Section A- The science of medicinal chemistry The medicinal Medicinal chemistry is an interdisciplinary science that, by its very nature, chemist encompasses the sciences of chemistry, biochemistry, physiology, pharma- cology, and molecular modeling, to name but a few. a good understanding of these subject areas is useful, but it is unlikely that any one person could be naster of all. Thus, the pharmaceutical industry relies on multidisciplinary teams of scientists who are specialists in their own fields and can work together structures required. Therefore, the medicinal chemist is an essential member of any drug design team since he or she has to identify whether proposed target structures are likely to be stable and whether they be synthesized or not. Traditionally, the pharmaceutical industry has recruited graduates with a chem- istry degree since this is the best method of acquiring the synthetic organic chemistry skills required for medicinal chemistry. However, it is often the case that graduates with a conventional chemistry degree have little background in the biological sciences and have had to acquire that background on the job. In recent years, many universities have started to offer medicinal chemistry degrees that are specifically designed to prepare chemistry graduates for the pharmaceutical industry. Such degrees contain the important core topics required for a conventional chemistry degree (i.e. physical, inorganic and organic chemistry), but also include topics such as drug design, pharmacology, molecular modeling, combinatorial synthesis, bio-organic and bio-inorganic Drugs are chemicals that are normally of low molecular weight(-100-500)and which interact with macromolecular targets to produce a biological response That biological response may be therapeutically useful in the case of medicines, or harmful in the case of poisons. Most drugs used in medicine are potential isons if taken in doses higher than those recommended Classifications There are several ways in which drugs can be classified. First, drugs can be of drugs classified according to their pharmacological effect- for example, analgesics are drugswhich have a pain-killing effect. This classification is useful for doctors wishing to know the arsenal of drugs available to tackle a particular problem, but it is not satisfactory for a medicinal chemist as there are many different targets and mechanisms by which drugs can have an analgesic effect. Therefore it is not possible to identify a common feature which is shared by all analgesics For example, aspirin and morphine act on different targets and have no struc- tural relationship(Fig. 1). Other examples of drugs that are classified in this way