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41.
The metabolism of (+/-)fenfluramine, 1-(m-trifluoromethylphenyl)-2-N-ethylpropane, an anoretic agent, was investigated in humans. The analysis method was based on the use of ion-exchange resin extraction, solid-phase purification on the Bond Elut1M C8 cartridge, gradient elution high-performance liquid chromatography, enzymic hydrolysis of conjugates, further purification by Bond Elut C8 cartridge, derivatisation and capillary column gas chromatography-mass spectrometry (GC-MS). After administration of a 1 mg kg-1 oral dose, four metabolites plus unchanged fenfluramine were recovered in the 0-24 h urine from human volunteers and characterised by GC-MS. In the conjugated form, fenfluramine, norfenfluramine and m-trifluoromethylhippuric acid were detected by GC-MS. In the aglycone form, the major metabolite, 1-(m-trifluoromethylphenyl)-1,2-propane diol (fenfluramine diol), was monitored using GC-MS. The mass spectral characteristics of the m-trifluoromethylhippuric acid methyl ester, 1-(m-trifluoromethylphenyl)-1,2-propane ditrifluoracetate derivatives and the norfenfluramine and fenfluramine free base obtained under electron-impact ionization are presented. The metabolism of fenfluramine is discussed including a metabolic pathway in man accounting for the formation of its biotransformation products. 相似文献
42.
We report a novel source of tunable, coherent radiation in the vacuum ultraviolet, which use resonantly enhanced difference-frequency mixing in xenon gas Efficiencies are high (o.4%) at modest input laser intensities. With existing dye lasers the range of tunability will span the 152–200 nm region. 相似文献
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Fluorinated Musk Fragrances: The CF2 Group as a Conformational Bias Influencing the Odour of Civetone and (R)‐Muscone 下载免费PDF全文
Dr. Ricardo Callejo Dr. Michael J. Corr Mingyan Yang Prof. Mingan Wang Dr. David B. Cordes Prof. Alexandra M. Z. Slawin Prof. David O'Hagan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(24):8137-8151
The difluoromethylene (CF2) group has a strong tendency to adopt corner over edge locations in aliphatic macrocycles. In this study, the CF2 group has been introduced into musk relevant macrocyclic ketones. Nine civetone and five muscone analogues have been prepared by synthesis for structure and odour comparisons. X‐ray studies indeed show that the CF2 groups influence ring structure and they give some insight into the preferred ring conformations, triggering a musk odour as determined in a professional perfumery environment. The historical conformational model of Bersuker and co‐workers for musk fragrance generally holds, and structures that become distorted from this consensus, by the particular placement of the CF2 groups, lose their musk fragrance and become less pleasant. 相似文献
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Liam J. R. McGeachie Cameron L. Carpenter-Warren David B. Cordes Michael Bühl Steven J. Gray Guoxiong Hua Alexandra M. Z. Slawin J. Derek Woollins 《无机化学与普通化学杂志》2020,646(22):1795-1798
An improved route to d-block and main group NSO complexes is presented including the synthesis of the first antimony(V) complexes, (Ar3Sb(NSO)2), and copper examples [CuBipy(PPh3)NSO]. The structures of eight complexes are reported. The observed variation in M–N–S bond angles is due to the combination of orbital overlap (ligand-to-metal bonding) and the degree of ionicity of the bonding. 相似文献
47.
Rajeev Rajasekharan‐Nair Dean Moore Dr. Kirsten Chalmers Dr. Dawn Wallace Louise M. Diamond Lisa Darby Dr. David R. Armstrong Dr. John Reglinski Dr. Mark D. Spicer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2487-2495
The alkylation reactions of soft scorpionates are reported. The hydrotris(S‐alkyl‐methimazolyl)borate dications (alkyl=methyl, allyl, benzyl), which were prepared by the reaction of TmMe anion and primary alkyl halides, have been isolated and structurally characterised. The reaction is, however, not universally successful. DFT analysis of these alkylation reactions (C?S versus B? H alkylation) indicates that the observed outcome is driven by kinetic factors. Extending the study to incorporate alternative imine thiones (mercaptobenzothiazole, bz; thiazoline, tz) led to the structural characterisation of di[aquo‐μ‐aquohydrotris(mercaptobenzothiazolyl)boratosodium], which contains sodium atoms in the κ3‐S,S,S coordination mode. Alkylation of Na[Tbz] and Na[tzTtz] leads to decomposition resulting in the formation of the simple S‐alkylated heterocycles. The analysis of the species involved in these reactions shows an inherent weakness in the B? N bond in soft scorpionates, which has implications for their use in more advanced chemistry. 相似文献
48.
Guoxiong Hua Cameron L. Carpenter-Warren David B. Cordes Alexandra M. Z. Slawin J. Derek Woollins 《Molecules (Basel, Switzerland)》2021,26(8)
A series of N-aryl-N-(2-oxo-2-arylethyl) benzamides and cinnamides has been prepared. The reaction of the benzamides with Woollins’ reagent, a highly efficient chemoselective selenation/reduction reagent, gave the corresponding N-aryl-N-(arylenethyl) benzoselenoamides in good yields. Five representative single crystal X-ray structures are discussed. 相似文献
49.
Warburton RE McCarthy A Wallace AM Hernandez-Marin S Hadfield RH Nam SW Buller GS 《Optics letters》2007,32(15):2266-2268
We demonstrate subcentimeter depth profiling at a stand off distance of 330 m using a time-of-flight approach based on time-correlated single-photon counting. For the first time to our knowledge, the photon-counting time-of-flight technique was demonstrated at a wavelength of 1550 nm using a superconducting nanowire single-photon detector. The performance achieved suggests that a system using superconducting detectors has the potential for low-light-level and eye-safe operation. The system's instrumental response was 70 ps full width at half-maximum, which meant that 1 cm surface-to-surface resolution could be achieved by locating the centroids of each return signal. A depth resolution of 4 mm was achieved by employing an optimized signal-processing algorithm based on a reversible jump Markov chain Monte Carlo method. 相似文献
50.
Matthew Wallace Andre Zamith Cardoso Dr. William J. Frith Dr. Jonathan A. Iggo Dr. Dave J. Adams 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16484-16487
The magnetic‐field‐induced alignment of the fibrillar structures present in an aqueous solution of a dipeptide gelator, and the subsequent retention of this alignment upon transformation to a hydrogel upon the addition of CaCl2 or upon a reduction in solution pH is reported. Utilising the switchable nature of the magnetic field coupled with the slow diffusion of CaCl2, it is possible to precisely control the extent of anisotropy across a hydrogel, something that is generally very difficult to do using alternative methods. The approach is readily extended to other compounds that form viscous solutions at high pH. It is expected that this work will greatly expand the utility of such low‐molecular‐weight gelators (LMWG) in areas where alignment is key. 相似文献