T. Morimura et al., PHOTODEGRADATION PRODUCTS OF A NEW ANTIBACTERIAL FLUOROQUINOLONE DERIVATIVE, ORBIFLOXACIN, IN AQUEOUS-SOLUTION, Chemical and Pharmaceutical Bulletin, 45(2), 1997, pp. 373-377
A new antibacterial fluoroquinolone derivative, orbifloxacin (ORFX), i
s decomposed photochemically in aqueous solution, When ORFX solution w
as irradiated with a chemical lamp or sunlight, three major photodegra
dation products were isolated by preparative HPLC. These degradation p
roducts were identified by electron-impact mass spectrometry, liquid-s
econdary-ion mass spectrometry and H-1-NMR spectroscopy. Moreover, the
photodegradation pathway was investigated by a similar study using se
veral fluoroquinolone derivatives which were presumed to be the interm
ediates of the photoreaction of ORFX, Consequently, it was found that
two main photochemical reactions, the decomposition of the dimethylpip
erazinyl moiety and the elimination of the cyclopropyl group, take pla
ce in ORFX, The detected structures of photodegradation products and t
he photodegradation studies of the postulated intermediates suggested
that the photodecomposition of the dimethylpiperazinyl ring at the 7-p
osition and the elimination of the cyclopropyl group at the 1-position
occurred concurrently with the release of fluorine at the 8-position.