Lipoxin MaxSpec^® LC-MS Mixture

This mixture contains several lipoxins and their precursor, arachidonic acid (Item No. 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.^1,2,3,4 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 (Item No. 90410) and B₄ (Item No. 90420).^1,5,6 15(R)-Lipoxin A₄ (Item No. 90415) is derived from the aspirin-triggered formation of 15(R)-HETE (Item No. 34710) from arachidonic acid.^7,8

WARNING This product is not for human or veterinary use.

1. Serhan, C.N., Hamberg, M., and Samuelsson, B. Lipoxins: Novel series of biologically active compounds formed from arachidonic acid in human leukocytes. Proc. Natl. Acad. Sci. USA 81(17), 5335-5339 (1984).

2. Ramstedt, U., Serhan, C.N., Nicolaou, K.C., et al. Lipoxin A-induced inhibition of human natural killer cell cytotoxicity: Studies on stereospecificity of inhibition and mode of action. J. Immunol. 138(1), 266-270 (1987).

3. Maddox, J.F., and Serhan, C.N. Lipoxin A₄ and B₄ are potent stimuli for human monocyte migration and adhesion: Selective inactivation by dehydrogenation and reduction. J. Exp. Med. 183(1), 137-146 (1996).

4. Papayianni, A., Serhan, C.N., and Brady, H.R. Lipoxin A₄ and B₄ inhibit leukotriene-stimulated interactions of human neutrophils and endothelial cells. J. Immunol. 156(6), 2264-2272 (1996).

5. Serhan, C.N., Nicolaou, K.C., Webber, S.E., et al. Lipoxin A. Stereochemistry and biosynthesis. The Journal of Biological Chemisty 261(35), 16340-16345 (1986).

6. Serhan, C.N., Hamberg, M., Samuelsson, B., et al. On the stereochemistry and biosynthesis of lipoxin B. Proc. Natl. Acad. Sci. USA 83(7), 1983-1987 (1986).

7. Clària, J., Lee, M.H., and Serhan, C.N. Aspirin-triggered lipoxins (15-epi-LX) are generated by the human lung adenocarcinoma cell line (A549)-neutrophil interactions and are potent inhibitors of cell proliferation. Mol. Med. 2(5), 583-596 (1996).

8. Clària, J., and Serhan, C.N. Aspirin triggers previously undescribed bioactive eicosanoids by human endothelial cell-leukocyte interactions. PNAS USA 92(21), 9475-9479 (1995).