Shark liver, oil

Pnstane is an alkane that is present to the extent of about 14% in shark liver oil Its lUPAC name is 2 6 10 14 tetramethylpentadecane Write its structural formula... 

Haifisch-ledcr, n. shark leather. -tran, m. shark-liver oil. 

Cod liver oil and shark liver oil Rich source of vitamin A and D. 

Shark liver oil Vitamin A Livers of shark and allied species... 

The all-tra 5 -squalene (C30H50), discovered in shark liver oil in the 1920s, is a triterpene, but one in which the isoprene rule at violated in one point. Rather than a head-to-tail arrangement of six units of isoprene, there appear to be farnesyl units that have been connected tail to tail. Almost aU steroids are biosynthesized from cholesterol. Cholesterol is biosynthesized from squalene, which is first converted to lanosterol. The conversion of squalene to the steroid skeleton is an oxirane, squalene-2,3-oxide, which is transformed by enzymes into lanosterol, a steroid alcohol naturally found in wool fat. The whole process is highly stereoselective. 

Squalene is a polyunsaturated hydrocarbon with a formula of C30H50 Squalene can be found in certain fish oils, especially shark liver oil, in high amounts and some vegetable oils in relatively smaller amounts. Human sebum also contains 13% squalene as one of its major constituents. Squalane is a saturated derivative of squalene and also found in these sources. Interest in squalene has been raised after its characterization in shark liver oil which is used as a traditional medicine for decades. Several studies exhibited results that prove certain bioactivities for squalene and squalane. Up to date, anticancer, antioxidant, drug carrier, detoxifier, skin hydrating, and emollient activities of these substances have been... 

These two components in shark liver oil have been used as traditional medicine for ages in order to keep people healthy. After their characterization, and highly intensified researches for their bioactivities, they are still important factors of supplementary diet for a healthier living. Up to date, several researches brought novel insights to their properties and proved various beneficial uses of these compounds. 

Nowicki and Bara ska-Rybak (2007) studied the protective effect of shark liver oil. They observed a significant protection against bacterial and fungal infections by shark liver oil treatment which contains mostly squalene and alkylglycerol. Further, this treatment showed improved effects on xerosis and skin lesion-induced atopic dermatitis. This antibacterial and antifungal effect could be accounted for the high-squalene-including composition of the shark liver oil however, detailed studies are needed to be carried out for reputed activity of squalene as an anti-infectant. 

Detoxifying and anti-infectant effects of squalene itself have not been reported yet. However, substances including squalene or squalene supplementation showed notable improvements. Further researches to elucidate the underlying mechanisms of shark liver oil and squalene application are expected to report more results that promote squalene and squalane as effective candidates for practical and clinical use. 

Nowicki, R. and Bara ska-Rybak, W. (2007). Shark liver oil as a supporting therapy in atopic dermatitis. Pol. Merkur. Lekarski. 22, 312-313. 

Peniche et al. (2004) successfully encapsulated up to 65 % of shark liver oil (rich in polyunsaturated fatty acids) in chitosan/alginate capsules in order to mask the oil s unpleasant taste. Here again it was found that the chitosan coating allowed a greater degree of control of capsule permeability. The capsules could be degraded by enzymes such as lipase or pancreatin. They were initially resistant to the acid environment of the stomach, although after 4 hours under intestinal conditions (pH = 7.4) the capsule walls were finally disrupted. 

Peniche, C., Howland, I., Carrillo, O., Zaldivar, C., Argqelles-Monal, W. (2004). Formation and stability of shark liver oil loaded chitosan/calcium alginate capsules. FoodHy-drocolloids, 18, 865-871. 

During early pregnancy, high doses of vitamin A (as found in halibut and shark liver oils) can lead to birth defects (15). Fish oil supplements rich in vitamin A should therefore be avoided by women in the first trimester and those who might become pregnant. 

Diaz-Rojas, E.I., Pacheco-Aguilar, R., Lizardi, J., Arguelles-Monal, W., Valdez, M.A., Rinaudo, M., and Goycoolea, F.M. 2004. Linseed pectin Gelling properties and performance as an encapsulation matrix for shark liver oil. Food Hydrocolloids 18, 293-304. 

Figure 24.3. Chemical structure of chimyl (4), batyl (5) and selachyl (6) alcohols, the three most prevalent l-O-alkyl-sn-glycerols in shark liver oil.

The advantage of complex coacervates is that high payloads can be obtained. Chitosan/alginate coacervates have been reported to encapsulate up to 87% shark liver oil, which is rich in omega-3 fatty acids (Peniche et al. 2004). Microspheres of carboxymethyl chitosan/alginate hardened with calcium chloride have been used for encapsulation of up to 80% bovine serum albumin (Zhang et al. 2004). 

Figure 4. Phytol and phytol-related hydrocarbons, pristane and phytane, are associated and may be found in some fish oils. Phytanic, pristanic, and 4,8,12-trimethyitridecanoic acids are common fish oil components derived from phytol. Squalene is usually of animal origin and a feature of some shark liver oils.

Lipid nutritional supplements have been in use before the term nutraceutical was coined. Products such as fish oils, shark cartilage, shark liver oil, and vitamins have been in the market since the beginning of the twentieth century. Some of the health claims of these products lacked strict scientific documentation in the past, and their curative properties were mostly anecdotal. However, today there is a better understanding of the biological properties of lipids and their application has extended to combined pharmaceutical and cosmetic fields such as disease prevention and treatment, excipients and coadjuvants, frawi-dermal carriers, and skin emolliency agents. This has led to the development of bioactive cosmetic and pharmaceutical products whose name has recently been coined as cosmeceuticals. 

Squalene is a popular over-the-counter Asian folk remedy derived from shark liver oil. Oral capsules are readily available in Asian health food stores and the substance is also widely used in cosmetics. 

---