Chromium(III) interactions with nucleosides and nucleotides: a mass spectrometric study.

Interactions of [Cr(salprn)(H(2)O)(2)]ClO(4) with nucleosides and dinucleotides were studied using electrospray ionization mass spectrometry. The nucleosides 2'-deoxycytidine, thymidine, 2'-deoxyadenosine, 2'-deoxyguanosine, cytidine, adenosine and guanosine form 1 : 1 and 2 : 1 adducts with [Cr(salprn)](+), whereas the dinucleotides CpG, GpC, ApT, TpA and TpC form only the 1 : 1 adducts. Collisional activation (CA) spectra of these adducts reveal that Cr(+) attaches to the bases in nucleosides and to both the phosphate and base, especially cytosine and guanine moieties, in the nucleotides. The sugar residues appear to offer no binding sites as elimination of sugar residues is fairly abundant in the CA spectra of the adducts of many of the nucleosides. Copyright 1999 John Wiley & Sons, Ltd.