Phenyl radicals react with dinucleoside phosphates by addition to purine bases and H-atom abstraction from a sugar moiety.

Laser-induced acoustic desorption combined with mass spectrometry has been used to demonstrate that phenyl radicals can attack dinucleoside phosphates at both the sugar and base moieties, that purine bases are more susceptible to the attack than pyrimidine bases, and that the more electrophilic the radical, the more efficient the damage to dinucleoside phosphates.

Reactivity of substituted charged phenyl radicals toward components of nucleic acids.

Reactions of differently substituted phenyl radicals with components of nucleic acids have been investigated in the gas phase. A positively charged group located meta with respect to the radical site was employed to allow manipulation of the radicals in a Fourier-transform ion cyclotron resonance mass spectrometer. All of these electrophilic radicals react with sugars via exclusive hydrogen atom abstraction, with adenine and uracil almost exclusively via addition (likely at the C8 and C5 carbons, respectively), and with the nucleoside thymidine by hydrogen atom abstraction and addition at C5 in the base moiety (followed by elimination of (*)CH(3)).

Gas-phase reactions of charged phenyl radicals with neutral biomolecules evaporated by laser-induced acoustic desorption.

A generally applicable method for the study of phenyl radicals' reactions with neutral biomolecules in the gas phase is demonstrated. Neutral biomolecules were evaporated into a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR) by means of laser-induced acoustic desorption (LIAD) and subsequently reacted with trapped charged phenyl radicals. The structural integrity of the evaporated alanylalanine molecules was verified by reaction with dichlorophosphenium ions.