Hydrolysis of an orally active platelet inhibitory prostanoid amide in the plasma of several species

Hydroxamates: relationships between structure and plasma stability

Hydroxamates are valuable tools for chemical biology as well as interesting leads for medicinal chemistry. Although many hydroxamates display nanomolar activities against metalloproteases, only three hydroxamates have reached the market, among which is the HDAC inhibitor vorinostat. Failures in development are generally attributed to lack of selectivity, toxicity, or poor stability. To help medicinal chemists with respect to plasma stability, we have performed the first and preliminary study on structure-plasma stability for hydroxamates. We define some structural rules to predict or improve the plasma stability in the preclinical stage.

Pharmacokinetics and metabolism of UK-383,367 in rats and dogs: A rationale for long-lived plasma radioactivity

UK-383,367 (5-{(1R)-4-cyclohexyl-1-[2-(hydroxyamino)-2-oxoethyl]butyl}-1,2,4-oxadiazole-3-carboxamide) is a novel procollagen C-proteinase inhibitor evaluated for the treatment of post-surgical dermal scarring. It is extensively metabolized in rat and dog absorption, distribution, metabolism and excretion studies, and a metabolic pathway for UK-383,367 was determined. A long-lived metabolite was identified in dog plasma. Data indicate that this metabolite results from the oxadiazole ring-cleavage-producing oxamic acid, oxamide and oxalic acid. Ion exclusion chromatography was used to identify these polar metabolites, which were unretained on a standard reversed-phase high-performance liquid chromatography system. The oxamide metabolite was identified as the long-lived radioactivity, which was observed in dog plasma.