Disposition of 4,6,4'-trimethylangelicin in mice maintained in the dark and after UVA irradiation.

The disposition of the furocoumarin 4,6,4'-trimethylangelicin (4,6,4'-TMA) was studied in mice. After oral administration of (3)H 4,6,4'-TMA, radioactivity measured in serum shows fast absorption and slow elimination. Serum protein binding is higher as compared to 8-methoxypsoralen (8-MOP), currently used in photochemotherapy (PUVA) and linearly declines from 30 min to 6 h after administration. Distribution in the various organs was similar to that of 8-MOP and was relatively uninfluenced by UVA radiation, required for the biological effects of 4,6,4'-TMA. Mice eliminate (3)H 4,6,4'-TMA mostly through the urine, but also through the faeces. Two metabolites were identified in the urine and serum of the treated mice, one of which proved to be a derivative of 4,6,4'-TMA, formed by hydrogenation of the double 4',5' bond of the furocoumarin nucleus.