Illustrated Glossary of Organic Chemistry

COX (cyclooxygenase): A group of enzymes which convert arachidonic acid plus oxygen into prostaglandin H2 (PGH2), a step in prostaglandin biosynthesis. Some anti-inflammatory pharmaceuticals work by inhibiting COX enzymes. There are two COX forms: COX-1 which is widely distributed in the body, and COX-2 which is usually specific to inflamed tissue.

COX enzymes are involved in prostaglandin biosynthesis. Because prostaglandins mediate the inflammatory response, numerous pharmaceuticals (such as aspirin) that inhibit COX have been developed.