Natural Product–Derived Drugs

Natural product–derived drugs are medicines whose active structures originate in, or are inspired by, compounds made by living organisms — plants, microbes, fungi, and marine life. These molecules, used directly, modified semi-synthetically, or imitated by total synthesis, account for a large share of approved drugs and contribute scaffolds whose structural complexity often lies beyond what synthetic libraries readily produce.

Definition

A natural product–derived drug is a therapeutic agent whose active molecular structure is a naturally occurring compound, a chemically modified (semi-synthetic) derivative of one, or a synthetic molecule whose design is based on a natural-product scaffold.

Scope

This topic covers the place of natural products in the chemical classification of drugs: how naturally occurring compounds become medicines through direct use, semi-synthesis, or natural-product-inspired design, and the distinctive structural features of these scaffolds. It is an educational overview of a structural and source-based class and offers no guidance on the clinical use of any specific natural-product–derived agent.

Core questions

• How do natural products enter the drug supply — as isolated compounds, semi-synthetic derivatives, or synthetic mimics?
• What structural features distinguish natural-product scaffolds from typical synthetic small molecules?
• Why do natural products remain a productive source of new drugs?
• How are naturally derived agents classified relative to fully synthetic ones?

Key concepts

• Isolated natural products
• Semi-synthetic derivatives
• Natural-product–inspired synthesis
• Structural and stereochemical complexity
• Secondary metabolites
• Biosynthetic origin
• Scaffold diversity

Mechanisms

Natural products reach the clinic along several routes. Some are used essentially unchanged as isolated compounds; others are semi-synthetic, in which a naturally produced core is chemically modified to improve potency, stability, or tolerability; and still others are fully synthetic molecules whose design copies or simplifies a natural scaffold. Structurally, natural products tend to be richer in stereocentres, ring systems, and oxygen content than typical synthetic drugs, occupying regions of chemical space that medicinal chemists value precisely because they differ from synthetic libraries. Newman and Cragg's long-running surveys document that, across decades of approvals, a substantial fraction of new drugs are natural products, their derivatives, or natural-product mimics, underscoring the continuing contribution of this source.

Clinical relevance

Many widely used therapeutic classes trace their structures to natural products, so this source-based category helps explain the chemical diversity of the pharmacopoeia and the origins of important scaffolds. The entry describes how such drugs are classified and where their structures come from; it is background information and not advice on using any particular natural-product–derived medicine.

Evidence & guidelines

The role of natural products in the drug supply is documented in systematic surveys of approved new molecular entities, most prominently the periodically updated analyses by Newman and Cragg, complemented by biosynthesis-oriented reference texts. These describe historical and structural patterns rather than prescribing clinical practice.

History

Natural products are the oldest source of medicines, from plant alkaloids isolated in the early nineteenth century to antibiotics discovered from microbes in the twentieth. As synthetic chemistry expanded, interest periodically shifted toward fully synthetic libraries, but recurring surveys of drug approvals have repeatedly shown that natural products and their derivatives remain a major wellspring of new chemical scaffolds, sustaining the field's interest in naturally derived structures.

Debates

What share of new drugs truly derives from natural products?

Estimates depend on how 'natural-product–derived', 'semi-synthetic', and 'natural-product–inspired' are defined; Newman and Cragg's classification scheme is influential but its category boundaries are themselves discussed in the literature.

Key figures

• David Newman
• Gordon Cragg
• Paul Dewick

Seminal works

• newman-cragg-2016

Frequently asked questions

What is a natural product–derived drug?

It is a medicine whose active structure comes from a compound made by a living organism — used directly, chemically modified as a semi-synthetic derivative, or copied by synthesis as a natural-product–inspired molecule.

Why are natural products still important in drug discovery?

Natural products offer structurally complex and diverse scaffolds that differ from typical synthetic libraries, and surveys of drug approvals show they continue to contribute a large share of new medicines.