Isoprenoids sharks

Squalene is an isoprenoid compound that is found in large quantities in shark liver and in smaller quantities in olives, rice bran and wheat germ. It is a bactericidal compound and an antioxidant and it aids in skin nutrition. Several cosmetic applications of rice bran and rice bran oil arise from the biological effects of their squalene, vitamin E and y-oryzanol content. Since these compounds are fat-soluble, rice bran oil is used for all these preparations. 

Pristane, 2,6,10,14-Tetramethylpentadecane nor-phytane Robuoy. C. H mol wt 268.51. C 84,98%, H 15.02%. Isoprenoid alkane obtained from the unsaponifiable fraction of shark liver oil where it occurs to an extent of 14% Tsujimoto. J. Soc. Chem. Ind. 51, 3 7T (1932) Sorensen, Mehllum, Acta Chem. Scand. 2, 140 (1948). Identity with norphytane Pliva, Sorensen, ibid. 4, 846 (1950), Isoln from patroleum crude oils Bendoraitis et al. Anal Chem. 34, 49 (1962) from wool wax Mold et al. Nature 199, 283 (1963). Synthesis from phytol Sorensen, Sorensen, Acta... 

Definition Unsat. branched chain isoprenoid hydrocarbon found in shark liver oil Empiricai C30H50... 

Squalene, a hydrocarbon CaoHso, was first isolated from shark liver and is found in small amounts also in mammals. As is evident from the biosynthesis just discussed, squalene is an isoprenoid composed of two symmetrical halves. Among the formulas shown here, two ways of writing the same molecule are presented. The spatial arrangement indicated in the second formula permits cyclization to the steroid skeleton, after a preliminary hydroxylation. The first isolable product is lanosterol ... 

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