Excretion of methylproscillaridin in patients with a biliary fistula

Summary

Four patients with a biliary fistula received 0.5 mg³H-methylproscillaridin as a single oral dose. 55% of the dose was excreted in bile, 16% in urine and 3% in faeces. More than 60% of the radioactivity excreted in bile and urine appeared within the first 24 hours. 78% of the radioactivity in bile consisted of CHCl₃-insoluble metabolites of methylproscillaridin, incubation of which with β-glucuronidase led to splitting off glucuronic acid from almost 80%. Methylproscillaridin can be regarded as the principal conjugated compound. TLC-separation of CHCl₃-soluble compounds from bile showed identical running of radioactivity with methylproscillaridin, proscillaridin and scillarenin and three unknown metabolites P₁, P₂, and P₃. In urine the CHCl₃-soluble fraction averaged 16% to 34% of the total amount and was identified as methylproscillaridin, proscillaridin, scillarenin, P₂ and P₃. The relative composition of the total radioactivity in faeces amounted to 77% methyl-proscillardidin, 4% scillarenin and 12% polar metabolites.