The metabolic map of arecoline and arecaidine in the mouse. Identity of urinary metabolites is as follows: arecoline (I), arecaidine (II), arecoline N-oxide (III), arecaidine N-oxide (IV), N-methylnipecotic acid (V), N-methylnipecotylglycine (VI), arecaidinylglycine (VII), arecaidinylglycerol (VIII), arecaidine mercapturic acid (IX), arecoline mercapturic acid (X), and arecoline N-oxide mercapturic acid (XI).