[On the nature of free radicals of adenosine diphosphate in redox system NADH-riboflavin-adenosine diphosphate].

Free radicals formed in redox-system NADH + riboflavin (Rf) containing adenosine diphosphate (ADP) in aqueous solutions at room temperature were investigated by ESR-method. Besides formation during the reaction of semireduced form of ADP heterocycle which is identified by singlet ESR signal arising with halfwidth of about 20 Gs the correlations were shown to appear between intensities of weak low-field and high-field lines, symmetrical relatively field values corresponding to g-factor near 2.00. This was interpreted as the evidence of free radicals formation: PO(3)2-. and free radicals of ADP phosphate fragment.