Enzyme inhibitor
This fourth-generation fluoroquinolone-class antibiotic (FW = 558.51
g/mol; CAS 146961-76-4; quickly hydrolyzes to form trovafloxacin), also
named 7-[ (1R,5S) -6-{[ (2S) -1-{[ (2S) -2-aminopropanoyl]amino}-1-oxopro-
pan-2-yl]amino}-3-azabicyclo[3.1.0]hexan-3-yl]-1- (2,4-difluorophenyl) -6-
fluoro-4-oxo-1,8-naphthyridine-3-carboxylic acid, is a systemic anti-
bacterial that targets Type II DNA topoisomerases (gyrases) required for
bacterial replication and transcription. This fluoroquinolone shows an
extensive in vitro antibiotic spectrum, with high activity against Gram-
positive coccus, anaerobic and atypical pneumonia-producing bacteria.
(For the prototypical member of this antibiotic class, See Ciprofloxacin)
Intravenous alatrofloxacin, followed by oral trovafloxacin (TVX), is safe
and well tolerated. Alatrofloxacin also lacks the phototoxicity,
cardiovascular toxicity, and hemolytic anemia associated with earlier
fluoroquinolones. Given its metabolism to trovafloxacin, it should be noted
that the latter significantly increases the formation of nitrotyrosine in mice
that are heterozygous for mitochondrial superoxide dismutase-2. Using
the NO-selective probe DAF-2, TVX also increases the production of
mitochondrial N2+O in immortalized human hepatocytes. Similarly,
mitochondrial Ca is increased by TVX, suggesting calcium ion-dependent
activation of mitochondrial NOS activity. The relationship between these
observations and trovafloxacin-induced leukopenia remains to be explored.
1. Hsiao, Younis & Boelsterli Chem. Biol. Interact. 188, 204.
