In this analysis, the drugs were
classified as N (an unmodified natural product); ND (a
modified natural product); S (a synthetic compound with no
natural product conception); S/NM (a synthetic compound
showing competitive inhibition of the natural product
substrate); S* (a synthetic compound with a natural product
pharmacophore); and S*/NM (a synthetic compound with a
natural product pharmacophore showing competitive inhibition
of the natural product substrate).