Sterols algal

Sterols and their respective derivatives have proven to be important biomarkers that can be used to estimate algal and terrestrial contributions as well as dia-genetic proxies. These compounds are a group of lipids (typically between C26 and C30) that are resistant to saponification and can be classified as triterpenes. 

Piretti M., Pagliuca G., Boni L., Pistocchi R., Diamante M., and Gazzotti T. (1997) Investigation of 4-methyI sterols from cultured dinoflagellate algal strains. J. Phycol. 33, 61 -67. 

Methyl sterols are widespread in higher plants in traces whereas 24)8-ethyl sterols are rather rare. Recent work has shown that higher plants utilize the green algal pathway to produce these stereoisomers. 

Fig. 14. The stereochemistry of desaturation of C>22,23 in higher plant algal and fungal sterols [9].

The incorporation of labelled acetate into cholesterol in coelenterata has not been demonstrated. Thus, it is likely that various sterols in coelenterata are of algal origin. They may be obtained either in the diet or by transfer from symbiotic zooxanthellae. 

Potential Beneficial Effects of Marine Algal Sterols on Human Health... 

This finding indicated the presences of sterols may have effect on MDR M. tuberculosis. Therefore, marine algal sterols have potential in the development of urgently needed tuberculosis drugs. 

Bivalves have a limited capacity to synthesize sterols de novo (Holden and Patterson, 1991) so dietary sterols from microalgae could be important in their nutrition. For post-larval P. magellanicus, the combination of C muelleri with Pavlova spp. produced higher growth rates than other algal diets tested, which was attributed to the comparatively high proportion of cholesterol in sterols from C. muelleri (Milke et al, 2008). Of the other... 

In fungal sterol biosynthesis the A - A -double bond isomerisation involves the loss of the 70-hydrogen (derived biosynthetically from the 2-pro-R hydrogen of (-i-)-R-mevalonic acid [MVA]), whereas in animal, higher plant and chlorophyte algal sterol biosynthesis the 7p-hydrogen (ex 2-pro-S H of MVA) is lost. 

Anjaneyulu ASR, Prakash CVS, Mallavadhani UV (1991) Sterols and terpenes of the marine green algal species Caulerpa racemosa and Codium decorticatum. J Indian Chem Soc 68 480... 

In response to a decrease in temperature algal cells increased their total lipid content. Low temperature led to a 51 % increase in the level of oleate whilst levels of linoleate and parinate (18 4) decreased, by 81 % and 43 % respectively, when compared to control cells. Low temperature also significantly affects the sterol profile, leading to a 48 % increase in 24-methylcholest-7-en-3(3-ol (MC-7), and a decrease in the ratio of EC-7,22 to EC-7 from 0.41 to 0.28. 

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