Goodman and Gilman's The
Pharmacological Basis of Therapeutics
14th Edition
Author(s)Laurence Brunton; Bjorn Knollmann
Print ISBN: 9781264258079
,Question 1
Which observation best illustrates the historical role of medicinal plants
in early drug discovery?
A. A synthetic compound is optimized using molecular docking before
any biological testing
B. A plant extract produces a reproducible physiological effect,
prompting isolation of its active constituent
,C. A computer algorithm predicts a receptor-binding molecule from a
protein structure
D. A randomized clinical trial identifies a previously unknown chemical
entity
Correct Answer:
B. A plant extract produces a reproducible physiological effect,
prompting isolation of its active constituent
Rationale:
B is correct because early drug discovery often began with empirical
observations that plants or plant preparations produced useful
biological effects, followed by isolation and characterization of active
compounds. This approach preceded modern target-based and
computer-assisted discovery.
A is incorrect because molecular docking represents a modern
computational approach rather than the historical plant-based
approach.
C is incorrect because structure-guided prediction depends on
contemporary knowledge of molecular targets and computational
methods.
D is incorrect because clinical trials generally occur after a candidate
drug has already been identified and developed.
Question 2
A researcher obtains a crude extract from a medicinal plant and
observes antibacterial activity. What is the most appropriate next step
when attempting to identify the responsible compound?
, A. Immediately begin phase 3 clinical testing
B. Purify fractions of the extract while monitoring antibacterial activity
C. Discard the extract because it contains multiple compounds
D. Convert the entire extract into a synthetic combinatorial library
Correct Answer:
B. Purify fractions of the extract while monitoring antibacterial activity
Rationale:
B is correct because activity-guided fractionation can progressively
separate a complex natural mixture while allowing investigators to
determine which fraction retains the desired biological activity.
A is incorrect because a crude plant extract is not ready for advanced
clinical testing.
C is incorrect because mixtures can contain valuable pharmacologically
active molecules that can be isolated and characterized.
D is incorrect because converting a crude extract into a combinatorial
library is not the logical first step in identifying its active constituent.
Question 3
A natural product is found to have strong activity against a disease-
associated biological process, but its precise molecular structure is
initially unknown. Why is structural characterization important for
further drug discovery?
A. It eliminates the need for biological testing
B. It allows researchers to determine which molecular features can be
modified during optimization