title: Comparative antiaggregatory activity in human platelets of a benzopyranone aci-reductone, clofibric acid, and a 2,3-dihydrobenzofuran analogue.
abstract: A synthetic method for the preparation of aci-reductone 6-chloro-3,4-dihydroxy-2H-1-benzopyran-2-one (3) from 5-chlorosalicylate is presented. In human platelets, the benzopyranone derivative 3, clofibric acid (1), and the 2,3-dihydrobenzofuran analogue 4 inhibited aggregation and serotonin secretory responses to adenosine diphosphate (ADP) with a rank order of potency 3 greater than or equal to 4 greater than 1. Only analogues 3 and 4 consistently blocked the aggregatory responses (greater than 50%) to arachidonic acid (AA) and U46619, a thromboxane A2 agonist. Further, the rank order of inhibitory potency against U46619-induced serotonin secretion was 4 greater than 3 greater than 1. Benzopyranone 3 is of interest since it was the most potent inhibitor of thrombin-induced [3H]AA release (3 much greater than 4 = 1) and more potent than 1 or 4 for the blockade of the ADP- or AA-mediated pathway of platelet aggregation.
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism / Q000494:pharmacology; D001572:Benzofurans / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism; D002994:Clofibrate / Q000031:analogs & derivatives*; D002995:Clofibric Acid / Q000494:pharmacology*; D003374:Coumarins / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D010974:Platelet Aggregation / Q000187:drug effects*; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D001095:Arachidonic Acids; D001572:Benzofurans; D003374:Coumarins; D011450:Prostaglandin Endoperoxides, Synthetic; C050650:6-chloro-3,4-dihydroxy-2H-1-benzopyran-2-one; D016718:Arachidonic Acid; D012701:Serotonin; D002995:Clofibric Acid; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C023614:dibenzofuran; D002994:Clofibrate