The Pharmacological Activities of the Metabolites ofN‐[(Trimethylamineboryl)‐Carbonyl]‐L‐Phenylalanine Methyl Ester

The metabolites of N-[(trimethylamineboryl)-carbonyl]-L-phenylalanine methyl ester 1 proved to be active in a number of pharmacological screens where the parent had previously demonstrated potent activity. The proposed metabolites demonstrated significant activity as cytotoxic, hypolipidemic, and anti-inflammatory agents. In cytotoxicity screens several of the proposed metabolites afforded better activity than the parent compound against the growth of suspended and solid tumor cell lines. Evaluation of in vivo hypolipidemic activity demonstrated that the proposed metabolites of 1 were only moderately active and were generally less effective than the parent compound. Interestingly, L-phenylalanine methyl ester hydrochloride 3, which contains no boron atom, demonstrated equivalent hypolipidemic activity as the parent at 8 mg/kg/day in CF(1) male mice. As anti-inflammatory agents the proposed metabolites demonstrated variable capacities to reduce foot pad inflammation. These compounds were similarly effective as the parent 1 at blocking local pain and were generally better than the parent at protecting CF(1) male mice from LPS induced sepsis.