Effect of sparteine and quinidine on the metabolism of methoxyphenamine by Cunninghamella bainieri.

1. The fungus C. bainieri, incubated for 7 days with methoxyphenamine alone or in combination with either sparteine or quinidine, gave N-desmethylmethoxyphenamine and its N-acetyl conjugate as major metabolites, while O-desmethylmethoxyphenamine, 5-hydroxymethoxyphenamine and 2-hydroxyamphetamine were produced in lesser amounts. In addition, 1-(2-hydroxyphenyl)-2-aminopropane, 1-hydroxy-1-(2-methoxyphenyl)-2-propanone, beta-hydroxymethoxyphenamine, and 1-(5-hydroxy-2-methoxyphenyl)-2-aminopropane were tentatively identified as minor components of the fungal biotransformation of methoxyphenamine. 2. As observed in mammalian systems, the addition of either sparteine or quinidine decreased the rate and extent of methoxyphenamine biotransformation. 3. C. bainieri may be a useful model for drug interaction studies.