We have obtained evidence that acylperoxo-iron(III) porphyrin complexes 1a are involved as reactive hydroxylating intermediates in the hydroxylation of alkanes by m-chloroperoxybenzoic acid (m-CPBA) catalyzed by electron-deficient iron(III) porphyrin complexes containing chloride as an anionic axial ligand in a solvent mixture of CH2Cl2 and CH3CN at −40 °C. In addition to the intermediacy of 1a, oxoiron(IV) porphyrin cation radical complexes 2 are formed as the reactive hydroxylating intermediates in the alkane hydroxylations by m-CPBA catalyzed by the iron(III) porphyrin complexes containing triflate (CF3SO3 -) as an anionic axial ligand under the same reaction conditions. In line with the recent proposal by Newcomb, Coon, Vaz, and co-workers for cytochrome P-450 reactions, these results suggest that two distinct electrophilic oxidants such as 1a and 2 effect the alkane hydroxylations in iron porphyrin models, depending on the reaction conditions such as the nature of the anionic axial ligands of iron(III) porphyrin complexes.

Purpose: To compare the efficacy of intravitreal gatifloxacin with intravitreal vancomycin in the treatment of Staphylococcus epidermidis endophthalmitis in a rabbit model. Methods: Albino rabbits (n=30), infected with an intravitreal inoculum of S. epidermidis (10 5 colony forming unit/0.1 mL), were divided into 6 groups (n=5). Groups I and IV received 200 µg/0.1 mL of intravitreal gatifloxacin, and groups II and V were injected 1000 µg/0.1 mL of vancomycin intravitreally. Intravitreal balanced salt solutions (untreated control) were given to Groups III and VI. Intravitreal antibiotic therapy commenced 24 hours after bacterial inoculation. The bactericidal efficacy was determined by electroretinography (ERG), clinical grading, bacterial culture of vitreous aspirates and histopathologic grading. ERGs and clinical gradings were performed only for groups I, II, and III and bacterial cultures were done only for groups IV, V, and VI. Results: Eyes in the gatifloxacin groups showed similar appearance to those in the vancomycin treated groups clinically, histologically, and functionally as proved with ERG. All aspirates from the gatifloxacin and vancomycin groups were culture-negative at 5 days after bacterial inoculation, whereas all eyes in the untreated control group were culture-positive. Conclusions: This study demonstrated that intravitreal injection of 200 µg /0.1mL gatifloxacin appeared to be equally effective compared to intravitreal 1000 µg /0.1 mL vancomycin in the treatment of S. epidermidis endophthalmitis. If proven safe and efficacious after further study in humans, intravitreal injection of gatifloxacin could be considered an effective alternative to vancomycin for the treatment of S. epidermidis endophthalmitis.

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