β-Apo-oxytetracycline

β-Apooxytetracycline is a potential impurity found in commercial preparations of oxytetracycline. β-Apooxytetracycline is a degradation product formed from oxytetracycline via acid hydrolysis. It has a relative potency of 0.1 compared with oxytetracycline for inhibiting the growth of aerobic sludge bacteria, an MIC₅₀ value of 32 mg/L for tetracycline-sensitive strains of Pseudomonas, and MIC₅₀ values of greater than 32 mg/L for tetracycline-sensitive strains of Agrobacterium, Moraxella, and Bacillus, as well as tetracycline-resistant strains of E. coli. β-Apooxytetracycline (10 mg/kg) is toxic to rats, decreasing body weight, disrupting blood cell counts, and inducing hepatocyte necrosis.

yellow-brown to brown powder

β-Apooxytetracycline is a degradation product of oxytetracycline formed under acidic conditions. After initial dehydration to anhydrooxytetracycline, it undergoes an internal cyclisation of the C5-OH to the C12 ketone. The resulting cleavage of the C12-C12a bond generates two isomers, α- and β-apooxytetracycline. β-Apooxytetracycline is an important standard for monitoring oxytetracycline stability.

β-Apooxytetracycline is a degradation product of oxytetracycline formed under acidic conditions. An initial dehydration to anhydrooxytetracycline then undergoes an internal cyclisation of the C5-OH to the C12 ketone. The resulting cleavage of the C12-C12a bond generates two isomers, α- and β-apooxytetracycline. β-apooxytetracycline is an important standard for monitoring oxytetracycline stability.

Oxytetracycline metabolite (absolute stereochemistry unknown)

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