- A hexaisoprenoid (triterpenoid) hydrocarbon found in shark oil and in some plants; intermediate in the biosynthesis of cholesterol and other sterols and triterpenes.- s. epoxidase an enzyme that catalyzes the conversion of s. to s. 2,3-oxide in the endoplasmic reticulum; a required step in order for cyclization to occur, resulting in the synthesis of the first sterol, lanosterol, in steroidogenesis; uses NADPH.- s. synthase an enzyme that catalyzes the formation of s. from two molecules of farnesylpyrophosphate using NADPH and concomitant production of two molecules of pyrophosphate.
* * *squa·lene 'skwā-.lēn n an acyclic hydrocarbon C30H50 that is widely distributed in nature (as a major component of sebum and in shark-liver oils) and is a precursor of sterols (as cholesterol)
* * *n.
* * *squa·lene (skwaґlēn) [first isolated from Squalus, a genus of sharks] an unsaturated, symmetrical, 30-carbon triterpene intermediate formed in the biosynthesis of cholesterol and all other cyclic triterpenes. It can be isolated from shark and other fish oils and some plants.
Medical dictionary. 2011.