Home > A. Molecular pathology > squalene
squalene
Monday 21 July 2008
Squalene is a hydrocarbon and a triterpene. All higher organisms produce squalene, including humans.
Squalene is the biochemical precursor to the whole family of steroids.
Oxidation (via squalene monooxygenase) of one of the terminal double bonds of squalene yields 2,3-squalene oxide, which undergoes enzyme-catalyzed cyclization to afford lanosterol, which is then elaborated into cholesterol and other steroids.
Biosynthesis
The steroid synthesis pathway joins the intermediates isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) to geranyl pyrophosphate (GPP) then squalene.
Two molecules of farnesyl pyrophosphate (FPP) could also condense with reduction by NADPH to form squalene by squalene synthase.
In nature
Squalene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though there are botanic sources as well, including amaranth seed, rice bran, wheat germ, and olives.
Squalane is a saturated form of squalene in which the double bonds have been eliminated by hydrogenation. Because it is less susceptible to oxidation, it is more commonly used in personal care products than squalene.
See also
hydrocarbon
triterpene
