Onion metabolism

Srivastava KC. (1984). Aqueous extracts of onion, garlic and ginger inhibit platelet aggregation and alter arachidonic acid metabolism. Biomed Biochim Acta. 43(8-9) S335-46. 

Many organosulfur compounds undergo biological oxidation at the sulfur atom to yield products which have pronounced physiological activity or serve as intermediates in generating bioactive compounds. Three examples are the lachrymating agent in onions ( ) (1), the oxo intermediate ( ) in metabolic desulfuration of phosphorothionate insecticides to form potent cholinesterase inhibitors (2), and the sulfoxides QJ produced on metabolism of thiocarbamate herbicides (3). 

Dimethyl sulfoxide occurs widely at levels of <3 ppm. It has been isolated from spearmint oil, com, barley, malt, alfalfa, beets, cabbage, cucumbers, oats, onion, Swiss chard, tomatoes, raspberries, beer, coffee, milk., and tea (5). It is a common constituent of natural waters, and it occurs in seawater in the zone of light penetration where it may represent a product of algal metabolism (6). Its occurrence in rainwater may result from oxidation of atmospheric dimethyl sulfide, which occurs as part of the natural transfer of sulfur of biological origin (7,8). 

Mullen W, Edwards CA, Crozier A. 2006. Absorption, excretion and metabolic profiling of methyl-, glucuronyl-, glucosyl and sulpho-conjugates of quercetin in human plasma and urine after ingestion of onions. Brit J Nutr 96 107-116. 

The effects of onion and garlic on eicosanoid metabolism have mainly been studied by observing the effects of garlic and onion preparations on platelet aggregation and subsequent eicosanoid synthesis. 

Ali, M., Thomson, M., and Afzal, M., Garlic and onions their effect on eicosanoid metabolism and its clinical relevance, Prostaglandins Leukot. Essent. Fatty Acids, 62, 55-73, 2000. 

Srivastava KC. Effects of aqueous extracts of onion, garlic, and ginger on platelet aggregation and metabolism of arachidonic acid in the blood vascular system in vitro study. Prostagland Leukotr Med 1984 13 227-235. 

Fructans are oligomers and polymers formed by polymerizing fructose from transport metabolite sucrose on one out of three possible starter trioses 1-kestose yields inulin-type (2 1)-p-D-fructans, 6-kestose yields levan-type (2 6)-p-D-fructans (Fig. 3A), and neo-kes-tose yields mixcD-type and/or branched (2 1), (2 6)-p-D-fructans (Fig. 3C). Pronounced fructan metabolism is found in composites (chicory, Jerusalem artichoke), Liliaceae (onion, chives, garlic), cereals (wheat, barley, rye, oat), Asparagaceae (asparagus), Amaryllidaceae (banana), and Agavaceae (agave). 

Formaldehyde, a strong irritant, is considered one of these aggressors. Since it is a well defined chemical, it has become an easy target for elimination. However, we should remember that formaldehyde is not only an industrial chemical, but is omnipresent in nature Formaldehyde is present in traces in the living organism where it plays an important part in the metabolic cycles (biosynthesis of the puric nucleus). We can find it in apples, onions, etc. It was also one of the first organic compounds discovered in interstellar space. In fact, in the direction of... 

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