TEST BANK
Goodman and Gilman's The
Pharmacological Basis of Therapeutics
14th Edition
Author(s)Laurence Brunton; Bjorn Knollmann
Print ISBN: 9781264258079
,Question 1
A researcher is investigating a medicinal plant traditionally used to
relieve inflammatory symptoms. An extract shows activity in an initial
laboratory assay. Which next step would best help identify the
substance responsible for the observed activity?
A. Begin clinical trials using the crude extract
B. Perform bioassay-guided fractionation of the extract
C. Increase the extraction temperature until all compounds are
removed
,D. Select the most abundant compound regardless of biological
activity
Correct Answer: B. Perform bioassay-guided fractionation of the
extract
Rationale:
Bioassay-guided fractionation repeatedly separates an active extract
into fractions and tests those fractions for activity, allowing
investigators to track the biologically active constituent. This links
chemical separation directly to biological effect.
• A is incorrect: Clinical testing requires substantially more
evidence regarding the active substance, efficacy, safety,
formulation, and exposure.
• C is incorrect: Increasing extraction temperature does not
establish which constituent produces the biological effect and
may degrade thermolabile compounds.
• D is incorrect: The most abundant compound is not necessarily
the biologically active compound.
Question 2
A natural-product researcher isolates a single compound from a plant
extract and confirms that the purified compound reproduces the
extract's original biological activity. What is the primary significance of
this finding?
A. The compound has automatically been shown to be clinically
effective
, B. The compound can be considered a candidate for further lead
optimization
C. The compound must be the safest constituent of the original extract
D. The compound no longer requires structural characterization
Correct Answer: B. The compound can be considered a candidate for
further lead optimization
Rationale:
A purified active compound provides a defined chemical entity that
can be studied for potency, selectivity, mechanism, pharmacokinetics,
toxicity, and opportunities for structural optimization. It may
therefore become a lead or provide a starting point for lead discovery.
• A is incorrect: Activity in an experimental assay does not
establish clinical efficacy.
• C is incorrect: Biological activity does not imply safety.
• D is incorrect: Structural characterization is essential for
identifying the compound and enabling rational chemical
development.
Question 3
Which characteristic most strongly distinguishes a lead compound
from an initial screening hit?
A. A lead has already been approved for therapeutic use
B. A lead has sufficient promise to undergo systematic optimization
C. A lead must always be derived from a medicinal plant
Goodman and Gilman's The
Pharmacological Basis of Therapeutics
14th Edition
Author(s)Laurence Brunton; Bjorn Knollmann
Print ISBN: 9781264258079
,Question 1
A researcher is investigating a medicinal plant traditionally used to
relieve inflammatory symptoms. An extract shows activity in an initial
laboratory assay. Which next step would best help identify the
substance responsible for the observed activity?
A. Begin clinical trials using the crude extract
B. Perform bioassay-guided fractionation of the extract
C. Increase the extraction temperature until all compounds are
removed
,D. Select the most abundant compound regardless of biological
activity
Correct Answer: B. Perform bioassay-guided fractionation of the
extract
Rationale:
Bioassay-guided fractionation repeatedly separates an active extract
into fractions and tests those fractions for activity, allowing
investigators to track the biologically active constituent. This links
chemical separation directly to biological effect.
• A is incorrect: Clinical testing requires substantially more
evidence regarding the active substance, efficacy, safety,
formulation, and exposure.
• C is incorrect: Increasing extraction temperature does not
establish which constituent produces the biological effect and
may degrade thermolabile compounds.
• D is incorrect: The most abundant compound is not necessarily
the biologically active compound.
Question 2
A natural-product researcher isolates a single compound from a plant
extract and confirms that the purified compound reproduces the
extract's original biological activity. What is the primary significance of
this finding?
A. The compound has automatically been shown to be clinically
effective
, B. The compound can be considered a candidate for further lead
optimization
C. The compound must be the safest constituent of the original extract
D. The compound no longer requires structural characterization
Correct Answer: B. The compound can be considered a candidate for
further lead optimization
Rationale:
A purified active compound provides a defined chemical entity that
can be studied for potency, selectivity, mechanism, pharmacokinetics,
toxicity, and opportunities for structural optimization. It may
therefore become a lead or provide a starting point for lead discovery.
• A is incorrect: Activity in an experimental assay does not
establish clinical efficacy.
• C is incorrect: Biological activity does not imply safety.
• D is incorrect: Structural characterization is essential for
identifying the compound and enabling rational chemical
development.
Question 3
Which characteristic most strongly distinguishes a lead compound
from an initial screening hit?
A. A lead has already been approved for therapeutic use
B. A lead has sufficient promise to undergo systematic optimization
C. A lead must always be derived from a medicinal plant
