3,5-dihydroxy-3-methyl-valeric acid, an important intermediary product of metabolism. Colorless water-soluble crystals. Melting point, 27°C; readily undergoes dehydration to form the corresponding 8-lactone (mevalolactone):

Physiologically active mevalonic acid is a ( + )-isomer. Mavelonic acid was discovered and isolated by American microbiologists (C. Folkers and others) in 1956. It is widely distributed in plants and animals.

The biosynthesis of mevalonic acid takes place in the microsomes of cells, with participation of three acetyl radicals. The resulting product of condensation undergoes irreversible reduction to mevalonic acid, which means that the latter may be regarded as a specific biogenetic unit. In nature, mevalonic acid is the initial material for the creation of a broad class of natural compounds, the isoprenoids. Synthetic mevalonic acid with an isotopic tag is widely used in studying the biosynthesis of various isoprenoids in organisms, as well as in acellular systems.