DESIGN, SYNTHESIS AND CHARACTERIZATION OF A NOVEL FLUORESCENT-PROBE FOR NITRIC-OXIDE (NITROGEN MONOXIDE)

The iron(II) complex of quinoline pendant cyclam was designed as a mim ic of the activation site of guanylate cyclase and synthesized as a fl uorescent probe for nitric oxide (NO). Fe(II) ion shifted the excitati on and emission maxima of the pendant fluorophore to longer wavelength s, and the fluorescence intensity was greatly increased. NO from NO-re leasing agents quenched the fluorescence effectively. Nitrite, which i s a metabolite of NO, did not affect the fluorescence of the complex. Cyanate also did not affect the spectral change of the complex with NO . NO, as low as mu M, can be determined spectrofluorimetrically using 200 mu M reagent. This is the first example of a fluorescent probe for NO which recognizes the molecule directly. (C) 1998 Elsevier Science B.V.