Selenium in garlic

S. McSheehy, W. Yang, F. Pannier, J. Szpunar, R. Lobinski, J. Auger, M. Potin-Gautier, Speciation analysis of selenium in garlic by two-dimensional high performance LC with parallel ICP-MS and ESI-MS detection, Anal. Chim. Acta, 421 (2000), 147 D153. 

Electrospray MS that allows a precise ( lDa) determination of molecular mass is an invaluable tool for the identification and a prerequisite for further characterization of compounds in speciation analysis. ESTMS has been applied mostly to commercial standards or synthetic preparations. Pneumatically assisted ESTMS is used to identify Se-adenosylhomocysteine in an extract of selenized yeast. Selenium in garlic has been speciated by parallel ICP-MS and electrospray tandem MS. A novel selenium metabolite in rat mine, the selenosugar di-asteriomer Se-methyl-N-acetylhexosamine, has been identified by this method. It should be emphasized that when authentic standards are not available the use of tandem MS is vital to confirm selenium speciation indicated by means of hyphenated seleni-mn-specific detection. 

Inam, R. and Somer, G. (1999) Determination of selenium in garlic by cathodic stripping voltammetry. Food Chem., 66, 381-385. 

Ip, C., Birringer, M., Block, E., Kotrebai, M., Tyson, J.F., Uden, P.C., and Lisk, D.J. 2000. Chemical speciation influences comparative activity of selenium-enriched garlic and yeast in mammary cancer prevention. J. Agric. Food Chem. 48, 2062-2070. 

Se Speciation in Plants The presence of a number of volatile Se species was reported in edible allium plants such as garlic by GC-AES [79]. Selenomethionine, Se-methylselenocysteine, and y-glutamyl-Se-methyl-L-seleno cysteine were identibed in garlic and onion by HPLC-ICP-MS and ES-MS/MS [80]. Selenomethionine is the primary species found in all types of nuts (19D25 percent of the total Se) [30], sunBower [81], and mushrooms [36, 37], The distribution of Se among different fractions (lipid extract, low molecular weight, and protein fractions) of nuts and speciation analysis was studied [30]. Selenium was not detected in any of the lipid extracts obtained from the different types of nuts [30], Results obtained for Brazil nuts by SEC with on-line ICP-MS detection showed that approximately 12 percent of total Se was weakly bound to proteins [30],... 

Specific biomarkers of selenium effects were not found. Garlic breath is a marker of over-exposure to selenium compounds. However, as other metals that are methylated (e.g., arsenic) also result in garlic odor of the breath, this effect is not a unique marker of selenium over-exposure. Hair and nail effects may be the most frequent effects of overexposure to selenium. Hair becomes dry and brittle and breaks... 

IpC,LiskDJ. 1996. The attributes of selenium-enriched garlic in cancer prevention. In American Institute for Cancer Research, eds. Dietary phytochemicals in cancer prevention and treatment. New York, NY Plenum Press, 179-187. 

Keshan disease, a form of cardiomyopathy. When its intake is too high, selenium disrupts enzyme function, causing poor health in mammals and birth defects and reproductive failure in birds and fish. Good sources of selenium in human diets include wheat, garlic, Brazil nuts, and walnuts, see also Chalcogens. 

The unusual physical complaints and findings in workers overexposed to teUurium include somnolence, anorexia, nausea, perspiration, a metallic taste in the mouth and garlic-like odor on the breath (48). The unpleasant odor, attributed to the formation of dimethyl teUuride, has not been associated with any adverse health symptoms. Tellurium compounds and metaboUc products have been identified in exhaled breath, sweat, urine, and feces. Elimination is relatively slow and continuous exposure may result in some accumulation. No definite pathological effects have been observed beyond the physical complaints outlined. Unlike selenium, teUurium has not been proved to be an essential biological trace element. 

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