,
,Question 1
A research team identifies an extract from a medicinal plant that
reduces inflammation in a laboratory assay. The investigators want to
determine whether the extract contains a compound that could serve
as the starting point for developing a therapeutic drug. Which step is
most appropriate next?
A. Begin routine clinical use of the extract in patients with inflammatory
disorders.
B. Conduct bioassay-guided fractionation to isolate and identify the
constituent or constituents associated with the observed activity.
C. Assume that the extract is safe because it originates from a natural
source.
D. Proceed directly to large-scale manufacturing without further
chemical characterization.
Correct Answer: B. Conduct bioassay-guided fractionation to isolate and
identify the constituent or constituents associated with the observed
activity.
Rationale:
• A is incorrect: Activity in a laboratory assay does not establish
safety, efficacy, appropriate dosing, or clinical benefit in humans.
Additional characterization and preclinical evaluation are
necessary.
• B is correct: Bioassay-guided fractionation combines biological
testing with successive separation of an extract. By testing
individual fractions, investigators can identify which components
, contribute to the desired pharmacological activity and
subsequently characterize promising compounds.
• C is incorrect: Natural origin does not guarantee safety. Plant-
derived substances can cause toxicity, interact with medications,
or have narrow therapeutic windows.
• D is incorrect: Large-scale production before identifying the active
constituent and understanding its properties could waste
resources and produce material with inconsistent composition or
activity.
Question 2
A pharmacologist separates a biologically active plant extract into
several fractions. The original extract inhibits a disease-associated
enzyme, but only two fractions retain substantial inhibitory activity.
What is the principal purpose of repeatedly separating and testing
these fractions?
A. To eliminate the need for identifying the chemical structures of active
compounds.
B. To demonstrate that every constituent of the original extract
contributes equally to the biological effect.
C. To determine the maximum tolerated dose of the extract in humans.
D. To progressively concentrate and identify the chemical constituents
responsible for the measured biological activity.
Correct Answer: D. To progressively concentrate and identify the
chemical constituents responsible for the measured biological activity.
Rationale:
,Question 1
A research team identifies an extract from a medicinal plant that
reduces inflammation in a laboratory assay. The investigators want to
determine whether the extract contains a compound that could serve
as the starting point for developing a therapeutic drug. Which step is
most appropriate next?
A. Begin routine clinical use of the extract in patients with inflammatory
disorders.
B. Conduct bioassay-guided fractionation to isolate and identify the
constituent or constituents associated with the observed activity.
C. Assume that the extract is safe because it originates from a natural
source.
D. Proceed directly to large-scale manufacturing without further
chemical characterization.
Correct Answer: B. Conduct bioassay-guided fractionation to isolate and
identify the constituent or constituents associated with the observed
activity.
Rationale:
• A is incorrect: Activity in a laboratory assay does not establish
safety, efficacy, appropriate dosing, or clinical benefit in humans.
Additional characterization and preclinical evaluation are
necessary.
• B is correct: Bioassay-guided fractionation combines biological
testing with successive separation of an extract. By testing
individual fractions, investigators can identify which components
, contribute to the desired pharmacological activity and
subsequently characterize promising compounds.
• C is incorrect: Natural origin does not guarantee safety. Plant-
derived substances can cause toxicity, interact with medications,
or have narrow therapeutic windows.
• D is incorrect: Large-scale production before identifying the active
constituent and understanding its properties could waste
resources and produce material with inconsistent composition or
activity.
Question 2
A pharmacologist separates a biologically active plant extract into
several fractions. The original extract inhibits a disease-associated
enzyme, but only two fractions retain substantial inhibitory activity.
What is the principal purpose of repeatedly separating and testing
these fractions?
A. To eliminate the need for identifying the chemical structures of active
compounds.
B. To demonstrate that every constituent of the original extract
contributes equally to the biological effect.
C. To determine the maximum tolerated dose of the extract in humans.
D. To progressively concentrate and identify the chemical constituents
responsible for the measured biological activity.
Correct Answer: D. To progressively concentrate and identify the
chemical constituents responsible for the measured biological activity.
Rationale:
