MPharm Master of Pharmacy Pharmacognosy and Natural Products 1 — Questions and Answers
Question 1: Which class of secondary metabolites includes morphine, quinine, and vincristine?
- Terpenoids
- Alkaloids (Correct answer)
- Flavonoids
- Glycosides
Correct answer: Alkaloids
Alkaloids are nitrogen-containing secondary metabolites derived from amino acids and include many pharmacologically significant compounds like morphine and quinine.
Question 2: What is the pharmacologically active component of the foxglove plant (Digitalis purpurea) used in cardiac therapy?
- Atropine
- Digoxin and digitoxin (cardiac glycosides) (Correct answer)
- Quinine
- Reserpine
Correct answer: Digoxin and digitoxin (cardiac glycosides)
Digitalis contains cardiac glycosides (digoxin, digitoxin) that inhibit Na+/K+ ATPase, increasing cardiac contractility used in heart failure treatment.
Question 3: Which extraction technique is most commonly used to isolate essential oils from plant material in pharmacognosy?
- Soxhlet extraction
- Steam distillation (Correct answer)
- Cold maceration
- Ultrasound-assisted extraction
Correct answer: Steam distillation
Steam distillation is the classical method for isolating volatile essential oils; steam carries the volatiles, which are then condensed and separated.
Question 4: Artemisinin, the antimalarial compound derived from Artemisia annua, belongs to which chemical class?
- Alkaloid
- Sesquiterpene lactone endoperoxide (Correct answer)
- Flavonoid glycoside
- Triterpene saponin
Correct answer: Sesquiterpene lactone endoperoxide
Artemisinin is a sesquiterpene lactone containing a unique 1,2,4-trioxane endoperoxide bridge essential for its antimalarial activity.
Question 5: Which test is used to detect the presence of tannins in plant extracts?
- Molisch's test
- Ferric chloride test (Correct answer)
- Biuret test
- Benedict's test
Correct answer: Ferric chloride test
Tannins form blue-black or green complexes with ferric chloride (FeCl₃) due to their phenolic hydroxyl groups chelating iron.
Question 6: Which plant is the natural source of taxol (paclitaxel), an important anticancer agent?
- Vinca rosea
- Taxus brevifolia (Pacific yew) (Correct answer)
- Catharanthus roseus
- Podophyllum peltatum
Correct answer: Taxus brevifolia (Pacific yew)
Paclitaxel was originally isolated from the bark of Taxus brevifolia (Pacific yew) and works by stabilizing microtubules to prevent cell division.
MPharm Master of Pharmacy Pharmacognosy and Natural Products 1
Which class of secondary metabolites includes morphine, quinine, and vincristine?