Pharmacognosy and medicinal plant raw materials
What the exam tests
This domain tests botanical identity, active constituents, harvesting and drying rules, storage, and quality assessment of medicinal plant raw materials. Kazakhstan’s flora and imported raw materials both appear, including licorice, hawthorn, sea buckthorn, valerian, chamomile, mint, sage, plantain, and thyme.
Core rules
- Identity is confirmed by macroscopic characters, microscopy, and chemical tests or chromatography.
- The active constituent group determines the assay: essential oils, flavonoids, tannins, saponins, alkaloids, or glycosides.
- Collection must occur at the correct phenological stage and from correctly identified plants; poisonous look-alikes are a serious risk.
- Drying temperature depends on the constituent: essential-oil-rich material is dried at lower temperatures to limit loss.
- Store raw materials in dry, dark, ventilated conditions, separated from food and chemicals, and protected from pests and moisture.
Worked example
A supplier offers licorice root. How would you judge identity and quality?
Reasoning: licorice root comes from Glycyrrhiza species. Macroscopically, examine the root for color, fracture, and characteristic sweet taste; microscopically, look for starch grains, fibers, and calcium oxalate. Chemically, glycyrrhizin is the marker. Also check foreign matter, moisture, ash, and microbial contamination. A sweet taste alone is insufficient because other roots may be confused with it; identity must combine botanical and chemical evidence.
Traps that cost marks
- Identifying a plant only by a photograph or local name.
- Collecting essential-oil plants in damp conditions and drying them at high temperature.
- Storing raw materials near disinfectants or pesticides.
- Ignoring foreign matter and microbial limits.
- Assuming that a “natural” product has no contraindications or interactions.
Exam focus
For each raw material, know the plant part, main constituent group, one identity test, and one storage risk.