5-Chlorouracil is a chlorinated derivative of the pyrimidine nucleoside base uracil . In vivo, it is converted into chlorodeoxyuridine, which is mutagenic and genotoxic.1 Uracil is chlorinated at the 5 position in a cell-free myeloperoxidase, peroxide, and chloride system in which hypochlorous acid is formed.2 5-Chlorouracil has been found in human neutrophils stimulated with phorbol 12-myristate 13-acetate in vitro and in inflammatory human exudate isolated from sites of superficial infection. Levels of 5-chlorouracil are increased in exudate isolated from the site of inflammation in a rat model of carrageenan-induced inflammation and in patient-derived human atherosclerotic aortic tissue.3,4References 5-Chlorouracil is a chlorinated derivative of the pyrimidine nucleoside base uracil . In vivo, it is converted into chlorodeoxyuridine, which is mutagenic and genotoxic.1 Uracil is chlorinated at the 5 position in a cell-free myeloperoxidase, peroxide, and chloride system in which hypochlorous acid is formed.2 5-Chlorouracil has been found in human neutrophils stimulated with phorbol 12-myristate 13-acetate in vitro and in inflammatory human exudate isolated from sites of superficial infection. Levels of 5-chlorouracil are increased in exudate isolated from the site of inflammation in a rat model of carrageenan-induced inflammation and in patient-derived human atherosclerotic aortic tissue.3,4 References
1,1'-Ethylidene-bis-(L-tryptophan) is a potential impurity in L-tryptophan commercial products, promoting EoL-3 eosinophilic leukemia cell proliferation, enhancing eosinophil cationic protein release from human peripheral blood eosinophils, and boosting IL-5 production in human T cells. At 40 µg kg, it triggers fascia thickening, mast cell infiltration, inflammation, and fibrosis in mouse superficial adipose and panniculus carnosus tissues, serving as an eosinophilia-myalgia syndrome research model.