Goodman and Gilman's The
Pharmacological Basis of Therapeutics
14th Edition
Author(s)Laurence Brunton; Bjorn Knollmann
Print ISBN: 9781264258079
,Question 1
A research team identifies a plant traditionally used to relieve fever and
decides to investigate it as a potential source of a new therapeutic
agent. Which step is most appropriate early in the drug-discovery
process?
A. Administer the whole plant preparation to patients in a phase III trial
B. Isolate and characterize potentially active chemical constituents
,C. Begin large-scale manufacturing of the plant extract
D. Determine the drug's postmarketing adverse-event profile
Correct Answer: B. Isolate and characterize potentially active chemical
constituents
Rationale:
B is correct because medicinal plants can serve as sources of bioactive
compounds, but the active constituents must be identified and
characterized before systematic development. A is inappropriate
because clinical trials require adequate preclinical characterization and
safety information. C is premature before an active candidate has been
established. D occurs after a drug has reached clinical use and therefore
is not an early discovery step.
Question 2
Which characteristic makes a natural product particularly valuable as a
starting point for drug discovery?
A. It is automatically safe in humans
B. It necessarily has high oral bioavailability
C. It may contain a structurally complex molecule with useful biological
activity
D. It has already satisfied regulatory requirements
Correct Answer: C. It may contain a structurally complex molecule with
useful biological activity
Rationale:
C is correct because natural products can provide chemically diverse
structures that interact with biological targets and may serve as leads
for drug development. A is incorrect because natural origin does not
, guarantee safety. B is incorrect because absorption and bioavailability
must be experimentally determined. D is incorrect because discovery
from a natural source does not establish regulatory approval.
Question 3
A compound isolated from a medicinal plant produces a promising
biological effect in an initial assay. Researchers then modify its chemical
structure to improve its properties. What is this process primarily
intended to accomplish?
A. Convert the compound into a placebo
B. Optimize the compound as a drug lead
C. Eliminate the need for biological testing
D. Replace pharmacological evaluation with chemical analysis
Correct Answer: B. Optimize the compound as a drug lead
Rationale:
B is correct because structural modification of an active compound can
improve properties such as potency, selectivity, pharmacokinetic
behavior, or tolerability. A is unrelated to lead optimization. C is
incorrect because modified compounds still require biological
evaluation. D is incorrect because chemical modification and biological
testing are complementary components of drug discovery.
Question 4
A medicinal chemist wants to determine which structural features of a
lead compound are responsible for its biological activity. Which
approach is most directly useful?