Solid-phase synthesis of acridine-peptide conjugates and their analysis by tandem mass spectrometry

[reaction--see text] A novel and high-yielding synthesis of 9-anilinoacridine-4-carboxylic acid is reported. This acid has been used in the solid-phase synthesis of a small combinatorial library of acridine-peptide conjugates. Tandem mass spectrometry (ES-MS/MS) can be used for structure determination of these compounds at a sensitivity of approximately 10 pmol. This work makes possible the generation of acridine-peptide libraries for the discovery of structure-specific nucleic acid ligands via affinity chromatography selection with mass spectrometric detection.