Polyisoprenoids

Polyisoprenoids are a large and diverse class of naturally occurring organic compounds. They are polymers synthesized from isoprene units, which are five-carbon building blocks with the chemical formula C5H8. These isoprene units are linked together in various ways, leading to a wide range of structures and functions. The repeating unit in a polyisoprenoid is often referred to as an isoprenoid unit or a terpene unit.

The synthesis of polyisoprenoids in living organisms is a fundamental metabolic process. The isoprene units are typically derived from intermediates of the mevalonate pathway or the methylerythritol phosphate pathway. These pathways are crucial for the biosynthesis of many other essential molecules, including steroids and fat-soluble vitamins.

Polyisoprenoids play vital roles in biological systems. They include compounds like rubber, which is a major component of latex produced by rubber trees. Other examples include carotenoids, which are pigments found in plants and algae, and are essential for photosynthesis and as antioxidants. Many vitamins, such as vitamin A and vitamin E, are also polyisoprenoids or contain polyisoprenoid chains. Furthermore, some bacterial cell wall components and animal lipid structures are polyisoprenoid-based. The structural diversity of polyisoprenoids allows for a broad spectrum of biological activities and applications.