in rats , a single administration of acrylonitrile ( vinyl cyanide ) produces a rapidly occurring bilateral adrenal apoplexy . 
 structure - activity studies have shown that a close derivative , propionitrile ( ethyl cyanide ) , causes duodenal ulcer without markedly affecting the adrenal glands . 
 prolonging the two - carbon chain of propionitrile by a methyl group ( n - butyronitrile ) enhances , replacing the methyl by bromide or nitrile decreases , while substitution by an amino group abolistes the ulcerogenic potency and variably affects the adrenocorticolytic action . on assaying a large number of nonnitrile compounds as well for ulcerogenic effect , such as thiols and amines , 
 this effect was found to be related to a two - carbon structure bearing electronegative radicals on one or both ends of the chain.imagesfigure 1 . 
 afigure 1 . 
 bfigure 1 . 
 afigure 1 . 
 bfigure 2.figure 3 . 
 afigure 3 . 
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