3-Bromotyrosine-13C9,15N (trifluoroacetate salt)

3-Bromotyrosine-13C9,15N is intended for use as an internal standard for the quantification of 3-bromotyrosine (Item No. 22606) by GC- or LC-MS.{39012,39010} 3-Bromotyrosine is a product of protein oxidation found after activation of eosinophils during an allergic response.{39007,39008,39010} It has been used as a marker of eosinophil peroxidase-induced protein oxidation in vitro and in vivo.{39008,39011} In addition to its production in eosinophils, 3-bromotyrosine is found at 5-fold higher levels in peritoneal exudate from mice infected with K. pneumoniae compared with uninfected animals, suggesting neutrophils release higher levels of oxidized products during inflammation.{39012} In a human study, 3-bromotyrosine was increased in allergen-challenged lung samples from subjects with allergen-induced asthma.