Human moricizine metabolism. I. Isolation and identification of metabolites in human urine.

1. Using synthetic standards and/or spectral data, seven moricizine metabolites were structurally identified in human urine. Two novel metabolites were identified as phenothiazine-2-carbamic acid and ethyl [10-(3-aminopropionyl) phenothiazin-2-yl] carbamate. Two novel human moricizine metabolites, 2-amino-10-(3-morpholino-propionyl) phenothiazine, a previously identified dog metabolite, and 2-aminophenothiazine, a previously identified rat metabolite, were also identified. Three additional human metabolites, phenothiazine-2-carbamic acid ethyl ester sulphoxide (P2CAEES), moricizine sulphoxide, and ethyl ¿10-[N-(2'-hydroxyethyl)3-aminopropionyl] phenothiazin-2-yl¿ carbamate, all previously described in the literature, were observed. 2. Both 2-amino-10-(3-morpholinopropionyl) phenothiazine and ethyl [10-(3-aminopropionyl) phenothiazin-2-yl] carbamate, and possibly ethyl ¿10-[N-(2'-hydroxyethyl) 3-aminopropionyl]phenothiazin-2-yl¿ carbamate, possess the structural characteristics thought to be necessary for class 1 antiarrhythmic activity.