THE DISPOSITION, TISSUE DISTRIBUTION, AND CELLULAR-TRANSPORT OF N-[[(TRIMETHYLAMINO)BORYL]CARBONYL]-L-PHENYLALANINE METHYL-ESTER IN CF1 MICE

The disposition and tissue distribution of C-14-labeled N-[[(trimethylamino)boryl]carbonyl]-L-phenylalanine methyl ester (1) was determined in CF1 mice following iv, po, and ip administration. Compound 1 was found to undergo rapid and extensive metabolism, and the majority of the radioactivity was found in the skin and carcass regardless of the route of administration. Approximately 55% of the radioactivity was recovered in urine and feces after 78 h; however, excretion via these routes was not complete. Degradation of compound 1 occurred at the amide bond at low pH (0.8) but at the ester bond a physiological pH. This difference in degradation was reflected in elevation of the blood radioactivity levels after po administration compared to ip and iv administration.