Early discovery program

As there was no ethnomedicinal history to guide the selection of organisms to probe for bioactive natural products, two basic approaches were taken. Early discovery programs sought to establish... 

B. Early discovery program B. What is the purpose of a DEVELOPMENT IN... 

Once a target has been identified, one can start an early discovery program. In this period, one tries to validate the concept (or the target) in order to decide whether it is worth investing further resources. 

Drug discovery activities can be divided into 3 steps (1) exploratory research (2) early discovery program and (3) mature discovery program. 

Figure 2 illustrates the synthesis of several anthranilic diamides prepared in our early discovery program. Our initial targets consisted of derivatives including those of formula D1-D3. These were prepared by coupling of anthranilamide 2 with substituted benzoyl chlorides 3 in the presence of base. The anthranilamide intermediates 2 could be prepared from isatoic anhydrides by treatment with isopropylamine. 

One early step in the workflow of the medicinal chemist is to computationally search for similar compounds to known actives that are either available in internal inventory or commercially available somewhere in the world, that is, to perform similarity and substructure searches on the worldwide databases of available compounds. It is in the interest of all drug discovery programs to develop a formal process to search for such compounds and place them into the bioassays for both lead generation and analog-based lead optimization. To this end, various similarity search algorithms (both 2D and 3D) should be implemented and delivered directly to the medicinal chemist. These algorithms often prove complementary to each other in terms of the chemical diversity of the resulted compounds [8]. 

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