Cefsulodin

Rationale: The structural identification of impurities in cephalosporins has been reported. However, to the best of our knowledge, there was no report on the impurities of cefsulodin sodium, which is necessary for the quality control. Thus, the aim of this study was to separate and characterize the impurities in cefsulodin sodium raw material using liquid chromatography/tandem mass spectrometry (LC/MS/MS). Methods: The analytes were separated on a Kromasil 100-5C18 column (4.6 mm × 250 mm, 5 μm) using a gradient elution with a mobile phase consisting of 1% ammonium sulphate aqueous solution and acetonitrile in the first dimension. The separation in the second dimension was carried on a Shimadzu Shim-pack GISS C18 column (50 mm × 2.1 mm, 1.9 μm) with a mobile phase consisting of 10 mM ammonium formate solution and methanol. Results: The fragmentation behaviors of cefsulodin and its impurities were studied and the structures of the impurities were deduced based on the MSn data. The structures of ten unknown impurities were proposed based on the work carried out in this study. The degradation behaviors of cefsulodin sodium were also studied. This revealed that cefsulodin sodium should be stored in a dry, cool and dark closed container. Conclusions: Based on the characterization of impurities, this study not only revealed the mechanism by which impurities were produced, thus providing guidance to pharmaceutical companies for manufacturing process improvement and impurity control, but also provided a scientific basis for further improvement of official monographs in pharmacopoeias.

Background microorganism growth on Chromogenic Coliform Agar (CCA) can be challenging. For this reason, a new alternative method with a Cefsulodin/Vancomycin (CV)-supplemented CCA should be developed in this study. CCA supplemented with CV was validated according to ÖNORM EN ISO 16140-4:2021 using water from natural sources in Styria, Austria. Results show that the alternative method using the supplemented CCA has similar values in relation to sensitivity (82.2%), specificity (98.6%) and higher selectivity (59%) compared to the reference method. Repeatability and reproducibility were acceptable for the alternative method and showed similar results with the reference method. The alternative method shows a very low false positive rate and a low false negative rate paired with good performance regarding the inclusion study. The exclusion study shows the advantage of our method by suppressing background microorganisms and facilitating the process of enumeration of Escherichia coli and other coliform bacteria on CCA plates. Aeromonas hydrophila and Pseudomonas aeruginosa growth was inhibited using the supplement. To conclude, the coliform CV selective supplement combined with CCA is an appropriate tool for coliform bacteria detection in water samples.

mPTPB is a virulent phosphatase from Mycobacterium tuberculosis and a promising therapeutic target for tuberculosis. To facilitate mPTPB-based drug discovery, we identified α-sulfophenylacetic amide (SPAA) from cefsulodin, a third generation β-lactam cephalosporin antibiotic, as a novel pTyr pharmacophore for mPTPB. Structure-guided and fragment-based optimization of SPAA led to the most potent and selective mPTPB inhibitor 9, with a K i of 7.9 nM and more than 10,000-fold preference for mPTPB over a large panel of 25 phosphatases. Compound 9 also exhibited excellent cellular activity and specificity in blocking mPTPB function in macrophage. Given its novel structure, modest molecular mass, and extremely high ligand efficiency (0.46), compound 9 represents an outstanding lead compound for anti-TB drug discovery targeting mPTPB.