1; Heat extracts of mature mycelia of streptomycin-producing strains of Sfreptomyces contain two compounds which, when incubated with arginine-guanidino-‘*C plus a crude enzyme preparation from S. griseus ATCC 12475 containing a&nine: X amidinotrausferase, give products detected as radioactive Peaks I and II. Heat extracts from S. bluensis var. bluensis, which synthesizes bluensomycin, a monogu...

Absorption, metabolism, and excretion of [14C]viramidine, a prodrug of ribavirin, were studied in humans following a single oral dose (600 mg). Viramidine was rapidly absorbed, with a time to maximum concentration of the drug in plasma of 1.5 h. Viramidine and ribavirin accounted for only 4.3% and 42% of plasma area under the concentration-time curve (AUC) for radioactivity, respectively, indic...

The reductive metabolism of a series of 3-(indol-1-yl)-1,2-benzisoxazoles was examined in vitro using rat liver microsomes. 3-(Indol-1-yl)-1,2-benzisoxazole was reduced to the corresponding amidine (resulting from N-O bond cleavage) under anaerobic conditions. The reaction required viable microsomes and NADPH and was inhibited by carbon monoxide, air, and ketoconazole, suggesting the involvemen...