As could be expected, the first ranks in both charts are dominated by single-ring scaffolds, since they represent the final stage of scaffold dissection and have the most origin molecules, therefore. The first ranks are also dominated by 6-membered rings and parent scaffolds that are most likely resulting from the dissection of polyketides. The frequency of oxygencontaining scaffolds is higher than that of nitrogen, as can be expected for NP. The empty cells in both charts represent empty scaffolds, i.e. scaffolds of molecules that have no rings.