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  • Analytical Chemistry and Spectroscopy  (6)
  • prostaglandins  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Regulatory role of eicosanoids in extracellular matrix overproduction induced by long-term exposure to high glucose in cultured rat mesangial cells (1996)
    Springer
    Diabetologia 39 (1996), S. 1055-1062 
    Details
    ISSN: 1432-0428
    Keywords: Keywords Extracellular matrix ; transforming growth factor-β ; prostaglandins ; thromboxane ; mesangial cell ; diabetes mellitus.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Accumulation of extracellular matrix in the mesangium and altered renal eicosanoid synthesis are two prominent features of diabetic glomerular disease. We investigated the relationship between eicosanoid and extracellular matrix production in rat mesangial cells cultured under high glucose vs normal glucose conditions. Long-term exposure of rat mesangial cells to high glucose, but not to iso-osmolar mannitol, significantly increased extracellular matrix accumulation and gene expression and transforming growth factor-β (TGF-β) mRNA levels, and decreased prostaglandin (PG) E2 synthesis without affecting production of either thromboxane (TX) B2 or PGF2 a, with respect to cells incubated in normal glucose. Addition of exogenous PGE2 resulted in a dose-dependent reduction of matrix protein and mRNA levels and TGF-β gene expression in cells cultured in either normal or high glucose conditions, whereas exposure to exogenous PGF2α produced a significant increment in matrix production and matrix and TGF-β gene expression in cells grown in normal glucose, but only a slight increase in those cultured in high glucose. Stimulation of endogenous endoperoxide metabolism towards PGE2 and PGF2α synthesis with FCE-22,178, a drug originally developed as TXA2 synthase inhibitor, resulted in a dose-dependent decrease in matrix accumulation and matrix and TGF-β gene expression which was suppressed by co-incubation with the cyclo-oxygenase inhibitor fenoprofen blocking the FCE-22,178-enhanced PG production. In both cell lines, the rate of synthesis of TXA2 was very low and the selective blockade of its synthesis (by two other TXA2 synthase inhibitors, OKY-046 and Ridogrel) or action (by the TXA2 receptor antagonist BM-13,177) did not alter matrix production or TGF-β mRNA levels. These results suggest that the cyclo-oxygenase pathway is involved in the regulation of matrix changes induced by high glucose in rat mesangial cells; the reduced production of PGE2 may enhance the synthesis or potentiate the effect of stimulators of ECM formation such as TGF-β, whereas TXA2 does not appear to be involved. These data also indicate that glucose-enhanced mesangial matrix accumulation may be prevented by exogenous PGE2 or by drugs capable of increasing endogenous PGE2 synthesis. [Diabetologia (1996) 39: 1055–1062]
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400654
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  • 2
    Electronic Resource
    Electronic Resource
    Regulatory role of eicosanoids in extracellular matrix overproduction induced by long-term exposure to high glucose in cultured rat mesangial cells (1996)
    Springer
    Diabetologia 39 (1996), S. 1055-1062 
    Details
    ISSN: 1432-0428
    Keywords: Extracellular matrix ; transforming growth factor-Β ; prostaglandins ; thromboxane ; mesangial cell ; diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Accumulation of extracellular matrix in the mesangium and altered renal eicosanoid synthesis are two prominent features of diabetic glomerular disease. We investigated the relationship between eicosanoid and extracellular matrix production in rat mesangial cells cultured under high glucose vs normal glucose conditions. Long-term exposure of rat mesangial cells to high glucose, but not to iso-osmolar mannitol, significantly increased extracellular matrix accumulation and gene expression and transforming growth factor-Β (TGF-Β) mRNA levels, and decreased prostaglandin (PG) E2 synthesis without affecting production of either thromboxane (TX) B2 or PGF2α, with respect to cells incubated in normal glucose. Addition of exogenous PGE2 resulted in a dose-dependent reduction of matrix protein and mRNA levels and TGF-Β gene expression in cells cultured in either normal or high glucose conditions, whereas exposure to exogenous PGF2α produced a significant increment in matrix production and matrix and TGF-Β gene expression in cells grown in normal glucose, but only a slight increase in those cultured in high glucose. Stimulation of endogenous endoperoxide metabolism towards PGE2 and PGF2α synthesis with FCE-22,178, a drug originally developed as TXA2 synthase inhibitor, resulted in a dose-dependent decrease in matrix accumulation and matrix and TGF-Β gene expression which was suppressed by co-incubation with the cyclo-oxygenase inhibitor feno-profen blocking the FCE-22,178-enhanced PG production. In both cell lines, the rate of synthesis of TXA2 was very low and the selective blockade of its synthesis (by two other TXA2 synthase inhibitors, OKY-046 and Ridogrel) or action (by the TXA2 receptor antagonist BM-13,177) did not alter matrix production or TGF-Β mRNA levels. These results suggest that the cyclo-oxygenase pathway is involved in the regulation of matrix changes induced by high glucose in rat mesangial cells; the reduced production of PGE2 may enhance the synthesis or potentiate the effect of stimulators of ECM formation such as TGF-Β, whereas TXA2 does not appear to be involved. These data also indicate that glucose-enhanced mesangial matrix accumulation may be prevented by exogenous PGE2 or by drugs capable of increasing endogenous PGE2 synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400654
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Constituents of Satureia calamintha. Application of Eu(fod)3 to the assignments of the methyl resonances of triterpenes related to 12-urseneThis work was presented in part at the ‘Convegno 1975 di Chimica organica, Sezione Siciliana della S.C.I.’. (1977)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 9 (1977), S. 29-34 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The n.m.r. spectra of triterpenoids related to 12-ursene have been examined using the shift reagent Eu(fod)3. The assignment of all the methyl resonances has been achieved for ursolic acid derivatives and the corresponding compounds of the 3-epi series, which have not been investigated previously. The additive shielding effects of various substituents on the methyl resonance frequencies have been deduced from the results.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270090107
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  • 4
    Electronic Resource
    Electronic Resource
    Nuclear magnetic resonance of 1,4-benzodiazepines. IIFor Part I see Ref. 1. Stereochemistry of 1,3-dihydro-2H-1,4-benzodiazepin-2-ones by lanthanide shift reagentsThis work was presented in part at the XIIIème Congrés de la Société de Pharmacie de la Méditerranée Latine, Toulouse, 11-14 mai, 1978. (1979)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 12 (1979), S. 593-597 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The sterochemistry of some 1,3-dihydro-2H-1,4-benxodiazepin-2-ones, employed as psychotherapeutic agents, is deduced by proton magnetic resonance using the paramagnetic shift reagent Eu(fod)3. the lanthanide induced shifts are computer simulated on the basis of the geometric parameters of the protons in different model structures, having intermediate conformations between a cycloheptadiene- and a cyclohepatatriene-like system. N-Desmethyldiazepam shows a conformational equilibrium between two pseudoboat forms, while the 1-alkyl substituted derivatives exist, at room temperature, in olny one boat cycloheptatriene-like conformation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270121010
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  • 5
    Electronic Resource
    Electronic Resource
    Nuclear magnetic resonance of psychotherapeutic agents. IVFor part III see Ref. 1. - conformational analysis of 2,3-dihydro-1H-1,4-benzodiazepines (1981)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 15 (1981), S. 33-36 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The lanthanide shift reagent (LSR)/1H NMR study of some 7-chloro-5-phenyl-2,3-dihydro-1 H-1, 4-benzodiazepines shows that these compounds exist in CDCI3 solution as two pseudo-boat conformers, rapidly interconverting at room temperature. Computer simulated lanthanide induced shifts (LIS) are consistent with LSR complexation by the imine nitrogen atom. The lanthanide shifts the conformational equilibrium towards conformer (a), with a pseudoequatorial 1-substituent: this effect may be the result of the greater basicity of 4-N when the 1-N lone pair is pseudoaxially directed, thus permitting an extended electron delocalization from 1- to 4-N through the fused benzene ring. The detection of H-9/1-Me through space spin-spin coupling in medazepam (7-chloro-1-methyl-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepine) supports the observed higher availability of conformer (a) to LSR. A LIS computer calculation to predict the population ratio results in reasonable agreement with the conformational changes based on the response of 3J(HH) to lanthanide addition. The electronic and steric effects which determine the greater stability of conformer (a) may be effective in the drug-receptor interaction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270150109
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  • 6
    Electronic Resource
    Electronic Resource
    Nuclear magnetic resonance spectra of psychotherapeutic agents. V* - conformational analysis of 1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-onesFor Part IV, see Ref. 5. (1981)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 15 (1981), S. 394-398 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conformational analysis of biologically active lofendazam (7-chloro-5-phenyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one) is carried out by means of lanthanide shift reagent assisted 1H NMR spectroscopy: the lanthanide induced shift computer simulation suggests that in deuteriochloroform the heterocyclic ring of lofendazam assumes a cycloheptene-like chair conformation, where 1-N moves away from trigonal stereochemistry to a very flattened pyramidal structure. At room temperature the conformational equilibrium is markedly shifted (85%) towards the conformer showing pseudoaxial H-1 and 5-Ph. The remarkable influence of steric requirements in controlling conformation, and the importance of 3- and/or 4-methyl groups in hindering the ring inversion at room temperature, have been verified by conformational analysis of suitable analogous 1,3,4,5-tetraydro-2H-1,5-benzodiazepin-2-ones.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270150414
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  • 7
    Electronic Resource
    Electronic Resource
    13C NMR study of tetrahydrothiazolo-[3,2-d][1,4]benzodiazepin-3[2H]-ones (1989)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 27 (1989), S. 702-705 
    Details
    ISSN: 0749-1581
    Keywords: 13C NMR ; Tetra-hydrothiazolo [3,2-d] [1,4] benzodiazepin -3(2H)-ones ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The complete assignments of the 13C NMR resonances for eight tetra-hydrothiazolo [3,2-d] [1,4] benzodiazepin -3(2H)-ones are reported. The data obtained account for a conformational rigidity of the heptatomic ring as a consequence of the annelation of the thiazolidinone nucleus.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260270720
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  • 8
    Electronic Resource
    Electronic Resource
    Determination of the stereochemistry of isoxazolidinium salts by nuclear Overhauser effect difference spectroscopy (1988)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 26 (1988), S. 974-979 
    Details
    ISSN: 0749-1581
    Keywords: 1H NMR ; NOEDS measurements ; Isoxazolidinium salts ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The configurations of some isoxazolidinium salts have been determined by nuclear Overhauser effect difference spectroscopy (NOEDS). The stereochemical findings give a good explanation of the different reactivities experienced in the five-membered ring-opening process as a function of the steric requirement of the system.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260261108
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