Structure-activity relationships in platelet-activating factor (PAF antagonists). 6. Synthesis and in vitro antagonistic activities of 2-substituted 5-oxotetrahydrofurans.

: The synthesis of 2,5-disubstituted tetrahedrofuran compounds as potential in vitro PAF antagonists is described. Results demonstrate that the structural requirements for potent PAF antagonist activity are: a moderate lipophilic group or a trimethoxyphenyl group in position-5, and a long aliphatic chain terminated by a cationic polar head in position-2. The cis-trans configuration does not induce any difference in biological activity. Some conformational features of the putative PAF receptor are proposed in light of the present findings.