Goodman and Gilman's The
Pharmacological Basis of Therapeutics
14th Edition
Author(s)Laurence Brunton; Bjorn Knollmann
Print ISBN: 9781264258079
,Question 1
A research group investigating a medicinal plant observes that a crude
extract produces a reproducible biological effect in an animal model.
Which feature of this discovery approach best distinguishes it from a
target-driven computer-aided strategy?
A. The biologic effect is identified before the molecular target is
necessarily known
,B. The compound must first be docked into a crystallographically
defined receptor
C. A virtual library is screened before any biological testing occurs
D. The mechanism of action must be established before activity is
recognized
Correct Answer: A
Rationale:
A is correct because traditional natural-product discovery can begin
with an observed biological effect from a plant extract without prior
knowledge of the molecular target. This illustrates the historical
progression from empiric observations toward increasingly target- and
structure-informed discovery approaches, including computer-aided
drug design.
B is incorrect because molecular docking is characteristic of
computational approaches and is not required for initial recognition of
activity in a natural product.
C is incorrect because virtual screening is a computational strategy
rather than a defining feature of empirical natural-product discovery.
D is incorrect because the initial effect may be recognized before its
mechanism is understood.
Question 2
A medicinal chemist isolates an active constituent from a plant extract
and finds that the purified compound produces a more reproducible
pharmacological effect than the crude extract. What is the primary
value of isolating the active constituent?
, A. It eliminates the need for further pharmacological testing
B. It identifies a defined chemical entity that can be characterized and
optimized
C. It guarantees that the compound will be clinically effective
D. It demonstrates that the original plant contains only one biologically
active molecule
Correct Answer: B
Rationale:
B is correct because isolating a defined active molecule permits
characterization of its chemical structure, biological activity, and
potential for chemical optimization.
A is incorrect because isolation does not eliminate the need for
pharmacological, toxicological, and developmental testing.
C is incorrect because biological activity does not establish clinical
efficacy.
D is incorrect because a plant may contain multiple active constituents,
including compounds with additive, synergistic, or opposing effects.
Question 3
A screening program identifies thousands of compounds that interact
with a disease-associated molecular target. The investigators now need
to determine which compounds are worth developing further. Which
property is most important at this stage?
A. The compound has activity only at extremely high concentrations
B. The compound produces the desired activity together with
unacceptable nonspecific toxicity