scholarly journals Crystal structure of rofecoxib bound to human cyclooxygenase-2

2016 ◽  
Vol 72 (10) ◽  
pp. 772-776 ◽  
Author(s):  
Benjamin J. Orlando ◽  
Michael G. Malkowski
Keyword(s):  
Crystal Structure ◽  
Cardiovascular Effects ◽  
Cyclooxygenase 2 ◽  
The Public ◽  
Crystallization Conditions ◽  
Cox 2 ◽  
Isoform Selectivity ◽  
Cox 2 Inhibitors ◽  
Side Pocket

Rofecoxib (Vioxx) was one of the first selective cyclooxygenase-2 (COX-2) inhibitors (coxibs) to be approved for use in humans. Within five years after its release to the public, Vioxx was withdrawn from the market owing to the adverse cardiovascular effects of the drug. Despite the widespread knowledge of the development and withdrawal of Vioxx, relatively little is known at the molecular level about how the inhibitor binds to COX-2. Vioxx is unique in that the inhibitor contains a methyl sulfone moiety in place of the sulfonamide moiety found in other coxibs such as celecoxib and valdecoxib. Here, new crystallization conditions were identified that allowed the structural determination of human COX-2 in complex with Vioxx and the structure was subsequently determined to 2.7 Å resolution. The crystal structure provides the first atomic level details of the binding of Vioxx to COX-2. As anticipated, Vioxx binds with its methyl sulfone moiety located in the side pocket of the cyclooxygenase channel, providing support for the isoform selectivity of this drug.

Involvement of cyclooxygenase 2 (COX-2) in intrinsic tone of isolated guinea pig

1995 ◽  
Vol 73 (11) ◽  
pp. 1561-1567 ◽  
Author(s):  
L. Charette ◽  
C. Misquitta ◽  
J. Guay ◽  
D. Riendeau ◽  
T. R. Jones
Keyword(s):  
Guinea Pig ◽  
Time Course ◽  
Cyclooxygenase 2 ◽  
Maximal Response ◽  
Pharmacological Agents ◽  
Cyclooxygenase 1 ◽  
Inflammatory Drugs ◽  
Cox 2 ◽  
Cox 2 Inhibitors ◽  
Cox 1

Indomethacin and related nonsteroidal anti-inflammatory drugs relax prostanoid-dependent intrinsic tone of isolated guinea pig trachea by inhibiting cyclooxygenase (COX). Recently, a second isoform of COX (COX-2) was discovered, which differed from COX-1 with respect to protein structure, transcriptional regulation, and susceptibility to inhibition by pharmacological agents. It is now known that indomethacin nonselectively inhibits COX-1 and COX-2, whereas NS-398 is a selective inhibitor of COX-2. In the present study we compared the activity of a selective (NS-398) and nonselective (indomethacin) COX-2 inhibitor on intrinsic tone of isolated guinea pig trachea. NS-398 ≥ indomethacin produced a reversal of intrinsic tone with a similar concentration-dependent (10 nM to 1 μM) time course (Tmax approximately 20–45 min), potency (EC50 1.7 and 5.6 nM, respectively), and maximal response. Contractions to cholinergic nerve stimulation (45 V, 0.5 ms, 0.1–32 Hz) and histamine were similarly modulated in tissues relaxed with the selective or nonselective COX-2 inhibitors. Immunoblot analyses showed that COX-2 protein synthesis was induced in both the cartilage and smooth muscle portions of the trachea during changes in intrinsic tone. These findings are consistent with pharmacological results and provide the first demonstration that prostanoid tone in isolated guinea pig trachea is dependent on COX-2 activity. The results also suggest that the activity of indomethacin in this preparation is likely related to COX-2 inhibition.Key words: cyclooxygenase 2, relaxation, guinea pig trachea, cyclooxygenase 1.

scholarly journals STUDY ON THE SYNTHESIS OF PUERARIN DERIVATIVES AND THEIR ANTI-VASCULAR DEMENTIA ACTIVITY

2016 ◽  
Vol 8 (2) ◽  
pp. 11
Author(s):  
Pei Jiang
Keyword(s):  
Vascular Dementia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cyclooxygenase 2 ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
H Nmr ◽  
Cox 2 ◽  
Oxide Synthase

<p class="lead">In this study, puerarin derivatives were designed by adding an active acetonitrile group that inhibits cyclooxygenase-2 (COX-2) in order to enhance the anti-vascular dementia drug activity. The acetonitrile group was linked to puerarin at the 7/4 'positions by a phenolic hydroxyl to give 7-mono-and 7, 4' di-substituted derivatives of puerarin. These structures were confirmed by <sup>1</sup>H NMR spectroscopy and MS spectroscopy. We compared the affinity of puerarin derivatives and puerarin for cyclooxygenase-2 (COX-2) using molecular docking. In addition, the anti-vascular dementia activity of the developed puerarin derivatives was studied by water maze, novel object recognition, and the determination of inducible nitric oxide synthase (iNOS) enzyme activity at the cerebral cortex of mice. Experimental results showed that the puerarin derivatives have a good affinity for COX-2 with therapeutic effects against vascular dementia. The results of this study suggest that the protective effects of the puerarin derivatives against vascular dementia may be related to suppression of inflammation associated with ischemia-reperfusion injury through inhibition of COX-2.</p>

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