Acta Pharm. 48 (1998) 269-279

Isopyridoxal-4'-fluorophosphate: Synthesis and preliminary study of coenzyme
influence on aspartate aminotransferase catalytic activity

LORENA HONOVIC,¹ JULIJA MATIJEVIC-SOSA,^2* and   MIRNA FLÖGEL-MRŠIC² 

¹Clinical Laboratory, General Hospital Pula,  Pula, Croatia
² Department of Biochemistry and Molecular Biology,  Faculty of Pharmacy and Biochemistry,
  University of Zagreb,  Zagreb, Croatia 

The synthesis of isopyridoxal-4'-fluorophosphate (IPLFP, 6) has been achieved several reaction steps, starting from pyridoxine (PN). The structure was determined by elemental analysis and spectroscopic methods: ¹H NMR, ¹⁹F NMR and UV spectra. The preliminary biological investigation in coenzyme–apoenzyme liganding reactions of aspartate aminotransferase (AST) shows that isopyridoxal-4'-phosphate (IPLP, 5) and its fluorinated derivative IPLFP (6) are well bound at apoenzyme. The catalytic activities of reconstituted AST-IPLP and AST- -IPLFP complexes are much lower (only 10% by IPLFP) in relation to native coenzyme pyridoxal-5'-phosphate (PLP).

Keywords: vitamin B₆, isopyridoxal-4'-phosphate, isopyridoxal-4'-fluorophosphate, dinitrofluorobenzene, Schiff's base, aminotransferase aspartate coenzyme