Resins – Podophyllotoxin MCQs With Answer

Resins – Podophyllotoxin MCQs With Answer

Podophyllotoxin is a biologically active lignan resin obtained from Podophyllum species and related plants. This natural product and its semisynthetic derivatives (etoposide, teniposide) are important in pharmacology and anticancer therapy. B. Pharm students should master its extraction, chemistry, stereochemistry, mechanism (microtubule inhibition vs. topoisomerase II inhibition for derivatives), topical antiviral use for warts, systemic toxicity, formulation, and analytical assays (HPLC). Key terms: Resins, Podophyllotoxin, lignan, Podophyllum, extraction, HPLC assay, etoposide, teniposide, mechanism, topical therapy. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What class of natural products does podophyllotoxin belong to?

  • Lignan
  • Alkaloid
  • Terpenoid
  • Flavonoid

Correct Answer: Lignan

Q2. Which plant is a major natural source of podophyllotoxin?

  • Podophyllum peltatum (mayapple)
  • Digitalis purpurea
  • Taxus baccata
  • Camellia sinensis

Correct Answer: Podophyllum peltatum (mayapple)

Q3. The primary cellular mechanism of action of podophyllotoxin is:

  • Inhibition of microtubule assembly by binding tubulin
  • Inhibition of topoisomerase II-DNA complex
  • Alkylation of DNA bases
  • Inhibition of dihydrofolate reductase

Correct Answer: Inhibition of microtubule assembly by binding tubulin

Q4. Which semisynthetic derivative of podophyllotoxin is widely used as an anticancer drug inhibiting topoisomerase II?

  • Etoposide
  • Vincristine
  • Cisplatin
  • Paclitaxel

Correct Answer: Etoposide

Q5. Topical podophyllotoxin formulations are primarily used for which condition?

  • Genital warts (condylomata acuminata)
  • Psoriasis
  • Acne vulgaris
  • Eczema

Correct Answer: Genital warts (condylomata acuminata)

Q6. Major systemic toxicity associated with podophyllotoxin derivatives like etoposide is:

  • Bone marrow suppression (myelosuppression)
  • Renal tubular necrosis
  • Pulmonary fibrosis as primary toxicity
  • Severe hypoglycemia

Correct Answer: Bone marrow suppression (myelosuppression)

Q7. Podophyllotoxin is best described structurally as which type of lignan?

  • Aryltetralin lignan
  • Dibenzylbutane lignan
  • Seco-isolariciresinol lignan

Correct Answer: Aryltetralin lignan

Q8. Which functional group is characteristic on the aromatic ring of podophyllotoxin and contributes to activity?

  • Methylenedioxy moiety
  • Nitro group
  • Sulfhydryl group
  • Primary amine

Correct Answer: Methylenedioxy moiety

Q9. The water solubility profile of podophyllotoxin is:

  • Poorly soluble in water, soluble in organic solvents
  • Highly soluble in water
  • Instantly soluble in saline
  • Only soluble in strong acids

Correct Answer: Poorly soluble in water, soluble in organic solvents

Q10. Which solvent is commonly used for extraction of podophyllotoxin from plant material in the laboratory?

  • Methanol
  • Water
  • Petroleum ether (nonpolar only)
  • Liquid ammonia

Correct Answer: Methanol

Q11. The preferred analytical technique for quantitative determination of podophyllotoxin in extracts and formulations is:

  • High-performance liquid chromatography (HPLC)
  • Thin-layer chromatography (TLC) qualitative only
  • Paper chromatography
  • Gel electrophoresis

Correct Answer: High-performance liquid chromatography (HPLC)

Q12. Lignan biosynthesis, including podophyllotoxin, is primarily derived from which metabolic pathway?

  • Phenylpropanoid pathway (from phenylalanine)
  • Mevalonate pathway
  • Polyketide pathway
  • Urea cycle

Correct Answer: Phenylpropanoid pathway (from phenylalanine)

Q13. Etoposide’s cytotoxic mechanism is best described as:

  • Stabilization of topoisomerase II–DNA cleavable complex leading to DNA breaks
  • Direct crosslinking of DNA strands
  • Inhibition of microtubule polymerization
  • Inhibition of thymidylate synthase

Correct Answer: Stabilization of topoisomerase II–DNA cleavable complex leading to DNA breaks

Q14. Commercial topical podophyllotoxin preparations (e.g., Podofilox) are typically formulated at which concentration?

  • 0.5% solution/gel
  • 5% cream
  • 10% ointment
  • 0.01% lotion

Correct Answer: 0.5% solution/gel

Q15. The primary cellular outcome of podophyllotoxin action on infected epithelial cells when applied topically is:

  • Mitotic arrest and localized cytotoxic necrosis of wart tissue
  • Systemic immunosuppression
  • Stimulation of collagen synthesis
  • Inhibition of keratinocyte differentiation only

Correct Answer: Mitotic arrest and localized cytotoxic necrosis of wart tissue

Q16. Podophyllotoxin and many of its derivatives are sensitive to which environmental factors affecting stability?

  • Light and heat (photolabile and thermolabile)
  • Completely stable under all conditions
  • Only sensitive to strong magnetic fields
  • Stable to UV but unstable to oxygen-free environments

Correct Answer: Light and heat (photolabile and thermolabile)

Q17. Which of the following derivatives is more lipophilic and often used in pediatric oncology?

  • Teniposide
  • Etoposide phosphate
  • Podophyllotoxin topical
  • Vinblastine

Correct Answer: Teniposide

Q18. Podophyllotoxin arrests cells in which phase of the cell cycle?

  • M phase (metaphase) due to microtubule inhibition
  • G1 phase only
  • S phase by inhibiting DNA synthesis directly
  • G2 phase exclusively

Correct Answer: M phase (metaphase) due to microtubule inhibition

Q19. Which metabolic enzyme is primarily involved in hepatic metabolism of etoposide?

  • CYP3A4
  • Monoamine oxidase
  • Alcohol dehydrogenase
  • Acetylcholinesterase

Correct Answer: CYP3A4

Q20. Which formulation strategy is commonly used to improve solubility and bioavailability of semisynthetic podophyllotoxin derivatives?

  • Prodrug formation or water-soluble salts (e.g., etoposide phosphate)
  • Mixing with heavy metals
  • Dry inhalation powders only
  • Adding table salt to the formulation

Correct Answer: Prodrug formation or water-soluble salts (e.g., etoposide phosphate)

Q21. During quality control of a podophyllotoxin topical product, a stability-indicating assay should detect:

  • Podophyllotoxin and its degradation products
  • Only the vehicle components
  • Only microbial contaminants
  • Only color changes

Correct Answer: Podophyllotoxin and its degradation products

Q22. Which laboratory extraction technique enhances yield of podophyllotoxin from dried rhizomes by continuous solvent percolation?

  • Soxhlet extraction
  • Cold maceration only
  • Steam distillation
  • Supercritical CO2 without solvent modifiers

Correct Answer: Soxhlet extraction

Q23. Which statement about podophyllotoxin’s oral use is correct?

  • Unmodified podophyllotoxin is not used systemically because of severe toxicity
  • Podophyllotoxin is routinely given orally for skin warts
  • It is the preferred oral antiviral for influenza
  • Systemic podophyllotoxin is safe in pregnancy

Correct Answer: Unmodified podophyllotoxin is not used systemically because of severe toxicity

Q24. In structure–activity relationships of podophyllotoxin derivatives, modification at which position commonly produces topoisomerase II inhibitors like etoposide?

  • Modification of the C-4 position to introduce glycosidic/side chains
  • Removal of all aromatic rings
  • Substitution with long polyether chains at the lactone carbonyl
  • Hydrogenation of all double bonds only

Correct Answer: Modification of the C-4 position to introduce glycosidic/side chains

Q25. Which adverse effect is relatively uncommon with etoposide compared to many other cytotoxics?

  • Cardiotoxicity
  • Alopecia
  • Nausea and vomiting

Correct Answer: Cardiotoxicity

Q26. Which safety consideration is essential when handling podophyllotoxin in the lab or pharmacy?

  • Use gloves and protective measures due to its cytotoxicity and potential for systemic absorption
  • No special precautions are needed; it is nonhazardous
  • Only eye protection is required; skin contact is harmless
  • It must be handled under inert gas only

Correct Answer: Use gloves and protective measures due to its cytotoxicity and potential for systemic absorption

Q27. Which chromatographic detector is commonly paired with HPLC for sensitive quantitation of podophyllotoxin?

  • UV-visible detector (photodiode array)
  • Conductivity detector
  • Flame ionization detector (FID)
  • Refractive index detector only

Correct Answer: UV-visible detector (photodiode array)

Q28. Teniposide differs from etoposide mainly by which structural change?

  • A thienyl group replacing a substituent, increasing lipophilicity
  • Complete removal of the lactone ring
  • Conversion to a peptide conjugate
  • Attachment of a radioactive isotope

Correct Answer: A thienyl group replacing a substituent, increasing lipophilicity

Q29. Which factor most influences the harvesting time of Podophyllum plants for optimal podophyllotoxin yield?

  • Plant part and season (rhizome maturity and seasonality)
  • Altitude only
  • Color of flowers exclusively
  • Soil pH only

Correct Answer: Plant part and season (rhizome maturity and seasonality)

Q30. For a B. Pharm student preparing formulations, which regulatory consideration is critical for podophyllotoxin topical products?

  • Demonstration of content uniformity, stability, and safety (local irritation and systemic absorption studies)
  • Only color and fragrance specifications are required
  • Generic copying without stability data is acceptable
  • No antimicrobial preservation testing is needed

Correct Answer: Demonstration of content uniformity, stability, and safety (local irritation and systemic absorption studies)

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