Studies on the Biotransformation of Paeonol by Means of Isotope Tracer Techniques

—Synthesis and Physicochemical Properties of Carbon-13 and Deuterium Labeled Compounds—

Abstract

In order to perform the metabolic study of paeonol (I) in human and animals by using isotope tracer techniques, synthesis of I and its urinary metabolites labeled with carbon-13 or deuterium was investigated.
2-Hydroxy-4-methoxy [d₃] acetophenone, 2, 5-dihydroxy-4-methoxy [d₃] acetophenone, and re-sacetophenone [acetyl-¹³C₂] were synthesized from methyl iodide-d₃, dimethyl sulfate-d₆, and acetic acid-1, 2-¹³C₂, respectively.
Physicochemical studies by IR and NMR spectra showed that stable isotope was not elimi-nated during the synthetic process of each compound. For the quantification of the metabolites by GC-MS analysis, isotope effect on gas chromatography and fragmentation was studied.