6-FLUOROPYRIDOXAL POLYMER CONJUGATES - NOVEL F-19 PH INDICATORS FOR MAGNETIC-RESONANCE SPECTROSCOPY

Fluorinated macromolecular probes (6-fluoropyridoxal-polymer conjugate s) have been synthesized and characterized as potential pH indicators for magnetic resonance spectroscopy and imaging applications. The F-19 pH sensor 2-fluoro-5-hydroxy-3-(hydroxymethyl)-6-methyl-4- pyridineca rboxaldehyde (8-fluoropyridoxal; 2) has been conjugated to carrier mol ecules (polyamino dextran, polylysine, and albumin) by reductive alkyl ation for enhanced vascular retention and tissue targeting. The pH ind icator polymer conjugates were purified by exhaustive dialysis and iso lated in good yields (66-84%). The 6-fluoropyridoxal-polymer conjugate s exhibit excellent F-19 pH sensitivity and pK(a) suitable for in vivo studies. The potential application of these polymeric indicators has been demonstrated in whole blood. These novel macromolecular pK probes offer a new approach for studying tissue physiology.