Identification of tertiary aminomethylenedioxy-propiophenones as urinary metabolites of safrole in the rat and guinea pig

Three nitrogen-containing metabolites of safrole (1-allyl-3,4-methylenedioxy-benzene) are excreted in the urine of rats and/or guinea pigs following oral or intraperitoneal administration. The major safrole basic ninhydrin-positive metabolites of the guinea pig and rat are 3-N-N-dimethylamino-1-(3′,4′-methylenedioxyphenyl)-1-propanone and 3-piperidyl-1-(3′,4′-methylenedioxyphenyl)-1-propanone, respectively. In addition, the rat also excretes the above N,N-dimethylaminoketone and trace amounts of 3-pyrrolidinyl-1-(3′,4′-methylenedioxyphenyl)-1-propanone. All three of these aminoketones decompose to form 1-(3′,4−methylenedioxyphenyl)-3-propen-1-one.