ABSTRACT
Therapeutic agents are chemical entities that prevent disease, assist in restoring health to the diseased, or alleviate symptoms associated with disease conditions. Medicinal chemistry is the scientic discipline that makes such drugs available either through discovery or design processes. Throughout history, drugs were primarily discovered by empirical methods, investigating substances or preparations of materials, such as plant parts or plant extracts, found in the local environment. Over the previous centuries, chemists developed methods for the isolation and purication of the active principles in medicinal plants. The purication and structure determination of natural products like morphine, hyoscyamine, quinine, and digitalis glycosides represent milestones in the eld of drug discovery and the beginning of medicinal chemistry as a fascinating independent eld of research (Figure 1.1).
