Synthesis and antibacterial activity of the metabolites of 9-fluoro-6,7-dihydro-8-(4-hydroxy-1-piperidyl)-5-methyl-1-oxo-1H,5H- benzo[i,j]quinolizine-2-carboxylic acid (OPC-7251).

The metabolites of 9-fluoro-6,7-dihydro-8-(4-hydroxy-1-piperidyl)-5-methyl-1-oxo-1H,5H- benzo[i,j]quinolizine-2-carboxylic acid (OPC-7251) (1), which has a potent antibacterial activity against gram-positive bacteria, characteristically Propionibacterium acnes, were synthesized to confirm their structures and to examine their antibacterial activity. The structures of three major metabolites (2, 3a and 4) were identified by means of comparison with the synthetic compounds. The antibacterial activity of the metabolites (2, 3a and 4) was found to be lower than that of 1.