Accelerated Transformation and Deactivation of Erythromycin in Superheated Water. 2. Transformation Reactions and Bioassays

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• 作者：Michelle N. Butler and Walter J. Weber Jr.
• 刊名：Environmental Science & Technology
• 出版年：2005
• 出版时间：April 1, 2005
• 年：2005
• 卷：39
• 期：7
• 页码：2301 - 2306
• 全文大小：170K
• 年卷期：v.39,no.7(April 1, 2005)
• ISSN：1520-5851

文摘

The work presented in this second part of a two-partseries on the accelerated transformation of erythromycinin superheated water focuses on the chemical nature andresultant antimicrobial implications of the overall reactionobserved. Analyses of reactor effluents employing infraredspectroscopy and liquid chromatography/mass spectrometryindicated that the initial step in the decompositionpathway is one of dehydration. Subsequent hydrolysis inthe presence of an acetate buffer appeared to result in theloss of the sugar cladinose. Chemical transformationunder superheated conditions was tied to the loss ofantibiotic function by an agar dilution test. The sensitivityof this test was verified by determination of the minimuminhibitory concentration (MIC) of erythromycin correspondingto each of two test microorganisms. MIC values for theselected strains of Escherichia coli and Bacillus subtiliswere 35 and 0.5 mg/L, respectively. To relate the loss ofantimicrobial activity to increased reaction temperature andthus to increased extent of parent compound transformationto microbially benign intermediates, bioassays using E.coli as test microorganism were performed on flow reactoreffluents resulting from reaction of initial erythromycinconcentrations of 75-150 mg/L.