Chemical Modeling: From Paul Ehrlich's Dyes to β-Blockers - A Brief History

The synthesis on the laboratory bench of the natural product known as alizarin was achieved in 1868. The subsequent elucidation of its structure was a milestone in the development of chemical theory based on Kekulé's benzene ring and in the growth of the synthetic dyestuff industry. Dye and dyeing properties and theories were exploited for biological studies by the medical researcher Paul Ehrlich. Particular attention was paid to the side chains (functional or attached groups of atoms) of molecules. They became important in visualizing a mechanism for immunity, and then in the early 1900s for enabling a description of chemotherapeutic action. These side chains were transformed into the receptors that played a vital role in the development of theories well suited to the design of drugs during the second half of the twentieth century.