Isosulfazecin

Isosulfazecin (iSZ) is a novel β-lactam antibiotic produced by Pseudomonas acidophilus sp., synthesized in a nutrient solution supplemented with glycerol and sodium thiosulfate under aerobic conditions in parallel with bacterial growth. It is purified by chromatography and crystallization from aqueous methanol. Physicochemical analysis determined its molecular formula to be C12H20N4O9S, showing a structure with a β-lactam ring, methoxyl and sulfonate groups. Acid hydrolysis yields L-alanine and D-glutamic acid. iSZ is a diastereomer of sulfadiazine and exhibits moderate activity against both gram-positive and gram-negative bacteria, but potent activity against bacteria resistant to β-lactam antibiotics[1].