Medicinal uses of acridine MCQs With Answer

Introduction: The medicinal uses of acridine and its derivatives are essential for B. Pharm students studying pharmacology and medicinal chemistry. Acridine compounds, such as quinacrine, acriflavine, proflavine and amsacrine, show diverse therapeutic roles as antimalarial, antiseptic and anticancer agents. Key pharmacological actions involve DNA intercalation, topoisomerase II inhibition and generation of reactive species, which explain both efficacy and toxicity. Understanding structure–activity relationships, clinical applications, laboratory uses (e.g., acridine orange staining) and safety concerns like mutagenicity and phototoxicity helps in rational drug design and safe use. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the primary molecular mechanism by which many acridine derivatives exert anticancer effects?

• Inhibition of dihydrofolate reductase
• DNA intercalation and topoisomerase II inhibition
• Blocking GABA receptors
• Inhibition of cyclooxygenase

Correct Answer: DNA intercalation and topoisomerase II inhibition

Q2. Which acridine derivative has been historically used as an antimalarial drug?

• Amsacrine
• Quinacrine (Atabrine)
• Acriflavine
• Proflavine

Correct Answer: Quinacrine (Atabrine)

Q3. Amsacrine (m-AMSA) is primarily used in the treatment of which condition?

• Hypertension
• Acute leukemia
• Bacterial pneumonia
• Type 2 diabetes

Correct Answer: Acute leukemia

Q4. Which acridine compound is commonly used as a topical antiseptic and wound disinfectant?

• Quinacrine
• Acriflavine
• Amsacrine
• 9-Aminoacridine

Correct Answer: Acriflavine

Q5. Acridine orange is widely used in laboratories for which purpose?

• Measuring blood glucose
• Fluorescent staining of nucleic acids
• As a general anesthetic
• Anticoagulation of blood samples

Correct Answer: Fluorescent staining of nucleic acids

Q6. Which property of the acridine nucleus makes it suitable for DNA intercalation?

• Highly flexible aliphatic chain
• Planar polycyclic aromatic structure
• Large ionic charge
• High polarity and non-aromaticity

Correct Answer: Planar polycyclic aromatic structure

Q7. Proflavine is primarily known for which clinical application?

• Oral antihyperglycemic
• Topical antiseptic and wound dressing
• Systemic antiviral therapy
• Inhaled bronchodilator

Correct Answer: Topical antiseptic and wound dressing

Q8. Which adverse effect is commonly associated with systemic use of acridine derivatives?

• Hypoglycemia
• Mutagenicity and potential carcinogenicity
• Hyperkalemia
• Increased bone density

Correct Answer: Mutagenicity and potential carcinogenicity

Q9. The 9-position on the acridine ring system is important because substitutions there often affect:

• Renal excretion only
• DNA binding affinity and biological activity
• Color of the compound but not activity
• Melting point exclusively

Correct Answer: DNA binding affinity and biological activity

Q10. Which acridine derivative was historically used as an anti-protozoal for giardiasis and malaria?

• Quinacrine
• Acridine orange
• Amsacrine
• Chloroquine (not acridine)

Correct Answer: Quinacrine

Q11. Which mechanism explains the antimicrobial action of topical acridine antiseptics?

• Enhancing bacterial cell wall synthesis
• DNA intercalation disrupting microbial replication
• Selective blockade of bacterial ribosomes only
• Neutralizing bacterial endotoxins

Correct Answer: DNA intercalation disrupting microbial replication

Q12. Which laboratory safety concern is relevant when handling acridine dyes?

• They are strong acids and cause burns
• Mutagenic and potentially carcinogenic properties
• They produce explosive gas with water
• They rapidly polymerize on exposure to air

Correct Answer: Mutagenic and potentially carcinogenic properties

Q13. Which statement best describes acridine orange fluorescence behavior?

• Emits red fluorescence when bound to DNA and green when bound to RNA
• Emits green fluorescence when bound to DNA and red when bound to RNA
• Does not fluoresce with nucleic acids
• Only fluoresces in presence of proteins

Correct Answer: Emits green fluorescence when bound to DNA and red when bound to RNA

Q14. A key structural feature distinguishing acridine from anthracene is:

• Presence of a nitrogen atom in the central ring
• Lack of aromaticity in acridine
• Higher molecular weight of anthracene
• Acridine has an extra sulfate group

Correct Answer: Presence of a nitrogen atom in the central ring

Q15. Which clinical use is NOT associated with acridine derivatives?

• Topical antisepsis
• Antimalarial therapy
• Anticancer chemotherapy
• Systemic antihypertensive therapy

Correct Answer: Systemic antihypertensive therapy

Q16. The anticancer drug amsacrine intercalates DNA and primarily inhibits which enzyme?

• Acetylcholinesterase
• Topoisomerase II
• DNA polymerase I
• Reverse transcriptase

Correct Answer: Topoisomerase II

Q17. Which acridine derivative is commonly used as a fluorescent probe to assess cell viability and apoptosis?

• Acridine orange
• Quinacrine
• Amsacrine
• Proflavine

Correct Answer: Acridine orange

Q18. SAR studies of acridines show that introducing bulky substituents at specific positions generally affects:

• Only the color but not biological properties
• Membrane permeability and DNA intercalation efficiency
• Only urinary excretion routes
• Ability to bind to opioid receptors

Correct Answer: Membrane permeability and DNA intercalation efficiency

Q19. Which acridine-related adverse effect is particularly relevant for topical use on skin?

• Systemic hypoglycemia
• Phototoxicity and local irritation
• Encephalopathy
• Tendon rupture

Correct Answer: Phototoxicity and local irritation

Q20. Quinacrine’s mechanism in antimalarial action includes interference with:

• Folate synthesis only
• Heme polymerization in Plasmodium food vacuole
• Viral capsid assembly
• Calcium channels in erythrocytes

Correct Answer: Heme polymerization in Plasmodium food vacuole

Q21. Which diagnostic application leverages acridine orange staining?

• Measuring blood pressure
• Counting and differentiating nucleated cells and bacterial cells in microscopy
• Assessing liver enzymes
• Evaluating renal glomerular filtration rate

Correct Answer: Counting and differentiating nucleated cells and bacterial cells in microscopy

Q22. Which of the following is a limitation when developing acridine drugs for systemic use?

• Poor aromaticity
• High mutagenic and genotoxic potential
• Inability to bind DNA
• Complete lack of bioavailability

Correct Answer: High mutagenic and genotoxic potential

Q23. In medicinal chemistry, 9-aminoacridine is notable because it:

• Is a strong opioid agonist
• Is a potent DNA intercalator and proton pump inhibitor
• Has strong intercalative DNA binding and antibacterial activity
• Is used as an antihyperlipidemic agent

Correct Answer: Has strong intercalative DNA binding and antibacterial activity

Q24. Which pharmacokinetic property is a concern for some acridine derivatives used systemically?

• Extensive first-pass metabolism and tissue accumulation
• Complete renal elimination unchanged
• No oral absorption at all
• Rapid metabolism to harmless water

Correct Answer: Extensive first-pass metabolism and tissue accumulation

Q25. Which analytical technique is commonly used to study acridine–DNA interactions?

• GC without derivatization
• UV-Vis spectroscopy and fluorescence titration
• Atomic absorption for metals only
• Polarimetry for sugar analysis

Correct Answer: UV-Vis spectroscopy and fluorescence titration

Q26. Which of the following best describes proflavine’s mode of action as an antimicrobial?

• Disruption of cell membrane lipids exclusively
• DNA intercalation that inhibits replication and transcription
• Selective inhibition of peptidoglycan cross-linking
• Binding to tubulin and inhibiting mitosis

Correct Answer: DNA intercalation that inhibits replication and transcription

Q27. Which clinical concern limits the widespread systemic use of acriflavine?

• Severe hypotension
• Potential mutagenicity and systemic toxicity
• Excessive diuretic effect
• Induction of hyperthyroidism

Correct Answer: Potential mutagenicity and systemic toxicity

Q28. Acridine derivatives that stabilize DNA–drug complexes often cause cell death by triggering:

• Excessive protein synthesis
• DNA strand breaks and apoptosis
• Increased ATP synthesis
• Enhanced fatty acid oxidation

Correct Answer: DNA strand breaks and apoptosis

Q29. Which modification generally increases water solubility of acridine compounds?

• Adding hydrophobic alkyl chains
• Introducing polar substituents (e.g., amino or sulfonate groups)
• Removing nitrogen from the ring
• Increasing planarity of the molecule

Correct Answer: Introducing polar substituents (e.g., amino or sulfonate groups)

Q30. Which acridine derivative has been explored as a candidate for photodynamic therapy due to its photosensitizing properties?

• Proflavine
• Acridine orange
• Quinacrine
• Penicillin

Correct Answer: Acridine orange

Q31. The intercalation of acridine molecules into DNA most directly affects which DNA property?

• Base composition
• Helical twist and replication fork progression
• Number of chromosomes
• Sequence of bases

Correct Answer: Helical twist and replication fork progression

Q32. Which safety precaution is important when disposing of acridine-containing laboratory waste?

• Dump into general sink with soap
• Treat as hazardous chemical waste following mutagenic/carcinogenic protocols
• Autoclave and flush down drain
• Expose to sunlight to neutralize

Correct Answer: Treat as hazardous chemical waste following mutagenic/carcinogenic protocols

Q33. Which clinical feature can result from systemic exposure to certain acridine drugs?

• Skin hyperpigmentation and gastrointestinal disturbances
• Enhanced hair growth only
• Improved vision acuity
• Long-term hypercalcemia exclusively

Correct Answer: Skin hyperpigmentation and gastrointestinal disturbances

Q34. In designing anticancer acridine analogues, medicinal chemists often aim to:

• Reduce DNA affinity entirely
• Optimize intercalation and reduce nonspecific mutagenicity
• Increase nonpolar surface area only
• Eliminate aromaticity

Correct Answer: Optimize intercalation and reduce nonspecific mutagenicity

Q35. Which property of acridine dyes makes them useful for differentiating live and dead cells?

• Their ability to chelate metal ions
• Different fluorescence emission when bound to DNA/RNA or in acidic compartments
• Their enzymatic activity
• Their capacity to inhibit protein synthesis

Correct Answer: Different fluorescence emission when bound to DNA/RNA or in acidic compartments

Q36. Which of the following is TRUE about quinacrine’s modern uses?

• It is commonly used as a first-line systemic antibiotic
• It has niche applications, including antiprion and immunomodulatory research, but limited clinical antimalarial use
• It is an approved treatment for diabetes
• It is exclusively used as a food preservative

Correct Answer: It has niche applications, including antiprion and immunomodulatory research, but limited clinical antimalarial use

Q37. Which test would you use to evaluate DNA strand breaks caused by acridine compounds in experimental cells?

• ELISA for insulin
• Comet assay (single-cell gel electrophoresis)
• Rotarod behavioral test
• Serum creatinine measurement

Correct Answer: Comet assay (single-cell gel electrophoresis)

Q38. Which structural change is often explored to decrease mutagenicity of acridine anticancer agents while retaining activity?

• Increasing planar aromatic surface area
• Incorporating heteroatoms or bulky groups to modulate DNA binding geometry
• Completely removing the nitrogen atom
• Converting to a saturated aliphatic scaffold

Correct Answer: Incorporating heteroatoms or bulky groups to modulate DNA binding geometry

Q39. Which clinical monitoring parameter is important for patients receiving systemic acridine-based chemotherapy?

• Complete blood count for bone marrow suppression
• Daily urine ketones only
• Continuous blood glucose monitoring exclusively
• Audiometry for hearing loss only

Correct Answer: Complete blood count for bone marrow suppression

Q40. Acridine derivatives that disrupt topoisomerase function most directly interfere with:

• Fatty acid metabolism
• DNA replication and segregation
• Membrane ion channels only
• Protein glycosylation

Correct Answer: DNA replication and segregation

Q41. Which of the following best describes acriflavine’s historic use in medicine?

• Systemic antihypertensive agent
• Topical antiseptic and dye with antibacterial properties
• Oral anticoagulant
• Inhaled corticosteroid

Correct Answer: Topical antiseptic and dye with antibacterial properties

Q42. When developing acridine-based anticancer agents, reducing off-target genotoxicity is important because:

• Genotoxicity enhances therapeutic index
• Off-target genotoxicity can cause secondary malignancies and long-term harm
• Genotoxicity has no clinical consequences
• Genotoxicity increases patient compliance

Correct Answer: Off-target genotoxicity can cause secondary malignancies and long-term harm

Q43. Which functional assay can help determine whether an acridine compound causes topoisomerase II-mediated DNA cleavage?

• Topoisomerase II cleavage assay and DNA relaxation assays
• Serum electrolyte panel
• Glucose tolerance test
• Pulse oximetry

Correct Answer: Topoisomerase II cleavage assay and DNA relaxation assays

Q44. Which statement about acridine orange’s cell staining specificity is correct?

• It stains lipids preferentially
• It differentially stains DNA and RNA due to spectral shifts
• It binds only to proteins
• It exclusively stains carbohydrates

Correct Answer: It differentially stains DNA and RNA due to spectral shifts

Q45. Which chemical property of acridines contributes to their ability to cross cell membranes?

• Extremely high polarity and permanent charge
• Amphipathic balance when appropriately substituted
• Total insolubility in lipids
• Large polysaccharide chains

Correct Answer: Amphipathic balance when appropriately substituted

Q46. Which acridine-related compound is used as a biological stain in microbiology to visualize bacteria under fluorescence?

• Acridine orange
• Amsacrine
• Quinidine
• Ibuprofen

Correct Answer: Acridine orange

Q47. Resistance mechanisms to acridine antimicrobials can include:

• Increased drug efflux and decreased uptake
• Complete absence of DNA in bacteria
• Overproduction of insulin
• Enhanced bone mineralization

Correct Answer: Increased drug efflux and decreased uptake

Q48. Which safety statement is true for clinical use of topical acridine agents?

• They are entirely free of local irritation or staining risks
• They may stain tissues and cause local irritation; use with care
• They always cause systemic renal failure
• They are safe for ingestion

Correct Answer: They may stain tissues and cause local irritation; use with care

Q49. In drug design, converting an acridine to a more selective DNA minor groove binder rather than an intercalator aims to:

• Increase nonspecific mutagenicity
• Reduce disruption of DNA helical structure and lower genotoxicity
• Destroy the aromaticity completely
• Prevent any interaction with DNA

Correct Answer: Reduce disruption of DNA helical structure and lower genotoxicity

Q50. Which factor is critical when assessing new acridine analogues for clinical development?

• Only the color and odor
• Balance of potency, selectivity, pharmacokinetics and safety (mutagenicity/toxicity)
• Ability to form crystals for packaging only
• Capacity to ferment in microbial cultures

Correct Answer: Balance of potency, selectivity, pharmacokinetics and safety (mutagenicity/toxicity)

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