sentence: We demonstrated that the RTA activity was not due to allicin , but instead the 2-propenesulfenic acid formed via Cope elimination from allicin ( eqn ( 1 ) and ( 2 ) ) .33 The same mechanism was demonstrated for petivericin ( 2 ) , the analogous thiosulfinate derived from Petiveria alliacea – also known as the medicinal plant anamu found in South and Central America .