A very mild and quantitative oxidation of cephalosporins with dimethyldioxirane

Gunda, T. E.; Tamás, László; Sályi, Szabolcs; Nemes, Csaba; Sztaricskai, Ferenc

doi:10.1016/0040-4039(95)01411-a

Cited by 12 publications

(13 citation statements)

References 8 publications

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“…13,14 In this context, it is well known that alkyl sulfides undergo a fast reaction with 1 equiv of DMD to give the corresponding sulfoxide; in the presence of an excess of the oxidation reagent, sulfoxides are converted into sulfones. [19][20][21][22][23] The high reactivity of sulfides and sulfoxides with DMD makes possible the chemoselective oxidation of those moieties in the presence of a wide variety of substituents and functional groups, which include metal complexes. 24 Similarly to what occurs with sulfides, di-and tri-sulfides are readily oxidized by DMD to give the corresponding sulfones.…”

Section: Resultsmentioning

confidence: 99%

Complete Elimination of Interferences in the Organotin Determination by Oxidation with Dimethyldioxirane Combined with Alumina Cleanup

et al. 1998

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Most of the analytical procedures used in organotin (OT) speciation from sediment involves the Grignard derivatization reaction followed by a cleanup step and a desulfuration reaction since sulfur and/or sulfur species interfere with OT determination by GC/MS or GC-FPD. However, alkyl sulfides are generated from the coextracted elemental sulfur, and they are not removed by conventional desulfurization procedures. We propose here a method based on the oxidation of all the sulfur species with dimethyldioxirane (DMD) to sulfones or sulfur oxides. While sulfones are easily eliminated by alumina adsorption chromatography because they have higher polarity than OTs, the sulfur oxides are spontaneously evaporated. The DMD chemoselectivity favors the oxidation of sulfur compounds to sulfones in a few minutes, whereas OTs remain unreacted. In addition, the excess DMD is easily removed by evaporation under a nitrogen stream before the Al(2)O(3) cleanup step. The effectiveness of the desulfurization reaction combined with the cleanup step is demonstrated for a variety of sediment samples containing up to 3.1% of elemental sulfur, which is completely removed by adding 0.6 molar equiv of DMD. No statistical differences in the OT distribution pattern throughout the DMD intermediate oxidation steps were observed.

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Section: Resultsmentioning

confidence: 99%

Complete Elimination of Interferences in the Organotin Determination by Oxidation with Dimethyldioxirane Combined with Alumina Cleanup

et al. 1998

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“…Oxidation Sites within the Core Structure. The oxidative transformations of some cephalosporin antibiotics have been identified, [25][26][27][28][29]38 but those of the core structure compound have not yet been elucidated. Herein, we investigated the oxidation sites in the core structure by exploring its transformation byproducts during MnO 2 oxidation.…”

Section: Environmental Science and Technologymentioning

confidence: 99%

“…Several studies investigated the oxidative transformations of cephalosporins and β-lactam antibiotics, and the results indicated that these compounds can undergo hydrolytic cleavage or oxidation at the cephem ring during different oxidation processes involving ClO 2 , dimethyldioxirane, hydrogen peroxide, and chloramine-T. − The pathways proposed in these studies suggest that oxidation mainly occurs at two possible positions. Either the sulfur on the core structure is oxidized to sulfoxide or the amide bond in the β-lactam ring is broken.…”

Section: Introductionmentioning

confidence: 99%

Substructure Reactivity Affecting the Manganese Dioxide Oxidation of Cephalosporins

Hsu

Kuo

Chen

et al. 2018

Environ. Sci. Technol.

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Cefotaxime (CTX), cephalexin (CFX), cephradine (CFD), cephapirin (CFP), and cefazolin (CFZ) were selected as target cephalosporin antibiotics to study their oxidative transformation by δ-MnO. Although they all have the same core structure (7-aminodesacetoxycephalosporanic acid), very different MnO oxidation rates were observed at pH 4 (the initial reaction rate constant k ranged from 0.014 to 2.6 h). An extensive investigation of the substructure compounds and byproduct analysis revealed that the oxidation mainly occurred at the following two sites on the core structure: (1) the sulfur atom in the cephem ring and (2) the carbon-carbon double bond (C═C) and its proximal carboxylic acid group. In the case of (2), when there is an acetyloxymethyl group at the C-3 position of the core structure, the formation of the keto-sulfone byproducts was inhibited. The overall results indicated that a substituent at the C-3 position could stabilize the core structure, which would result in a decrease in the oxidation rate; however, a substituent at the amine position of the core structure might affect the overall degradation rate of the cephalosporin, depending on its reactivity with MnO. Thus, the apparent reaction rates varied widely in the trend of CTX > CFP > CFD > core structure ≈ CFX > CFZ. The mechanistic elucidation can also help explain the degradation rates of cephalosporin antibiotics in other oxidation processes.

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“…Their sulfur atoms were chemoselectively oxidized with isolated dimethyldioxirane (1). 59,60 Neither the double bond nor the nitrogen atom was oxidized even with a large excess of the oxidant.…”

Section: Methodsmentioning

confidence: 99%

Dioxirane Oxidation of Sulfur‐Containing Organic Compounds

Lévai

2004

ChemInform

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Dedicated to Professor Branko AbstractThis short review describes the utilization of dioxiranes as convenient and extremely efficient electrophilic oxidants for the selective oxidation of sulfur-containing organic compounds. Relevant examples are included to illustrate the chemoselective and stereoselective oxidations of substances with several sites of oxidation. Electrophilic character of the dioxiranes is shown via the oxidation of compounds with two sulfur heteroatoms.

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A very mild and quantitative oxidation of cephalosporins with dimethyldioxirane

Cited by 12 publications

References 8 publications

Complete Elimination of Interferences in the Organotin Determination by Oxidation with Dimethyldioxirane Combined with Alumina Cleanup

Complete Elimination of Interferences in the Organotin Determination by Oxidation with Dimethyldioxirane Combined with Alumina Cleanup

Substructure Reactivity Affecting the Manganese Dioxide Oxidation of Cephalosporins

Dioxirane Oxidation of Sulfur‐Containing Organic Compounds

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