospray CCC/MS is evidenced in a preliminary study of plant alkaloids. The technique proved useful in identifying an unknown impurity and in validating the presence of a specific compound in a mixture. The thermospray CCC/MS can become a useful and complementary method to thermospray HPLC/MS for the analysis of nonvolatile or thermally unstable molecules.

ChemInform Abstract: Bismuth(V) Reagents in Organic Synthesis

The concept that the valency change from BiV to Bi could be harnessed to produce a family of selective oxidants as shown to be correct. However, completely unexpected was the efficiency of Bi reagents in carrying out arylations on oxygen, carbon and nitrogen. The new arylation procedures permit the synthesis under very mild conditions of compounds only available otherwise by indirect routes. In general, these arylation reactions do not involve radical intermediate, but are rather examples of reductive elimination. The Chemistry of Natural Products has always been associated with major advances in Organic Chemistry from its origin up to the present time. Major objectives of Natural Product Chemistry have been first the determination of structure, and then synthesis. Due to the development of powerful physical methods, the structural analysis of natural products is now a relatively trivial matter. The synthesis of natural products however has remained an active field, always requiring new synthetic methods. As we argued some years ago, the invention of new synthetic methods takes place through conception, or misconception, or by accident (ref. 1). We will examine some of our work which resulted from the combination of the first and third concept, i.e. application of a conceptually devised reaction to the Chemistry of Natural Products which led to an accident and the development of a family of unusual arylation reactions. Mild and selective oxidation of polyfunctional substrates remains a major goal for organic chemists. Metal and metalloid oxides have been used for a long time. However, reactions can be more or less selective, and recycling of the oxidant, thus giving a catalytic system, is rarely seen. The reactivity of metalloids like selenium, tellurium or bismuth is improved through using covalently bonded substituted derivatives. Thus the chemistry of compounds (ref. 2) has grown into an active field. Some such examples can be found in the chemistry of selenium (ref. 3), tellurium (ref. 4), iodine (ref. 5) to name only a few. Among borderline organo—metalloid derivatives, in the group VA, organobismuth derivative?4ha15 ben3known for a long time (ref. 6). With an electronic configuration [Xe] 4p 5d 6s 6p , bismuth has all its lower—energy orbitals filled, leaving five electrons in non—equivalent outer arbitals. The participation of the two s electrons leads to two possible valencies : Bi(III) and Bi(V). As expected, two series of organic compounds exist : the trivalent derivatives with a pair of non—bonded s electrons, and the pentavalent derivatives. The Bi(V) —> Bi(III) change led to the conception of an oxidation reaction (Scheme 1), which might moreover be developed into a catalytic reaction, as in the group VI elements. Scheme 1. Conception of the Oxidation Mechanism ,.H Ph3 =0

Chemical analysis and comparison of subspecies of Chrysothamnus nauseosus and other related species

Rubber rabbitbrush ( Chrysothamnus nauseosus) is a large species complex of plants that are well adapted to a wide range of semi-arid habitats. A high resin and rubber content gives some subspecies possible commercial value. Analysis of natural products produced by these plants in relation to each other provides valuable information on taxonomic and chemical relationships. A cyclohexane extraction of C nauseousus subsp, rnohavensis, hololeucus, albicaulis, viridulus, turbinatus, graveolens, C. teretifolius, C. linifolius and C. viscidiflorus subsp, viscidiflorus, lanceolatus were analyzed by gas chromatography- mass spectrometry. The 10 most abundant peaks were compared from each sample resulting in a pool of 60 compounds which were identified using an NBS-Wiley Library of about 78 000 mass spectral compounds. Cluster analysis of the data showed that all of the C. nauseosus subsp, grouped together indicating similar chemical composition. Chrysothamnus teretifolius grouped closer to the C. nauseousus subsp, than to the others. Chrysotharnnus linifolius grouped closer to each of the C. viscidiflorus subsp, than they did to each other. Some plants contained unique compounds, and others were restricted to related taxa.

Bismuth(V) reagents in organic synthesis

Abstract

ChemInform Abstract: The Analysis of Natural Products

Chemischer InformationsdienstVolume 17, Issue 25 Reviews ChemInform Abstract: The Analysis of Natural Products A. R. PINDER, A. R. PINDERSearch for more papers by this author A. R. PINDER, A. R. PINDERSearch for more papers by this author First published: June 24, 1986 https://doi.org/10.1002/chin.198625353Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume17, Issue25June 24, 1986 RelatedInformation

Complete proton and carbon-13 NMR assignment of the alkaloid gephyrotoxin through the use of homonuclear Hartmann-Hahn and two-dimensional spectroscopy

Three different types of modem NMR techniques have been used to obtain a complete proton and carbon- 13 assignment of the alkaloid gephyrotoxin. In addition to the two-dimensional phase-sensitive homo- and heteronuclear shift correlation methods, use of the recently proposed one-dimensional homonuclear Hartmann-Hahn difference experiment was crucial for obtaining the required long-range connectivity. Guidelines are presented for optimal use of these techniques. Experiments were performed at 500-MHz 'H frequency, using 8 mg of sample. The introduction of two-dimensional (2D) NMR techniques has greatly simplified the NMR analysis of many natural products, permitting the study of problems hitherto considered intractable. As an example, we present here a study of the alkaloid gephy- rotoxin (GyTx), extracted from the skin of the frog Dendrobates histrionicus. Routine application of standard 2D NMR techniques is not sufficient in this case because of the complexity of the 'H

Le pharmacien Jacques Personne (1816-1880), pionnier de la chimie analytique

The Pharmacist Jacques Personne (1816-1880), a Pioneer in Analytical Chemistry ; Born in Saulieu (Cote-d'Or), a city in Burgundy, Jacques Personne began an apprenticeship in pharmacy in 1833. Orphaned in 1837 when his father, a lime-burner, died in an accident, Personne underwent great hardship and moved to a pharmacy in Paris. After competitive examinations in 1839, he became a hospital intern and began working under Antoine Bussy, Director of the School of Pharmacy in Paris. Another competitive examination qualified him as chief hospital pharmacist, a post he held in three successive Paris hospitals until his death. His connection with the School of Pharmacy in Paris was continuous from 1843 to 1880, first as « preparateur », then « chef de travaux » and finally as lecturer in analytical chemistry. Personne carried on almost four decades of unremitting research, mainly on triglycerides in the blood and lead in florus auriantiae hydrolatum. He discovered iodine in a small moss growing in fresh water near Saulieu. He carried out a complete work of chloral, isolating new crystalline hemiacetals. Personne established many volumetric methods of analysis and studied the chemical analysis of various natural products. He was admitted to the Academy of Medicine in 1875.

Applications of HPLC for the Analysis of Natural Products

In a comparison of adsorption to reversed phase chromatography examples optimal separation of digitalis glycosides will be given. Possibilities for both gradient elution and construction of low - cost gradients and their application to extracts of senna glycosides will be discussed. Various aspects of sample application and procedures for compound concentration will be shown in connection with trace analysis.

Use of Acid-Dye Technique in the Analysis of Natural Products. III. Spectrophotometric Microdetermination of Khellin and Bergapten

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of Acid-Dye Technique in the Analysis of Natural Products. III. Spectrophotometric Microdetermination of Khellin and BergaptenS. M. Ibrahim, H. A. Kadry, and M. M. El-OlemyCite this: J. Nat. Prod. 1979, 42, 4, 366–373Publication Date (Print):July 1, 1979Publication History Published online1 July 2004Published inissue 1 July 1979https://doi.org/10.1021/np50004a003RIGHTS & PERMISSIONSArticle Views110Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (404 KB) Get e-Alerts Get e-Alerts

The use of glass capillary columns for the analysis of polar natural products

AbstractTwo published procedures for glass capillary column production are applied to produce capillaries for chromatography of polar natural compounds. Soda lime glass capillaries, after leaching with aqueous HCL, are either treated with colloidal silicic acid or with barium carbonate and coated with either Silar 7CP or SE 52. A test mixture as well as polar carbohydrate and peptide mixtures are chromatographed on the different columns and their chromatographic properties are evaluated. Combined capillary gas chromatography‐electron impact and chemical ionization mass spectrometry are used for identification of the peptide sequence.

Application of gas liquid chromatography-mass spectrometry to analysis of natural products. Waxes from Mangifera indica and Sesbania grandiflora

Application of gas liquid chromatography-mass spectrometry to analysis of natural products. Waxes from Mangifera indica and Sesbania grandiflora