The medicinal chemistry of natural products is interesting in itself, but lessons learned from these compounds, in terms of the relationship between structure and desirable physicochemical properties, is now informing the design of fully synthetic drug candidates against a variety of targets. Furthermore, as more and more non-classical drug targets, such as protein-protein interactions, are pursued in the pharmaceutical industry, macrocyclic molecules are becoming increasingly important as they offer a way to provide drug-protein interactions that cover a larger surface area than...