The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Neil W. Barnett - One of the best experts on this subject based on the ideXlab platform.
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Rapid determination of Papaver somniferum alkaloids in process streams using monolithic column high-performance liquid chromatography with chemiluminescence detection
Analytica chimica acta, 2007Co-Authors: Jason W. Costin, Simon W. Lewis, Stuart D. Purcell, Lucy Waddell, Paul S. Francis, Neil W. BarnettAbstract:We have combined high-performance liquid chromatography (HPLC) separations using a monolithic column with acidic potassium permanganate and tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence detection in a rapid and highly sensitive method to monitor the process of extracting opiate alkaloids from Papaver somniferum. Due to the high flow rates allowed with the monolithic column and the inherent selectivity of the chemiluminescence reactions, the four predominant alkaloids – morphine, codeine, Oripavine and thebaine – were determined in less than 2 min. The results obtained with numerous process samples compared favourable with those of the standard HPLC methodology. Limits of detection were 1 × 10−10 M, 5 × 10−10 M, 5 × 10−10 M and 1 × 10−9 M, for morphine, codeine, Oripavine and thebaine, respectively.
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A hybrid FIA/HPLC system incorporating monolithic column chromatography
Analytica Chimica Acta, 2007Co-Authors: Jacqui L. Adcock, Paul S. Francis, Kent M. Agg, Graham D. Marshall, Neil W. BarnettAbstract:We have combined the generation of solvent gradients using milliGAT pumps, chromatographic separations with monolithic columns and chemiluminescence detection in an instrument manifold that approaches the automation and separation efficiency of HPLC, whilst maintaining the positive attributes of flow injection analysis (FIA), such as manifold versatility, speed of analysis and portability. As preliminary demonstrations of this hybrid FIA/HPLC system, we have determined six opiate alkaloids (morphine, pseudomorphine, codeine, Oripavine, ethylmorphine and thebaine) and four biogenic amines (vanilmandelic acid, serotonin, 5-hydroxyindole-3-acetic acid and homovanillic acid) in human urine, using tris(2,2'-bipyridyl)ruthenium(III) and acidic potassium permanganate chemiluminescence detection.
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Determination of opiate alkaloids in process liquors using capillary electrophoresis
Journal of pharmaceutical and biomedical analysis, 2006Co-Authors: Benjamin J. Hindson, Paul S. Francis, Stuart D. Purcell, Neil W. BarnettAbstract:This paper describes the determination of opiate alkaloids (morphine, codeine, Oripavine and thebaine) in industrial process liquors using capillary zone electrophoresis with UV-absorption detection at 214 nm. A study of cyclodextrin type and concentration revealed that the addition of 30 mM hydroxypropyl-beta-cyclodextrin to the electrolyte solution (100mM Tris adjusted to pH 2.8) was suitable to resolve the four analytes of interest. Typical analysis time was 12 min and the limit of detection for each alkaloid was 2.5 x 10(-6) M. The results for the proposed methodology were in good agreement with those of a conventional HPLC procedure. Under the same conditions, short-end injection was used to reduce the effective separation length from 41.5 to 8.5 cm, which allowed the determination of morphine and thebaine in process liquors within 2.5 min.
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Preliminary Evaluation of Dual Acidic Potassium Permanganate and Tris(2,2-bipyridyl)ruthenium(ii) Chemiluminescence Detection for the HPLC Determination of Papaver somniferum Alkaloids
Australian Journal of Chemistry, 2004Co-Authors: Claire E. Lenehan, Neil W. Barnett, Simon W. Lewis, Kevin M. EsseryAbstract:This paper describes a dual chemiluminescence reagent for the determination of the opiate alkaloids morphine, codeine, Oripavine, and thebaine in Papaver somniferum extracts. Detection was achieved using a mixture of acidic potassium permanganate and tris(2,2′-bipyridyl)ruthenium(ii), where the former acted as both the oxidant for the latter and as a chemiluminescence reagent in its own right. The analytes were separated on a C 8 column using ion-pairing HPLC. The application of the mixed reagent detection compared favourably with results obtained using standard HPLC methodology. Detection limits for the alkaloids were 10 -6 , 5 × 10 -7 , 3 × 10 -6 , and 2 × 10 -6 mol L -1 for morphine, codeine, Oripavine, and thebaine, respectively.
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Determination of morphine, Oripavine and pseudomorphine using capillary electrophoresis with acidic potassium permanganate chemiluminescence detection
The Analyst, 2000Co-Authors: Neil W. Barnett, Benjamin J. Hindson, Simon W. LewisAbstract:A simple and robust capillary electrophoresis chemiluminescence detection system for the determination of morphine, Oripavine and pseudomorphine is described, based upon the reaction of these analytes with acidic potassium permanganate in the presence of sodium polyphosphate. The reagent solution was contained in a quartz detection cell which also held both the capillary and the anode. The resultant chemiluminescence was monitored directly using a photomultiplier tube mounted flush against the base of the detection cell. To ensure that no migration of the permanganate anion occurred, the anode was placed at the detector end whilst the electroosmotic flow was reversed by the addition of hexadimethrine bromide (0.001% m/v) to the electrolyte. The three analytes were separated counter to the electroosmotic flow via their interaction with α-cyclodextrin. The methodology realised detection limits (3 × S/N) of 2.5 × 10−7 M for both morphine and Oripavine and 5 × 10−7 M for pseudomorphine. The relative standard deviations of the migration times and the peak heights for the three analytes ranged from 0.6 up to 0.8% and from 1.5 up to 2.1%, respectively.
Adam Mccluskey - One of the best experts on this subject based on the ideXlab platform.
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Corrigendum to “Isolation and identification of unique marker compounds from the Tasmanian poppy Papaver somniferum N. Implications for the identification of illicit heroin of Tasmanian origin” [Forensic Sci. Int. 175 (2008) 202–208]
Forensic Science International, 2009Co-Authors: Luke R. Odell, Jana Skopec, Adam MccluskeyAbstract:The corresponding author wishes to inform readers of FSI, that as a result of discussions with the Tasmanian Poppy Advisory and Control Board (PACB), and subsequent investigations that the analysis described in the above article does not accurately reflect the current state of the Tasmanian poppy industry. Accordingly, the corresponding author urges extreme caution in the use and citation of this work. Notwithstanding the above, the isolation and characterization of products from the treatment of Oripavine with acetic anhydride are correct.
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Isolation and identification of unique marker compounds from the Tasmanian poppy Papaver somniferum N. Implications for the identification of illicit heroin of Tasmanian origin.
Forensic Science International, 2007Co-Authors: Luke R. Odell, Jana Skopec, Adam MccluskeyAbstract:Tasmanian opium accounts for 25% of the world's legal supply of opium straw, and in 1998-99 sufficient numbers of flower pods (66,013) to manufacture ca 500 kg of heroin were stolen. Whilst the heroin signature program has been developed to determine the origin of heroin from other key producers, no such signature currently exists for Tasmanian derived heroin. Tasmanian poppies contain a unique alkaloid, Oripavine, which is the source of 'marker' impurities in illicit heroin produced from Tasmanian poppy straw. Treatment of Oripavine (500mg) under Thiboumery and Mohr heroin processing conditions, followed by simple evaporative workup afforded 613 mg of a dark orange residue, which upon extensive chromatographic purification yielded Oripavine 3-acetate (2) 22 mg; 3-acetyl-N-acetyldesthebaine (3) 35 mg; 3-acetyl-6-methoxy-4,5-epoxyphenanthrene (4) 5.8 mg; 3,4-diacetyl-6-methoxyphenanthrene (5) 27 mg; and 3,4,6-methoxy-5-[2(N-methylacetamido)]ethylphenanthrene (6) 52 mg. Compounds (2-6) are derived from Oripavine and are unique to heroin derived from the Tasmanian poppy Papaver somniferum N. Analysis of illicit heroin samples seized from Turkey, Pakistan, Columbia and Myanmar did not reveal any of the aforementioned marker compounds. We have, however, identified four of these marker compounds (3-6) in seized heroin samples from Australia suggesting that they are of Tasmanian origin. Complete details of the isolation and identification of these compounds are provided.
Luke R. Odell - One of the best experts on this subject based on the ideXlab platform.
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Corrigendum to “Isolation and identification of unique marker compounds from the Tasmanian poppy Papaver somniferum N. Implications for the identification of illicit heroin of Tasmanian origin” [Forensic Sci. Int. 175 (2008) 202–208]
Forensic Science International, 2009Co-Authors: Luke R. Odell, Jana Skopec, Adam MccluskeyAbstract:The corresponding author wishes to inform readers of FSI, that as a result of discussions with the Tasmanian Poppy Advisory and Control Board (PACB), and subsequent investigations that the analysis described in the above article does not accurately reflect the current state of the Tasmanian poppy industry. Accordingly, the corresponding author urges extreme caution in the use and citation of this work. Notwithstanding the above, the isolation and characterization of products from the treatment of Oripavine with acetic anhydride are correct.
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Isolation and identification of unique marker compounds from the Tasmanian poppy Papaver somniferum N. Implications for the identification of illicit heroin of Tasmanian origin.
Forensic Science International, 2007Co-Authors: Luke R. Odell, Jana Skopec, Adam MccluskeyAbstract:Tasmanian opium accounts for 25% of the world's legal supply of opium straw, and in 1998-99 sufficient numbers of flower pods (66,013) to manufacture ca 500 kg of heroin were stolen. Whilst the heroin signature program has been developed to determine the origin of heroin from other key producers, no such signature currently exists for Tasmanian derived heroin. Tasmanian poppies contain a unique alkaloid, Oripavine, which is the source of 'marker' impurities in illicit heroin produced from Tasmanian poppy straw. Treatment of Oripavine (500mg) under Thiboumery and Mohr heroin processing conditions, followed by simple evaporative workup afforded 613 mg of a dark orange residue, which upon extensive chromatographic purification yielded Oripavine 3-acetate (2) 22 mg; 3-acetyl-N-acetyldesthebaine (3) 35 mg; 3-acetyl-6-methoxy-4,5-epoxyphenanthrene (4) 5.8 mg; 3,4-diacetyl-6-methoxyphenanthrene (5) 27 mg; and 3,4,6-methoxy-5-[2(N-methylacetamido)]ethylphenanthrene (6) 52 mg. Compounds (2-6) are derived from Oripavine and are unique to heroin derived from the Tasmanian poppy Papaver somniferum N. Analysis of illicit heroin samples seized from Turkey, Pakistan, Columbia and Myanmar did not reveal any of the aforementioned marker compounds. We have, however, identified four of these marker compounds (3-6) in seized heroin samples from Australia suggesting that they are of Tasmanian origin. Complete details of the isolation and identification of these compounds are provided.
A. M. Villar - One of the best experts on this subject based on the ideXlab platform.
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A new HPLC method for the analysis of alkaloids in poppy straw
Fitoterapia, 1995Co-Authors: M.p. Gómez-serranillos, E. Carretero, A. M. VillarAbstract:A reversed-phase high-performace liquid chromatographic procedure was developed for the qualitative and quantitative analysis of the main alkaloids (morphine, codeine and thebaine), together with Oripavine, in poppy straw. The column consoted of radial compression cartdridges packed with C 18 as the stationary phase. The mobile phase was a gradient of acetonitrile and an aqueous solution of octanesulfonic acid sodium salt
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Analysis of poppy straw and poppy straw concentrate by reversed‐phase high‐performance liquid chromatography
Phytochemical Analysis, 1994Co-Authors: Pilar Gómez-serranillos, E. Carretero, A. M. VillarAbstract:A method of reversed-phase high-performance liquid chromatography using an elution gradient has been developed to analyse morphine, codeine, thebaine, and Oripavine — this last-mentioned substance for the first time — in samples of poppy straw and poppy straw concentrate. Gradient elution of the octadecylsilane column was performed: the gradient was from 10 to 30% of solvent A (methanol) in solvent B (containing 67% of 0.5% aqueous ammonium acetate solution containing diethylamine, and 33% of methanol) over a 25 min period. The four alkaloids were identified and quantified with the aid of an internal standard.
Tomas Hudlicky - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Naltrexone and (R)-Methylnaltrexone from Oripavine via Direct Oxidation of Its Quaternary Salts
Synlett, 2015Co-Authors: Ales Machara, Lukas Werner, Hannes Leisch, Robert J. Carroll, David R. Adams, D. Mohammad Haque, D. Phillip Cox, Tomas HudlickyAbstract:(R)-Methylnaltrexone and naltrexone were each prepared in four steps from Oripavine in practical yields. The procedure involved quaternization of Oripavine with cyclopropylmethyl halides, singlet oxygen oxidation of the quaternary salts, and the reduction of endo peroxides to 14-hydroxyketone functionalities. (R)-Methylnaltrexone was prepared from the corresponding R-diastereomer of the Oripavine salt. All diastereomeric mixtures of the quaternary salts were subjected to N-demethylation with sodium thiolate to yield cyclopropyl methylnorOripavine, which was converted into naltrexone by peracid oxidation and hydrogenation according to established procedures.
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AWARD LECTURE Recent advances in process development for opiate-derived pharmaceutical agents
2015Co-Authors: Tomas HudlickyAbstract:This short review summarizes our work on the process development for the synthesis of buprenorphine, naltrexone, naloxone, and nalbuphine from naturally occurring opiates such as thebaine and Oripavine. Several new methods for N-demethylation of morphinans have been developed during the pursuit of this research. The article traces the evolution of various approaches and provides a comparison for overall efficiency.
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Recent advances in process development for opiate-derived pharmaceutical agents
Canadian Journal of Chemistry, 2015Co-Authors: Tomas HudlickyAbstract:This short review summarizes our work on the process development for the synthesis of buprenorphine, naltrexone, naloxone, and nalbuphine from naturally occurring opiates such as thebaine and Oripavine. Several new methods for N-demethylation of morphinans have been developed during the pursuit of this research. The article traces the evolution of various approaches and provides a comparison for overall efficiency.
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Synthesis of Nalbuphine from Oripavine via N-Demethylation of N-Cyclobutylmethyl Oripavine.
ChemInform, 2012Co-Authors: Ales Machara, D. Phillip Cox, Tomas HudlickyAbstract:The synthesis of nalbuphine (VI) from Oripavine (I) requires only five chemical transformations and is conducted with an overall yield of 45%, in contrast to current methods requiring seven to ten steps.
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Improved Synthesis of Buprenorphine from Thebaine and/or Oripavine via Palladium‐Catalyzed N‐Demethylation/Acylation and/or Concomitant O‐Demethylation
Advanced Synthesis & Catalysis, 2012Co-Authors: Ales Machara, Lukas Werner, D. Phillip Cox, Mary Ann A. Endoma-arias, Tomas HudlickyAbstract:An improved preparation of buprenorphine via palladium-catalyzed N-demethylation/acylation is reported. Three routes were investigated and compared in overall yield. The first involved N-demethylation/acylation of an advanced intermediate obtained from thebaine followed by hydrolysis of the N-acetamide and alkylation with cyclopropylmethyl bromide and/or reduction of the N-acetyl group with the Schwartz reagent followed by N-alkylation. The second route employed cyclopropylcarboxylic acid anhydride in the N-demethylation/acylation protocol and subsequent reduction of the cyclopropylcarboxamide by either lithium aluminum hydride or under hydrosilylation conditions. Both of these routes originated in thebaine and therefore required O-demethylation as a final step. The third route employed an N-demethylation/acylation sequence starting from Oripavine rather than thebaine, thus avoiding the O-demethylation. The routes are compared for overall efficiency and experimental and spectral data are provided for all new compounds.