Cholesterol
Cholesterol is a molecule that is found in animal cells and body fluids. Cholesterol is not found in plant sources. It is a type of lipid which is a fat or fat-like molecule. Cholesterol is a soft waxy substance. Cholesterol is a special type of lipid that is called a steroid. Steroids are lipids that have a special chemical structure. This structure is made of four rings of carbon atoms. Cholesterol is found especially in animal fats.
Cholesterol is the main steroid synthesized by animals. Other steroids include hormone steroids like cortisol, estrogen, and testosterone. These and other steroid hormones are made by changing the basic chemical structure of cholesterol. This is an example of chemical synthesis.
Hypercholesterolemia means that cholesterol level is too high in the blood. High cholesterol levels show that heart disease may develop.
Biosynthesis
Cholesterol biosynthetic pathway
Lovastatin
Architecture of the lovastatin type I PKS system. Outlined domains are used iteratively. ACP- acyl carrier protein, AD-alcohol dehydrogenase, AT-acyltransferase, DH-dehydratase, KS-ketoacyl synthase, KR-ketoreductase, MT-methyltransferase, ER-enoylreductase, C-condensation, TE-thioesterase. (*)-redundant domain/inactive not used in this step.
Biosynthesis of lovastatin
HMG CoA reductase reaction
Biosynthesis using Diels-Alder catalyzed cyclization
Biosynthesis using broadly specific acyltransferase
Synthesis of compounds 1 and 2
Complete lovastatin synthesis
Additional images
Cholesterol units conversion
Steroidogenesis, using cholesterol as building material
Space-filling model of the Cholesterol molecule
Numbering of the steroid nuclei