[Identification of two S-containing metabolites of 1-allyl-3,5-diethyl-6-chlorouracil in rabbit urine (author's transl)].

The synthesis of 2-14C-1-allyl-3,5-diethyl-6-chlorouracil (2-14C-Aclu; Acluracil) is described. After application in rabbits, 2-14C-Aclu is biotransformed in one S-free major metabolite I and two S-containing minor metabolites II and III, which are more polar than Aclu. The metabolites have been isolated and purified by thick layer-, column- and gaschromatography. With the help of 1N-NMR- and mass spectroscopy, metabolite II could be identified as 1-allyl-3-ethyl-5-(2-hydroxy ethyl)-6-methylmercaptouracil and metabolite III as 1-allyl-3,5-diethyl-6-methylmercaptouracil. The introduction of methylmercapto group (-SCH3) in metabolites II and III represents a new biochemical pathway which to the best of our knowledge has not been reported in the literature up to now.