has role is deprotonated form of piperidine An azacycloalkane that is cyclohexane in which one of the carbons is replaced by a nitrogen. It is a metabolite of cadaverine, a polyamine found in the human intestine. base piperidines secondary amine reagent catalyst saturated organic heteromonocyclic parent azacycloalkane non-polar solvent protic solvent piperidinium plant metabolite human metabolite