(Science: chemical) An unstable intermediate between the prostaglandin endoperoxides and thromboxane b2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (rcs).
Chemical name: Thromboxa-5,13-dien-1-oic acid, 9,11-epoxy-15-hydroxy-, (5Z,9alpha,11alpha,13E,15S)-