Introduction: Secondary metabolites are bioactive compounds produced by plants, microbes and marine organisms with wide commercial applications in the pharmaceutical industry, nutraceuticals, agrochemicals, flavors, fragrances and natural pigments. For B.Pharm students, understanding classes like alkaloids, terpenoids, flavonoids and polyketides is essential for drug development, commercialization, bioprocessing and quality control. Topics include examples such as antibiotics, anticancer agents, immunosuppressants and statins, plus production strategies (fermentation, strain improvement), extraction, purification (HPLC, chromatography), biotransformation and regulatory considerations. This focused knowledge links pharmacognosy, pharmaceutics and industrial pharmacy to real-world product development. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which of the following is NOT a typical commercial application of secondary metabolites?
- Pharmaceuticals and antibiotics
- Food additives and nutraceuticals
- Polyester fiber for clothing
- Agrochemicals and biopesticides
Correct Answer: Polyester fiber for clothing
Q2. Which class of secondary metabolites includes morphine, quinine and atropine?
- Alkaloids
- Terpenoids
- Flavonoids
- Polyketides
Correct Answer: Alkaloids
Q3. Lovastatin, an important cholesterol-lowering drug, is commercially produced by which organism group?
- Fungi (Aspergillus species)
- Higher plants
- Marine algae
- Animal tissues
Correct Answer: Fungi (Aspergillus species)
Q4. Which secondary metabolite derived from Taxus species is a key anticancer agent used clinically?
- Paclitaxel
- Vincristine
- Camptothecin
- Etoposide
Correct Answer: Paclitaxel
Q5. Which large-scale production method is most commonly used for industrial microbial secondary metabolite manufacture?
- Submerged fermentation (liquid fermentation)
- Solid-state fermentation only
- Cryoconservation
- Open-air cultivation
Correct Answer: Submerged fermentation (liquid fermentation)
Q6. What is the primary goal of biotransformation in commercial secondary metabolite production?
- Modify natural structures to improve potency, solubility or safety
- Sterilize the fermentation broth
- Sequence the producing organism’s genome
- Increase the color intensity of extracts
Correct Answer: Modify natural structures to improve potency, solubility or safety
Q7. Which chromatographic technique is standard for purification and quality control of secondary metabolites?
- High-performance liquid chromatography (HPLC)
- Gel electrophoresis
- Polymerase chain reaction (PCR)
- X-ray crystallography
Correct Answer: High-performance liquid chromatography (HPLC)
Q8. Which regulatory requirement is most critical for bringing a secondary metabolite-derived drug to market?
- Demonstrating safety and efficacy through clinical trials
- Showing pleasing color and odor
- Securing a retail shelf space
- Registering a social media account
Correct Answer: Demonstrating safety and efficacy through clinical trials
Q9. Which analytical technique is essential for structural elucidation of complex secondary metabolites?
- Nuclear magnetic resonance (NMR) spectroscopy
- ELISA immunoassay
- Gram staining
- Ordinary light microscopy
Correct Answer: Nuclear magnetic resonance (NMR) spectroscopy
Q10. Pyrethrins, used as natural insecticides, belong to which class of secondary metabolites?
- Terpenoids
- Alkaloids
- Glycosides
- Polyketides
Correct Answer: Terpenoids
Q11. Which marketed drug is an example of a secondary metabolite-derived statin?
- Lovastatin
- Aspirin
- Penicillin G
- Metformin
Correct Answer: Lovastatin
Q12. Which microbial secondary metabolite is widely used as an immunosuppressant in organ transplantation?
- Cyclosporine
- Penicillin
- Ibuprofen
- Rifampicin
Correct Answer: Cyclosporine
Q13. Which strain improvement strategy is commonly employed to increase secondary metabolite yields industrially?
- Random mutagenesis and selection of high-producing mutants
- Exposure to sunlight only
- Complete elimination of nutrient salts
- Reducing production temperature to freezing
Correct Answer: Random mutagenesis and selection of high-producing mutants
Q14. Anthocyanins and related pigments with antioxidant activity belong to which class?
- Flavonoids
- Alkaloids
- Terpenoids
- Saponins
Correct Answer: Flavonoids
Q15. What is a major commercial challenge when sourcing secondary metabolites from wild plants?
- Low natural abundance and resource sustainability
- Excessive aqueous solubility
- Too rapid regulatory approval
- Absence of bioactivity
Correct Answer: Low natural abundance and resource sustainability
Q16. Digoxin, a cardiac glycoside used clinically, is obtained from which plant genus?
- Digitalis
- Papaver
- Taxus
- Catharanthus
Correct Answer: Digitalis
Q17. Artemisinin, an effective antimalarial drug, is classified as which type of secondary metabolite?
- Sesquiterpene lactone (terpenoid)
- Macrolide antibiotic
- Aminoglycoside
- Polypeptide toxin
Correct Answer: Sesquiterpene lactone (terpenoid)
Q18. In nutraceuticals, secondary metabolites primarily contribute by:
- Providing specific bioactive health benefits beyond basic nutrition
- Increasing caloric density
- Acting only as coloring agents
- Replacing macronutrients
Correct Answer: Providing specific bioactive health benefits beyond basic nutrition
Q19. Which economic factor most directly influences the commercial viability of a secondary metabolite?
- Production cost and achievable yield at scale
- Number of published papers only
- Color preference of researchers
- Geographic location of discovery alone
Correct Answer: Production cost and achievable yield at scale
Q20. Thin-layer chromatography (TLC) is primarily used in early-stage secondary metabolite work for:
- Rapid profiling and checking presence of metabolites in extracts
- Absolute quantification in finished formulations
- Sequencing biosynthetic genes
- Measuring particle size distribution
Correct Answer: Rapid profiling and checking presence of metabolites in extracts
Q21. Which of the following antibiotics is produced via a polyketide biosynthetic pathway (macrolide)?
- Erythromycin
- Penicillin G
- Streptomycin
- Amoxicillin
Correct Answer: Erythromycin
Q22. Curcumin, a commercially used pigment and studied bioactive, is isolated from which plant and belongs to which class?
- Curcuma longa; polyphenolic diarylheptanoid
- Taxus baccata; diterpenoid
- Digitalis purpurea; cardiac glycoside
- Penicillium chrysogenum; β-lactam
Correct Answer: Curcuma longa; polyphenolic diarylheptanoid
Q23. Which metabolic engineering approach is effective to boost secondary metabolite production in microbes?
- Overexpression of pathway-specific transcription factors and biosynthetic genes
- Complete deletion of all secondary metabolite clusters
- Growing cultures without carbon source
- Eliminating cofactor synthesis entirely
Correct Answer: Overexpression of pathway-specific transcription factors and biosynthetic genes
Q24. Which regulatory document is commonly submitted to authorities for detailed information on a drug substance, including production and quality data?
- Drug Master File (DMF)
- Passport
- Food hygiene certificate
- Marketing brochure
Correct Answer: Drug Master File (DMF)
Q25. Which secondary metabolite class frequently functions in plant defense and has been used as botanical insecticides (e.g., nicotine)?
- Alkaloids
- Flavonoids
- Sugars
- Proteins
Correct Answer: Alkaloids
Q26. In downstream processing of microbial cultures, which step is performed to remove cells and solid debris before extraction?
- Filtration or centrifugation
- Lyophilization of whole broth without separation
- Direct crystallization without clarification
- Genetic modification of cells in the extraction vessel
Correct Answer: Filtration or centrifugation
Q27. Compared to plant sources, what is a major advantage of microbial production of secondary metabolites?
- Easier scale-up, shorter generation time and controlled fermentation
- Requires larger land area and seasonal harvesting
- Produces exactly the same stereochemistry without optimization
- No need for downstream purification
Correct Answer: Easier scale-up, shorter generation time and controlled fermentation
Q28. Vincristine and vinblastine, used in chemotherapy, belong to which group of secondary metabolites?
- Vinca alkaloids (from Catharanthus roseus)
- Anthocyanins
- Essential fatty acids
- Macrolide antibiotics
Correct Answer: Vinca alkaloids (from Catharanthus roseus)
Q29. Which analytical approach is essential to monitor potency and stability of a secondary metabolite in a finished pharmaceutical formulation?
- Stability studies combined with validated HPLC assays
- DNA barcoding of the source organism
- Gram staining
- Behavioral observation only
Correct Answer: Stability studies combined with validated HPLC assays
Q30. What intellectual property strategy best protects commercial exploitation of a novel natural product derivative or production process?
- Filing patents on novel derivatives, formulations and production processes
- Releasing all data immediately into the public domain
- Relying solely on trade names without patents
- Using only trademark registration for the molecule
Correct Answer: Filing patents on novel derivatives, formulations and production processes
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
Mail- Sachin@pharmacyfreak.com