Lipoxin MaxSpec(R) LC-MS Mixture

This mixture contains several lipoxins and their precursor, arachidonic acid (Cay-90010). The mixture is supplied in an amber ampule in which the headspace has been purged with argon to prevent lipid oxidation. This product has been designed for direct use in LC-MS applications. The solution may be serially diluted for preparation of calibrators and QC standards and/or used directly as a system suitability standard or tuning standard. After opening, we recommend that the mixture be transferred immediately to a 1 ml glass screw cap vial, to prevent solvent evaporation, and stored at -80°C. The mixture should be discarded after multiple freeze/thaw cycles.The fatty acids in this mixture represent the metabolic cascade of the lipoxins, a family of lipid mediators that are generated at the site of vascular and mucosal inflammation where they down-regulate polymorphonuclear leukocyte recruitment and function. Lipoxins are produced by human leukocytes via the oxygenation of arachidonic acid by either 15- or 5-lipoxygenase, which forms 15-HETE or 5-HETE intermediates before subsequent metabolism to lipoxin A4 (Cay-90410) and B4 (Cay-90420). 15(R)-Lipoxin A4 (Cay-90415) is derived from the aspirin-triggered formation of 15(R)-HETE (Cay-34710) from arachidonic acid.Formulation: (Request formulation change), A solution in ethanol (100 ng/ml of each compound).