Section A- The science of medicinal chemistry A1 INTRODUCTION Key Notes Medicinal chemistry is the design and synthesis of novel drugs, based on an understanding of how they work at the molecular level. A useful drug must interact with a molecular target in the body (pharmacodynamics and also be capable of reaching that target(pharmacokinetics). A medicinal chemist is skilled in the fields of organic synthesis, molecular modeling and drug design, and should have a basic knowledge of relevant subjects such as biochemistry and pharmacology E Drug Drugs are normally low molecular weight chemicals that interact with macromolecular targets in the body to produce a pharmacological effect That effect may be beneficial or harmful depending on the drug used and he dose administered Classifications of Drugs can be classified according to their pharmacological effect, the drugs particular biochemical process they affect, the type of structures they are, or the molecular target with which they interact. The last classification is the most useful one in medicinal chemistry Related topic From concept to market(A2) Medicinal The science of medicinal chemistry involves the design and synthesis of novel drugs based on an understanding of how drugs work in the body at the molec- ular level. There are two major considerations that have to be considered in any drug design project. First of all, drugs interact with molecular targets in the body, and so it is important to choose the correct tar ceutical effect. It is then a case of designing a dne, get for the desired pharma- hat will interact as fully and selectively as possible for that target-an area of medicinal chemistry known as rhan dynamics. Drug targets will be discussed in more detail in Section B. Secondly, a drug has to travel through the body in order to reach its target, so it is important to design the drug so that it is able to carry out that journey. This is an area known as pharmacokinetics and is discussed in Section Medicinal chemistry has come of age in the last 20 years. Before that, advances were often made as a result of trial and error, intuition or pure luck Large numbers of analogs were synthesized based on the structure of a known active compound (defined as the lead compound), but little was known about the detailed mechanism of drug action or the structures of the targets with which they interacted. Advances in the biological sciences have now resulted in a much better understanding of drug targets and the mechanisms of drug action. As a result, drug design is as much"target oriented as 'lead compound