FORMATION OF ISOINDOLE DERIVATIVES OF SULFIDOPEPTIDE LEUKOTRIENES BY REACTION WITH ORTHO-PHTHALALDEHYDE AND SEPARATION BY REVERSE PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A method is described for the formation of fluorescent conjugates of the sulfidopeptide leukotrienes (LTC//4, LTD//4, and LTE//4) by reaction of the primary amine moiety of these metabolites with o-phthalaldehyde. Separation of the fluorescent derivatives was achieved by reverse-phase high performance liquid chromatography in less than 30 minutes using a convex gradient of methanol-50 mM Na Acetate-5% Tetrahydrofuran pH 5. 5. Detection limits realized under the conditions described were 0. 35 ng, 3. 8 ng and 3. 7 ng for LTC//4, LTD//4, and LTE//4, respectively. This represents an increased sensitivity over detection of these metabolites by ultra-violet spectroscopy.