Molecule of the Month
May 2005
The Small Molecule Chemical Universe

The development of modern medicine largely depends on the continuous discovery of new drug molecules for treating diseases. Drug discovery focuses on small building blocks with MW of 160 daltons or less. How many such very small molecules are possible in total within the boundaries of synthetic organic chemistry? To address this question we have generated a database (GDB) containing all possible organic structures with up to 11 main atoms under constraints defining chemical stability and synthetic feasibility. The database contains 13.9 million molecules with an average MW of 153 daltons, and opens an unprecedented window on the small molecule chemical universe.

This work was carried out in the group of Prof. Jean-Louis Reymond.


  • T. Fink, H. Bruggesser, J.-L. Reymond;
    "Virtual Exploration of the Small-Molecule Chemical Universe below 160 Daltons"
    Angew. Chem. Int. Ed., 44, 1504-1508, (2005); doi:10.1002/anie.200462457.