(rel)-MK 287

(rel)-MK 287 rel)-L-680573) is a relative configuration of MK 287. MK 287, a tetrahydrofuran analog, potently inhibited [3H]C18-PAF binding to human platelet, polymorphonuclear leukocyte (PMN) and lung membranes with Kis of 6.1 nM, 3.2 nM and 5.49 nM, respectively. MK 287 inhibits PAF-induced lethality in mice and PAF-induced bronchoconstriction in guinea pigs.