Diketopiperazines as a new class of platelet-activating factor inhibitors.

Synthese et etude biologique de S-methyl methyl-1' cyclocysteinyltryptophyles, de methyl-1' cyclomethionyltryptophiles et de methylthio-2' ethyl-3 [naphtyl-1]-1' ethyl-6 piperazinediones-2,5