This topic will provide an overview of pharmacognosy, including its definition, historical background, importance in drug discovery, and its relationship with other pharmaceutical sciences.
Introduction to Pharmacognosy
The study of medicines derived from natural sources
| Aspect | Description |
|---|---|
| Pharmacognosy | The scientific discipline that investigates the physical, chemical, biochemical, and biological properties of drugs, drug substances, or potential drug candidates of natural origin (plants, microbes, marine organisms, animals). |
| Key Objectives | • Identify bio‑active compounds • Understand their mechanisms of action • Develop sustainable sourcing and extraction methods • Ensure quality, safety, and efficacy of natural products |
| Related Fields | Phytochemistry, Ethnobotany, Natural Product Chemistry, Pharmacology, Herbal Medicine, Biotechnology |
| Era | Milestones |
|---|---|
| Ancient civilizations (≈3000 BC) | Use of herbs and minerals recorded in Egyptian papyri, Ayurvedic texts, Chinese materia medica. |
| Classical period (500 BC–500 AD) | Dioscorides’ De Materia Medica (1st century) catalogues >600 medicinal plants. |
| Middle Ages | Monastic gardens and Islamic scholars preserve and expand knowledge of medicinal plants. |
| Renaissance & Enlightenment | Development of botanical illustration, Linnaean taxonomy (1735), early isolation of active principles (e.g., morphine, quinine). |
| 19th century | Systematic phytochemical methods; discovery of alkaloids, essential oils, glycosides. |
| 20th century | Rise of synthetic drugs, but renewed interest in natural products for anticancer, antimicrobial, and anti‑inflammatory agents. |
| 21st century | Integration of genomics, metabolomics, and synthetic biology to discover and produce natural compounds. |
| Source | Typical Classes of Compounds | Example Drugs |
|---|---|---|
| Higher plants | Alkaloids, flavonoids, terpenoids, phenolics, glycosides | Vincristine (periwinkle), Aspirin (willow bark), Digoxin (foxglove) |
| Microorganisms (fungi, bacteria) | Antibiotics, immunosuppressants, enzymes | Penicillin (Penicillium), Cyclosporine (Tolypocladium) |
| Marine organisms (sponges, algae, corals) | Halogenated terpenes, peptides, polysaccharides | Trabectedin (sea squirt), Ziconotide (cone snail) |
| Animals | Venoms, peptides, steroids | Captopril (derived from snake venom peptide), Hormones from adrenal glands |
| Synthetic biology/engineered cultures | Recombinant proteins, engineered metabolites | Artemisinin produced in yeast, Taxol in plant cell cultures |
| Step | Common Techniques | Purpose |
|---|---|---|
| Pre‑extraction | Drying, grinding, size reduction | Increase surface area, prevent degradation |
| Extraction | Maceration, Soxhlet, Ultrasound‑assisted, Supercritical CO₂ | Transfer target constituents into a |