Pasteurin

Pasteurin is a fictional natural product commonly used in textbooks and problem sets to illustrate principles of natural product biosynthesis, structure–activity relationships, and pharmacology. The term is not associated with a validated compound in chemical databases, and there are no experimental data describing its isolation or properties outside hypothetical scenarios.

In typical educational depictions, pasteurin is described as a lipophilic secondary metabolite produced by a hypothetical soil bacterium. Its proposed structure is often a macrocyclic or polycyclic scaffold with a polyene backbone, several heteroatoms (such as oxygen), and multiple functional groups capable of hydrogen bonding. Because the exact architecture varies between examples, discussions focus on generic features rather than a single real-world structure.

Biosynthesis is usually shown as being guided by a modular polyketide synthase (PKS) gene cluster, with downstream tailoring enzymes introducing double bonds, epoxidations, and oxidations that generate diversity. The name pasteurin is sometimes said to derive from Pasteur as a teaching mnemonic, though it has no historical linkage to a discovered organism or product.

Educational relevance includes demonstrations of gene cluster engineering, heterologous expression, and structure–activity relationships. It also serves as a talking point for challenges in natural product discovery, such as dereplication and the need for independent synthesis and verification.

See also: polyketide synthases, natural product biosynthesis, educational resources.