Decisions occur at key points of the drug discovery process, from hit identification all the way through to IND-enabling studies. Good decisions don't just happen. Often times, they are a result of data points supplied by highly trained and experienced drug discovery chemists.
Natural products are small molecules produced naturally by any organism including primary and secondary metabolites. They include very small molecules, such as urea, and complex structures, such as Taxol. As they may only be isolable in small quantities, have interesting biological activity and chemical structures, natural product synthesis poses an interesting challenge in organic chemistry.