CHARACTERIZATION OF THE COMPLEXITY OF SMALL-MOLECULE LIBRARIES BY ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY

The growing interest in combinatorial chemistry has led us to explore new analytical methods for the analysis of complex molecular libraries . Because an investigation of large mixtures with 10(4)-10(5) differen t chemical entities was not realistic, an alternative approach was pur sued that included the analysis of small representative sublibraries u sing positive and negative ion electrospray mass spectrometry. The det ailed analysis of these model mixtures, containing up to 55 components , allowed us to obtain important information about the composition of a library with considerable complexity. The results were used to impro ve the synthetic procedure in order to provide the maximum yield of ex pected library components. The applicability of mass spectrometry to t he analysis of complex matrices and the usefulness of the technique fo r screening synthesized combinatorial libraries to probe their expecte d diversity and complexity have been demonstrated.