Medicinal chemistry

Pharmaceutical chemistry" redirects here. For the subject being offered to the GCE A-level students in Singapore, see H3 Pharmaceutical Chemistry.

Medicinal chemistry or pharmaceutical chemistry is a discipline at the intersection of chemistry, pharmacology, and biology involved with designing, synthesizing and developing pharmaceutical drugs. Medicinal chemistry involves the identification, synthesis and development of new chemical entities suitable for therapeutic use. It also includes the study of existing drugs, their biological properties, and their quantitative structure-activity relationships (QSAR). Pharmaceutical chemistry is focused on quality aspects of medicines and aims to assure fitness for the purpose of medicinal products.

Compounds used as medicines are overwhelmingly organic compounds including small organic molecules and biopolymers. However, inorganic compounds and metal-containing compounds have been found to be useful as drugs. For example, the cis-platin series of platinum-containing complexes have found use as anti-cancer agents and Lithium-based medicines have long been useful in treating a wide range of mental illnesses.

Medicinal chemistry is a highly interdisciplinary science combining organic chemistry with biochemistry, computational chemistry, pharmacology, pharmacognosy, molecular biology, statistics, and physical chemistry.

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1 Process of drug discovery
- 1.1 Discovery
- 1.2 Optimization
- 1.3 Development
2 Training in medicinal chemistry
3 See also
4 References
5 External links
- 5.1 Scientific journals

[edit] Process of drug discovery

[edit] Discovery

Discovery is the identification of novel active compounds, often called "hits", which are typically found by screening many compounds (compound library) for the desired biological properties. While a number of approaches toward the identification of hits exist, the most successful of techniques relies on chemical and biological intuition developed through years of rigorous chemical-biological training. Other sources of hits can come from natural sources, such as plants, animals, or fungi. Hits may originate also from synthetic chemical libraries, such as those created through combinatorial chemistry or historic chemical compound collections that are tested en-masse against the biological target in question.

[edit] Optimization

Another step in drug discovery involves further chemical modifications in order to improve the biological and physiochemical properties of a given candidate compound library. Chemical modifications can improve the recognition and binding geometries (pharmacophores) of the candidate compounds, their affinities and pharmacokinetics, or indeed their reactivity and stability toward metabolic degradation. A number of methods have contributed to quantitative metabolic prediction, and a recent example is SPORCalc^[1].The quantitative structure-activity relationship (QSAR) of the pharmacophore play an important part in finding lead compounds, which exhibit the most potency, most selectivity, best pharmacokinetics and least toxicity. QSAR involves mainly physical chemistry and molecular docking tools (CoMFA and CoMSIA), that leads to tabulated data and first and second order equations. There are many theories, the most relevant being Hansch's analysis that involves Hammett electronic parameters, steric parameters and logP(lipophilicity) parameters.

[edit] Development

The final step involves the rendering the lead compounds suitable for use in clinical trials. This involves the optimization of the synthetic route for bulk production, and the preparation of a suitable drug formulation.

[edit] Training in medicinal chemistry

Many workers in the field do not have formal training in medicinal chemistry. Although several graduate schools and Colleges of Pharmacy offer formal Ph.D. programs in medicinal chemistry, frequently the broader education in a chemistry graduate program can provide many of the skills needed. A majority of working medicinal chemists have degrees in organic chemistry, rather than medicinal chemistry.^[2]

Medicinal Chemistry is a multifaceted discipline that encompasses synthetic organic chemistry, natural products chemistry, enzymology, chemical biology, structural biology and computational methods, all of which are aimed at the discovery and development of new therapeutic agents. Medicinal chemistry is by nature an interdisciplinary science, and practitioners have a strong background in organic chemistry, coupled with a broad understanding of biological concepts related to cellular drug targets. Scientists in the field are well positioned to work as part of an interdisciplinary team that uses chemical structural principles to design effective drugs and diagnostic agents. Graduate (Master's and Ph.D.) level programs in medicinal chemistry can be found in traditional medicinal chemistry departments, or in pharmaceutical sciences departments, both of which are traditionally associated with schools of pharmacy. Some chemistry departments also have programs in medicinal chemistry, but students are often not exposed to important biological principles that are necessary for a successful career in drug discovery. Some workers in the field do not have formal training in medicinal chemistry, and receive the necessary biological background after employment. Postdoctoral education of 2–3 years is typical after receiving a Ph.D. in medicinal chemistry. Employment prospects at the Master's level are good in the pharmaceutical industry, and at the Ph.D. level, opportunities for employment in academia, industry or government are available.