Phase 5 – SAR Analysis & Lead Optimization
Phase 5 – SAR Analysis & Lead Optimization contains 15 topic pages in Pharmaceutical Chemistry.
Learning Objectives
- Explain the concept of structure–activity relationship and how it guides medicinal chemistry design.
- Describe bioisosteric replacement, functional group modification, and ring modification as SAR strategies.
- Explain how lipophilicity, electronic, and steric effects influence potency and drug-like properties.
- Describe prodrug design as a strategy for overcoming pharmacokinetic liabilities.
- Explain how ADMET optimization and patentability considerations inform final candidate selection.
- Identify career pathways available to medicinal chemistry graduates and the future trajectory of the discipline.
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Topics and Topic Groups
Browse the available learning units in this chapter.
Structure–Activity Relationship (SAR)
Introduction and Principle Structure–activity relationship analysis is the systematic study of how specific structural features of a molecule influence its...
Bioisosteric Replacement
Bioisosterism is the strategic replacement of a specific functional group or structural fragment within a lead compound with an alternative group — a...
Functional Group Modification
Functional group modification systematically alters a specific chemical group within a lead compound — converting an ester to an amide, a ketone to an...
Ring Modification
Ring modification alters the size, saturation, or heteroatom composition of a cyclic structural element within a lead compound — for example, contracting a...
Lipophilicity Optimization
Lipophilicity, most commonly quantified as logP (the logarithm of the octanol-water partition coefficient) or logD (the pH-adjusted equivalent accounting...
Electronic Effects
Electronic effects — the influence of substituent electron-donating or electron-withdrawing character on a molecule's reactivity, acidity or basicity, and...
Steric Effects
Steric effects — the influence of substituent size and three-dimensional bulk on a molecule's ability to access its target binding site — are probed by...
Prodrug Design
Prodrug design deliberately masks an active compound's pharmacologically essential but pharmacokinetically problematic functional group with a chemically...
Lead Optimization: Integrated Strategy
Lead optimization, introduced conceptually in the opening phase of this text, integrates every strategy described above — bioisosteric replacement,...
ADMET Optimization
ADMET optimization applies the same structure-driven design strategies used for potency optimization to the systematic improvement of a compound's...
Drug Metabolism Considerations
Drug metabolism, predominantly mediated by hepatic cytochrome P450 enzymes, determines both a compound's systemic half-life and its potential for clinically...
Patentability
Patentability assessment runs alongside the scientific optimization process throughout lead optimization, since a candidate compound's commercial viability...
Drug Candidate Selection
Drug candidate selection is the culminating decision point of the medicinal chemistry discovery process, at which a single compound, or occasionally a small...
Career Opportunities in Medicinal Chemistry
A medicinal chemistry specialisation opens a diverse range of career pathways across pharmaceutical industry, contract research, computational science, and...
Future Scope of Medicinal Chemistry
Medicinal chemistry continues to evolve rapidly at the intersection of chemistry, structural biology, and computational...