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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 1 (1987), S. 403-412 
    ISSN: 0268-2605
    Keywords: Trimethyl-2-hydroxyethylarsonium salts ; arsenocholine ; trimethyl-2-haloethylarsonium bromide ; trimethyl-2-acetoxyethylarsonium bromide ; acetylarsenocholine ; trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide ; 1H and 13C NMR spectra ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Trimethyl-2-X-ethylarsonium salts (X=OH, Cl, Br, CH3COO; anion=Br) and trimethyl-2-diethoxyethylarsonium bromide were prepared from trimethylarsine and the appropriate organic bromides in sealed tubes at elevated temperatures or by refluxing the neat reagents. The yields ranged from 33 to 85%. Anion exchange reactions produced the arsonium iodides, nitrates, acetates, tosylates, tetraphenylborates, picrates, hydroxides, and carbonates. Arsenocholine bromide (X=OH) was phosphorylated with concentrated phosphoric acid. The product was isolated as the barium salt. Treatment of the barium salt with sulfuric acid yielded trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide. These substances were synthesized to serve as precursors for arsenic- containing phospholipids and as standards for the chromatographic identification of arsenocholines. The synthesized compounds were characterized by elemental analyses and 1H and 13C NMR spectroscopy. The shifts of the arsenic compounds were compared with those of the corresponding nitrogen compounds and found to be sufficiently different to be used for the identification of these compounds in their mixtures.
    Additional Material: 1 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 4 (1990), S. 103-109 
    ISSN: 0268-2605
    Keywords: Arsenic-containing lipids ; 2-trimethylarsonioethylphosphonic acid bromide ; 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethylphosphonate ; arsenic-containing phosphonolipid ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Arsenic analogs of lecithins (i.e. with replacement of nitrogen by arsenic in the choline group) are probably trace constituents of phospholipids in many organisms. Attempts to synthesize 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethyl phosphate (arsenolecithin) according to wellestablished procedures for the synthesis of the corresponding nitrogen compound failed. However, 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethylphosphonate, an arsenic-containing phosphonolipid, was obtained in 16% yield by reacting 1,2-bis(palmitoyloxy)-3-iodopropane with silver 2-trimethylarsonioethylphosphonate in isopropanol. The precursors to the arsenic-containing phosphonolipid were obtained by quaternization of trimethylarsine with diethyl 2-bromoethylphosphonate, hydrolysis of the resulting product with concentrated hydrochloric acid, and reaction of the phosphonic acid with silver oxide to give silver 2-trimethylarsonioethylphosphonate. Quaternization and hydrolysis proceeded almost quantitatively. The silver phosphonate was not isolated but was used in situ.
    Additional Material: 2 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 191-202 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction of catenapoly(diphenoxy-λ5-phosphazene) (1) with SO3 in 1,2-dichloroethane at 15°C, applying a mole ratio m = [SO3]/[--P(OC6H5)2N - ] ≤ 1,0 and subsequent quenching with water, leads to catenapoly(diphenoxy-λ5-phosphazene-co-diphenoxy-λ5-phosphazenium hydrogen sulfate) (2) containing up to 57% protonated nitrogen. At m 〉 1,0 C-sulfonation occurs, resulting in the formation of water-soluble catenapoly[diphenoxy-λ5-phosphazene-co-diphenoxy-λ5-phosphazenium hydrogen sulfate-co-bis(sulfophenoxy)-λ5-phosphazenium hydrogen sulfate] (3). The latter can be converted into catenapoly[diphenoxy-λ5-phosphazene-co-bis(sulfophenoxy)-λ5-phosphazene] (4b) by treatment with alkali and subsequent percolating through a cation exchange resin. Analytical results show that C-sulfonation is preceded by the formation of a polymer-SO3 donor-acceptor complex.
    Additional Material: 1 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 504-507 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectrum of cinnoline has been measured at high field (250 MHz) and analysed as an H-8-de-coupled ABCXY and H-4-decoupled ABCX system. Inter-ring H—H couplings have been determined and discussed in relation to theoretical values obtained using INDO calculations.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 8 (1976), S. 457-460 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C n.m.r. spectra are reported for 1,3-indandione, phthalic anhydride, thiophthalic anhydride, and phthalimide in chloroform-d solution. The 13C chemical shifts have also been calculated by means of Pople's perturbation theory using CNDO/S wave functions; the agreement between theoretical and experimental values is improved when an empirical charge-dependent term is added to the calculated diamagnetic and paramagneitc contributions.
    Additional Material: 1 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 9 (1977), S. 401-403 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C n.m.r. spectra are reported for 1,2-indandione, coumarandione and thionaphthenequinone in CDCl3 solution and for isatin in dimethyl sulphoxide solution. The chemical shifts are assigned and discussed in connection with the influence of the heteroatom on the dicarbonyl group and the aromatic ring. The 13C shieldings have also been calculated by means of Pople's perturbation theory using CNDO/S wave functions.
    Additional Material: 2 Tab.
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  • 7
    ISSN: 1434-193X
    Keywords: Cyclodextrins ; Inclusion compounds ; Carcinine ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A new modified β-cyclodextrin (β-CD) derivative 1 that was functionalized in position 6 with Boc-Carcinine was synthesised and its crystal structure was determined. The structure reveals a “sleeping swan”-like shape, the covalently bonded Boc-Carcinine moiety forming a folded structure with the Boc group inserted within the hydrophobic cavity of the β-cyclodextrin. The conformation of the Carcinine moiety is determined by the inclusion of the Boc group and is further stabilised by three intramolecular hydrogen bonds, two between the amide N1-H group, the carbonyl C′1=O1 group and a primary hydroxylic group of the glucose unit 5, one between the carbonyl C′0=O0 group and the primary hydroxylic group of the glucose unit 2. The β-CD macrocycle differs only slightly from unmodified β-CDs, maintaining an approximate sevenfold symmetry. The solution structure of the new β-CD derivative was investigated by NMR spectroscopy and circular dichroism (c.d.) spectroscopy. In addition to a complete (1H and 13C) assignment of the pendant Boc-Carcinine group, the NMR study allowed the assignment of all the proton resonances associated with the β-CD macrocycle. Furthermore, NMR and c.d. results indicated that the self-inclusion of the Boc group within the β-CD cavity is retained in aqueous solution. In order to estimate the strength of this self-inclusion complex a series of competition experiments with the external guest 1-adamantanol was carried out using c.d. spectroscopy.
    Additional Material: 9 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 26 (1988), S. 693-700 
    ISSN: 0749-1581
    Keywords: 1H NMR ; 13C NMR ; Benzomorphans ; 2D NMR ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The high-frequency 1 and 13C NMR spectra (at 500 and 75.47 MHz, respectively) of metazocine (MTZ) fumarate, pentazocine (PTZ) and cyclazocine (CLZ) hydrochlorides in 2H2O solution were recorded and analysed with the aid of both homonuclear 1H—1H and heteronuclear 13C—1H chemical shift correlation experiments. At neutral pH all compounds were found to be configurationally heterogeneous, with the N-equatorial isomer more populated than the N-axial isomer (ratio ca 80:20). The low-intensity peaks of the superimposed spectral pattern of the less populated isomer were also assigned on correlative grounds in both the 1H and 13C NMR spectra of MTZ, PTZ and CLZ. The occurrence of distinct spectra for the two configurational isomers was diagnostic of a ‘slow’ exchange process on the NMR time-scale at the field frequencies employed for the experiments, thus suggesting a high-energy barrier to interconversion. The experimental proton-proton coupling constants measured for the N-equatorial form of MTZ, PTZ and CLZ were consistent with a chair conformation of the piperdinic ring in all compounds. The distinct relative agonist-antagonist potencies of the drugs investigated could therefore not be correlated with the above-described configurational and conformational features.
    Additional Material: 6 Ill.
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  • 9
    ISSN: 0749-1581
    Keywords: Arsenolipid ; 2D NMR ; 1H and 13C NMR ; 31P arsenophosphonolipid ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1H (500 MHz), 13C (300 MHz) and 31P (202 MHz) NMR spectra of rac-2,3-bis(palmitoyloxy)propyl(2-trimethylarsonioethyl)phosphonate were recorded in CDCl3 (3 M) solution. Homonuclear 1H-1H and heteronuclear 13C-1H chemical shift correlation experiments (COSY) were performed. All resonances were assigned. The shifts of the arsenic-containing phosphonolipid were compared with the shifts of the N-containing phospholipids. The most significant shift differences were found for the groups directly bonded to arsenic. Spectral evidence was indicative of free rotation about the —CH2 —CH2 —bond in the arsenocholine fragment.
    Additional Material: 5 Ill.
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  • 10
    ISSN: 0749-1581
    Keywords: Cognition activator drugs ; Inclusion complexes ; Cyclodextrins ; NMR-ROESY ; Molecular modelling ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structural features of the inclusion complexes of cyclodextrins (CDs) with the chiral cognition activator drug (±)9-[(phenylmethyl)amino]-1,2,3,4-tetrahydroacridin-1-ol maleate (suronacrine maleate, HP-128) were studied using both high-resolution 1H NMR spectroscopy and molecular modelling methods. The partial inclusion of the guest from the secondary hydroxyl side of α-CD was demonstrated in aqueous solution, in addition to a higher degree of penetration into the cavity of β-CD from the same side. NMR-ROESY experiments allowed the unambiguous location of the benzylic ring of the guest inside the β-CD cavity. The formation of diastereoisomeric pairs was demonstrated by the duplication of the benzylic proton signals. Molecular mechanics calculations were used to complement the NMR analysis. Molecular modelling procedures (MacroModel interactive computer program) allowed the prediction of the most stable structures of the complexes, and showed that specific site interactions, provided by hydrogen bond formation, are capable of differentiating the diastereoisomeric intramolecular inclusion complexes according to available experimental NMR data.
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