Photodegradation products of a new antibacterial fluoroquinolone derivative, orbifloxacin, in aqueous solution.
A new antibacterial fluoroquinolone derivative, orbifloxacin (ORFX), is decomposed photochemically in aqueous solution. When ORFX solution was irradiated with a chemical lamp or sunlight, three major photodegradation products were isolated by preparative HPLC. These degradation products were identified by electron-impact mass spectrometry, liquid-secondary-ion mass spectrometry and 1-H-NMR spectroscopy. Moreover, the photodegradation pathway was investigated by a similar study using several fluoroquinolone derivatives which were presumed to be the intermediates of the photoreaction of the ORFX. Consequently, it was found that two main photochemical reactions, the decomposition of the dimethylpiperazinyl moiety and the elimination of the cyclopropyl group, take place in ORFX. The detected structures of photodegradation products and the photodegradation studies of the postulated intermediates suggested that the photodecomposition of the dimethylpiperazinyl ring at the 7-position and the elimination of the cyclopropyl group at the 1-position occurred concurrently with the release of fluorine at the 8-position.
Morimura
T
T
Department of Chemical Analysis, Dainippon Pharmaceutical Co., Ltd., Osaka, Japan.
Nobuhara
Y
Y
Matsukura
H
H
D000890:Anti-Infective Agents / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry; D012996:Solutions
D000890:Anti-Infective Agents; D012996:Solutions; D002939:Ciprofloxacin; C095163:orbifloxacin