Goodman and Gilman's The
Pharmacological Basis of Therapeutics
14th Edition
Author(s)Laurence Brunton; Bjorn Knollmann
Print ISBN: 9781264258079
,Question 1
Which development in drug discovery most directly enabled
researchers to move from observing therapeutic effects of crude
medicinal plants toward identifying specific active chemical entities?
A. Replacement of biological assays with clinical trials
B. Isolation and characterization of individual active constituents
,C. Elimination of natural products from drug research
D. Use of adverse-effect monitoring before compound isolation
Correct Answer: B. Isolation and characterization of individual active
constituents
Rationale: Isolating active constituents from medicinal plants allows
investigators to associate a particular chemical compound with a
biological effect and subsequently characterize its pharmacological
properties. A is incorrect because biological assays remain essential for
identifying activity. C is incorrect because natural products continue to
contribute important chemical scaffolds. D is incorrect because adverse-
effect monitoring does not identify the active constituent itself.
Question 2
A researcher identifies a plant extract that consistently reduces
inflammation in experimental models. What should be the most
appropriate next step in a traditional natural-product drug-discovery
process?
A. Administer the extract directly to patients at the highest tolerated
dose
B. Isolate and characterize compounds responsible for the observed
activity
C. Immediately design a commercial dosage form
D. Assume that all compounds in the extract contribute equally to the
effect
Correct Answer: B. Isolate and characterize compounds responsible for
the observed activity
, Rationale: Fractionation, isolation, and chemical characterization can
identify the constituents responsible for biological activity. A bypasses
necessary pharmacological and safety evaluation. C is premature
because the active compound and its properties have not been
established. D is incorrect because extracts may contain numerous
constituents with different or even opposing biological activities.
Question 3
Why can natural products be valuable starting points for drug
discovery?
A. They are inherently free of toxicity
B. They contain chemically diverse molecules that may interact with
biological targets
C. Their pharmacological effects never require structural modification
D. Their active compounds automatically have favorable
pharmacokinetics
Correct Answer: B. They contain chemically diverse molecules that may
interact with biological targets
Rationale: Natural products provide structurally diverse chemical
scaffolds that can reveal biologically active molecules and serve as
starting points for drug development. A is incorrect because natural
compounds can be toxic. C is incorrect because structural optimization
may be necessary. D is incorrect because absorption, distribution,
metabolism, and elimination must still be evaluated.