Medicinal Chemistry Lecture Notes PDF

# Medicinal Chemistry ## Medicinal Chemistry Involving biological, medical, Pharmaceutical Sciences. ### Concerned with: - Discovery, design, identification, preparation of drugs - Mode of action (Lead components, prototype) - Structure activity relationships (SAR) - Metabolism ## Drug Biologi...

# Medicinal Chemistry ## Medicinal Chemistry Involving biological, medical, Pharmaceutical Sciences. ### Concerned with: - Discovery, design, identification, preparation of drugs - Mode of action (Lead components, prototype) - Structure activity relationships (SAR) - Metabolism ## Drug Biologically active compound (biological response) used for: - Treating, curing, preventing diseases in humans or animals. - Correcting or modifying physiological functions of the body. ## Classification acc. to origin: | Category | Description | |---|---| | Natural | Obtained from plant/animal. Examples: Vitamins, hormones, antibiotics. | | Synthetic | Complete synthesis of naturally occurring compound. Examples: Atropine, Morphine, Cocaine, Steroids. | | Semi-synthetic | Cannot be purely synthesised. Cannot be isolated from natural source. Example: Semi Synthetic Penicillins. | ## Pharmacological action - No relation between chemical structure and pharmacological activity. ## Pharmacodynamic agent - Various physiological functions of the body. - Example: Antispasmodics, antihypertensives, analgesics, sedatives. ## Medicinal use - Chemotherapeutic agent. - Fight pathogenises. - Examples: Sulphonamides, antibiotics, antiviral, antimalarial, anticancer. ## Nomenclature of drug - **Code designation:** Discover during the early development stages. - **Chemical name:** Describe the chemical structure of the drug. - **Generic/Non proprietary name:** Chosen by official FDA ex Diclofenac. - **Trade/Brand/proprietary name:** By company that manufacture ex voltaren, Catafiam. ## Drug development - **3 Main Ideas:** - Physico-chemical properties (Solubility/ stability/ partition coefficient / ionization) - Drug targets - Drug metabolism (biotransformation) ## Characteristics of the drug and biological effect: - Soluble - Pass various membrane barriers / penetrate the site of action, give action - Excessive distribution - Resist metabolism ## LARME (Liberation, Absorption, Distribution, Metabolism, Excretion) ### Solubility of drug 1. **Appropriate water solubility, acceptable degree of lipid solubility:** | Type | Description | |---|---| | **Hydrogen bonds, water solubility, no intramolecular H-bond** | High intramolecular H bonding, lipid solubility. Hydrophilic | | **Intramolecular H bonding, water solubility, lipid solubility.** | Low intramolecular H bonding, water solubility. Hydrophobic | ### Zwitter ion formation: - Each amino acid carries equal negative (COO-) and positive (NH3+) - Compound is ionizable functional groups. - Water insoluble compound.