Nature has always been a notable source of bioactive lead compounds and has provided unprecedented opportunities for medicinal chemists to continuously provide drug candidates as new compounds for evaluation. Natural products (NPs) and their derivatives have historically made major contributions to pharmacotherapy, in particular for cancer and infectious diseases. NPs provide intriguing chemical diversity and are considered as being irreplaceable sources of inspiration for new drug discovery and have been validated by their truly enormous contributions in the development of new lead molecules. These secondary metabolites feature diverse chemical structures, and inherently occupy biologically applicable chemical spaces. Notably, NPs and their analogs are responsible for over half of all approved drugs in current use. FDA data illustrated that NPs and their analogs represent more than one-third of all FDA-approved new lead molecules (Li and Lou, 2018).