Californium-252 plasma desorption mass spectrometry as an aid in the synthesis of a series of adenosine and xanthine conjugates

Two series of biologically active purine derivatives have been analyzed using californium-252 plasma desorption mass spectrometry. The series of compounds are adenosine agonists (N6-phenyladenosine derivatives) and antagonists (8-phenyl-1,3-dipropylxanthine derivatives) at extracellular purine receptors. Included are receptor probes synthesized through successive chain elongation reactions. Positive and negative ion spectra are often dominated by signals from the quasimolecular ion [(M+ H)+, (M+ Na)+, (M– H)–] or by peaks resulting from loss of whole molecules such as ribose. The simplicity of sample preparation, spectrometer operation, and interpretation of spectra from the non-heated sample are demonstrated.