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  • 1
    Electronic Resource
    Electronic Resource
    Preparation of Dimethyl 7-Oxobicyclo[2.2.1]heptane-exo-2, exo-3 -  dicarboxylate. An Easy Route to Functionalized Norbornane Derivatives and Cage Compounds (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1715-1718 
    Details
    ISSN: 0009-2940
    Keywords: Bicyclo[2.2.1]heptanes ; Tricyclo[5.2.1.02,6]decanes ; Norbornanes ; Ozonization ; Cage compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A four-step preparation of dimethyl 7-oxobicyclo[2.2.1]-heptane-exo-2, exo-3-dicarboxylate (4) in satisfactory yield from the readily available 6,6-dimethylfulvene and maleic anhydride is described. Compound 4 represents a well-functionalized intermediate for the synthesis of norbornane derivatives which is used for an improved synthesis of the tricyclic diester 7, precursor of the cage compound 8. An alternative approach to diester 7 from dimethyl 7-isopropylidenebicyclo[2.2.1]heptane-exo-2, exo-3-dicarboxylate (2) is also discussed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230822
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  • 2
    Electronic Resource
    Electronic Resource
    Stereoselective metabolic pathways of ketoprofen in the rat: Incorporation into triacylglycerols and enantiomeric inversion (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 8 (1996), S. 163-172 
    Details
    ISSN: 0899-0042
    Keywords: arylpropionic acid ; ketoprofen ; enantiomer ; stereoselectivity ; Coenzyme A thioester ; hybrid triacylglycerols ; inversion ; adipose tissue ; hepatocytes ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The enantiomeric bioinversion of ketoprofen (KP) enantiomers and their incorporation into triacylglycerols were investigated in the rat (1) in vitro, using liver homogenates, subcellular fractions, and hepatocytes, and (2) in vivo, in different tissue samples after oral administration of the radiolabelled compounds. In liver homogenates or subcellular fractions, the enantiomer (S)-ketoprofen (S-KP) was recovered unchanged, whereas (R)-ketoprofen (R-KP) was partially converted into its Coenzyme A (CoA) thioester and inverted to S-KP. Both processes occurred mainly in the mitochondrial fraction. This supports the mechanism of inversion via stereoselective formation of CoA thioesters of R-KP, already described for other non-steroidal anti-inflammatory drugs. Incorporation into triacylglycerols was detected after incubation with intact hepatocytes in the presence of added glycerol. The process was stereoselective for R-KP vs. S-KP (covalently bound radioactivity 26,742 ± 4,665 dpm/106 cells vs. 6,644 ± 3,179 dpm/106 cells, respectively). However, no incorporation was found in liver samples after oral administration of either R-KP or S-KP. On the contrary, in adipose tissue samples a significant and stereoselective formation of hybrid triacylglycerols was observed: 11,076 ± 2,790 dpm.g-1 for R-KP vs. 660 ± 268 dpm.g-1 for S-KP. The incorporated R/S ratio, higher in adipose tissue (R/S = 17) than in hepatocytes (R/S = 4), indicates that fat may be the main tissue store for the xenobiotic R-KP in rats. © 1996 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Resolution of rac-ketoprofen esters by enzymatic reactions in organic media (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 5 (1993), S. 320-328 
    Details
    ISSN: 0899-0042
    Keywords: lipases ; amano M-AP-10 ; transesterification ; hydrolysis ; aminolysis ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enzyme-catalyzed reactions in organic media of rac-ketoprofen esters with different nucleophiles such as alcohols, amines, and water have been studied. Among the parameters optimized are the enzyme, the activated substrate, and the solvent. With the enzymes used in this study the preferred substrate was the trifluoroethyl ester of rac-ketoprofen (rac-2), whose (R)-enantiomer reacted preferentially. The enzyme of choice was the lipase M-AP-10 from Mucor miehei and best results were obtained with diisopropyl ether as solvent. Three different methods have been scaled-up for the resolution of 75-150 g of substrate: transesterification with 1-butanol (90% yield of (S)-ketoprofen, 88% ee), transesterification with 2-(2-pyridyl)ethanol (94% yield, 92% ee), and hydrolysis in wet organic solvent (93% yield, 97% ee). Despite the comparable chemical and optical yields obtained with these three methods, the use of 2-(2-pyridyl)ethanol and the hydrolysis allowed a much easier work-up and isolation of the desired (+)-(S)-ketoprofen. © 1993 Wiley-Liss, Inc.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chir.530050508
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  • 4
    Electronic Resource
    Electronic Resource
    Stereoselective inhibition of rat brain cyclooxygenase by dexketoprofen (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 9 (1997), S. 281-285 
    Details
    ISSN: 0899-0042
    Keywords: dexketoprofen ; enantiomer ; stereoselectivity ; brain ; cyclooxygenase ; rat ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Although it has been assumed that the effects of nonsteroidal antiinflammatory drugs (NSAIDs) are mainly the result of their action on local synthesis of prostaglandins, there is growing evidence to suggest that they may also exert a central analgesic action. Some authors have suggested that inhibition of prostaglandin synthesis in the brain could contribute to the analgesic action. The effect of dexketoprofen trometamol (tromethamine salt of the enantiomer (+)-S-ketoprofen) on prostaglandin synthesis was investigated in rat brain fragments and in cyclooxygenase preparations from rat brain microsomes. Effects of the (-)-R-enantiomer and the racemic mixture were also evaluated. Significant levels of prostaglandin F2α (PGF2α) were synthesized in rat brain fragments after 10 min of incubation at 37°C. Dexketoprofen was found to be a potent inhibitor of this PGF2α production in rat brain (IC50 = 6.2 nM), and it completely suppressed PGF2α production at 1 μM concentration. In addition, inhibition of PGF2α synthesis by dexketoprofen was highly stereoselective since the enantiomer (-)-R-ketoprofen was significantly less potent (IC50 = 294 nM); with this enantiomer, even at high concentrations such as 1 μM, less than 60% inhibition was achieved. These results correlated with those obtained in the study of racemic ketoprofen and its enantiomers on cyclooxygenase activity of rat brain microsomes, where dexketoprofen also inhibited enzymatic activity stereoselectively. IC50 values obtained for dexketoprofen, (-)-R-ketoprofen, and rac-ketoprofen were 3.5 μM, 45.3 μM, and 5.8 μM, respectively. The above results could be related to the potent analgesic effect of dexketoprofen observed in vivo, which was also stereoselective. Taken together, these findings suggest that prostaglandin synthesis inhibition in rat brain by dexketoprofen could be associated, at least in part, with the analgesic effect of this NSAID. Chirality 9:281-285, 1997. © 1997 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Stereoselective cyclooxygenase inhibition in cellular models by the enantiomers of ketoprofen (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 5 (1993), S. 589-595 
    Details
    ISSN: 0899-0042
    Keywords: NSAIDs ; enantioselectivity ; prostaglandin E2 ; thromboxane B2 ; HUVEC ; PMN ; keratinocytes ; P388D1 ; platelets ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pharmacological activity of rac-ketoprofen and its enantiomers was investigated in vitro using different cellular models. The effect of these compounds on arachidonic acid metabolism was assessed by measuring the inhibition of prostanoid generation under the action of several agonists. Thus, we have evaluated the inhibition of (1) thromboxane B2 synthesis in rabbit platelets and human polymorphonuclear leukocytes (PMNs), (2) prostaglandin E2 synthesis in three cultured cells, namely human umbilical vein endothelial cells (HUVEC), human keratinocytes, and mouse macrophage-like P388D1 cells. The IC50 values found for (+)-(S)-ketoprofen were in the range between 0.1 nM and 0.8 μM, being slightly lower in all models than those found for rac-ketoprofen (0.4 nM-3 μM). On the other hand, (-)-(R)-ketoprofen showed inhibition of cyclooxygenase only at concentrations two or three orders of magnitude higher than those required for the (+)-(S) enantiomer. These results, obtained with cell types of relevance for inflammatory processes and with compounds of high optical purity, demonstrate that the prostanoid biosynthesis inhibition caused by the drug rac-ketoprofen is exclusively due to its dextrorotatory enantiomer. © 1993 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chir.530050805
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  • 6
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of ketoprofen enantiomers in monkeys following single and multiple oral administration (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 6 (1994), S. 537-542 
    Details
    ISSN: 0899-0042
    Keywords: arylpropionic acid ; ketoprofen ; chiral inversion ; stereoselective pharmacokinetics ; monkey ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pharmacokinetic studies are reported after single oral administration of 3 mg/kg of stereochemically pure (S)-ketoprofen [(S)-KP] and (R)-ketoprofen [(R)-KP] to three male Cynomolgus monkeys and after repeated administration for 6 months of 3, 15 and 75 mg/kg/day of (S)-KP to both male and female monkeys. A high-performance liquid chromatographic (HPLC) analysis was performed without derivatization of the samples, using a chiral column. The pharmacokinetic parameters for (S)-KP after administration of (S)-KP and for (R)-KP after administration of (R)-KP were, respectively, elimination half-life 2.32 ± 0.36 and 1.64 ± 0.40 h; oral clearance 3.50 ± 0.66 and 7.50 ± 3.20 ml/min/kg; apparent volume of distribution 0.74 ± 0.24 and 1.16 ± 0.76 liter/kg; mean residence time 1.79 ± 0.77 and 1.41 ± 0.65 h; area under the concentration/time curve 14.16 ± 2.93 and 7.31 ± 2.98 μg·h/ml. Forty-nine percent unidirectional bioinversion of (R)-KP to (S)-KP was observed in this species and the pharmacokinetic parameters for the (S)-KP resulting from this inversion were also calculated. In the study of 6-month repeated administration of (S)-KP, linear pharmacokinetic behavior and no evidence of drug accumulation were observed at the three dose levels. © 1994 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chir.530060705
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  • 7
    Electronic Resource
    Electronic Resource
    Easy and General Method for the Preparation of m- and p-Acylbenzoic Acids: A New Synthesis of rac-Suprofen (1993)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 641-643 
    Details
    ISSN: 0170-2041
    Keywords: Acylbenzoic acids ; Claisen condensation ; rac-Suprofen ; Thallium(III) nitrate ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method for the preparation of m- and p-acylbenzoic acids 3 based on the Claisen condensation of isophthalic or terephthalic diesters 1 with α-methylenecarboxylic esters 2 is described. p-Propionylbenzoic acid p-4 (R = Me) is used in a new synthesis of rac-suprofen (11).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1993199301104
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