In the field of drug discovery, target structures are often unavailable, but some small molecules may be known to regulate targets. In this case, small molecules are used as the basis for discovery. Ligand-based drug discovery (LBDD) refers to the discovery of drugs in the absence of any target structure and the presence of a chemical structure that can regulate the target. Ligand-based drug discovery starts with a single peptide compound or a group of peptide compounds known to be effective for the target, and based on the understanding of the structure-activity relationship (SAR), through the design of appropriate analogs to improve potency and other important properties. ligand drug discovery https://www.pepdd.com/services..../ligand-based-drug-d