Metabolism of alkenebenzene derivatives in the rat III. Elemicin and isoelemicin

Abstract

1. The metabolites of elemicin (3,4,5-trimethoxyallylbenzene) and isoelemicin (3,4,5-trimethoxypropenylbenzene) in the rat were identified by g.l.c.-mass spectrometry.

2. The major metabolic reactions of elemicin follow the cinnamoyl pathway or the epoxide-diol pathway. The former route gives 3-(3,4,5-trimethoxyphenyl)propionic acid and its glycine conjugate as major urinary metabolites, whereas 3-(3,4,5-trimethoxyphenyl)propane-1,2-diol is the most prominent metabolite of the latter route. Small amounts of the epoxide of the 3-O-demethylated derivative of elemicin were identified in the urine.

3. Isoelemicin was metabolized by both aforementioned pathways; the cinnamoyl pathway predominated and 3-(3,4,5-trimethoxyphenyl)propionic acid was the major urinary metabolite.

4. All of the acidic metabolites detected were C₆-C₃ derivatives and further oxidation to benzoic acid derivatives did not occur.

5. Most of the urinary metabolites were also found in the bile, but in different relative amounts.