Biochemically based design of cyclooxygenase-2 (COX-2) inhibitors: facile conversion of nonsteroidal antiinflammatory drugs to potent and highly selective COX-2 inhibitors.
All nonsteroidal antiinflammatory drugs (NSAIDs) inhibit the cyclooxygenase (COX) isozymes to different extents, which accounts for their anti-inflammatory and analgesic activities and their gastrointestinal side effects. We have exploited biochemical differences between the two COX enzymes to identify a strategy for converting carboxylate-containing NSAIDs into selective COX-2 inhibitors. Derivatization of the carboxylate moiety in moderately selective COX-1 inhibitors, such as 5,8,11,14-eicosatetraynoic acid (ETYA) and arylacetic and fenamic acid NSAIDs, exemplified by indomethacin and meclofenamic acid, respectively, generated potent and selective COX-2 inhibitors. In the indomethacin series, esters and primary and secondary amides are superior to tertiary amides as selective inhibitors. Only the amide derivatives of ETYA and meclofenamic acid inhibit COX-2; the esters are either inactive or nonselective. Inhibition kinetics reveal that indomethacin amides behave as slow, tight-binding inhibitors of COX-2 and that selectivity is a function of the time-dependent step. Site-directed mutagenesis of murine COX-2 indicates that the molecular basis for selectivity differs from the parent NSAIDs and from diarylheterocycles. Selectivity arises from novel interactions at the opening and at the apex of the substrate-binding site. Lead compounds in the present study are potent inhibitors of COX-2 activity in cultured inflammatory cells. Furthermore, indomethacin amides are orally active, nonulcerogenic, anti-inflammatory agents in an in vivo model of acute inflammation. Expansion of this approach can be envisioned for the modification of all carboxylic acid-containing NSAIDs into selective COX-2 inhibitors.
Kalgutkar
A S
AS
A. B. Hancock, Jr., Memorial Laboratory for Cancer Research, Department of Biochemistry, Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.
Crews
B C
BC
Rowlinson
S W
SW
Marnett
A B
AB
Kozak
K R
KR
Remmel
R P
RP
Marnett
L J
LJ
D015117:5,8,11,14-Eicosatetraynoic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000577:Amides; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015195:Drug Design; D004487:Edema / Q000517:prevention & control; D004952:Esters; D005767:Gastrointestinal Diseases / Q000139:chemically induced; D006614:Hindlimb; D006801:Humans; D007213:Indomethacin / Q000009:adverse effects / Q000031:analogs & derivatives / Q000494:pharmacology; D007527:Isoenzymes / Q000494:pharmacology*; D007700:Kinetics; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008469:Meclofenamic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D008565:Membrane Proteins; D051379:Mice; D011451:Prostaglandin-Endoperoxide Synthases / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012756:Sheep
D000577:Amides; D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D004952:Esters; D007527:Isoenzymes; D008565:Membrane Proteins; D015117:5,8,11,14-Eicosatetraynoic Acid; D008469:Meclofenamic Acid; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D007213:Indomethacin