Allium sulfur compounds

Allium Sulfur compounds, Hypercholesterolemia Induction or Saquinavir, [44,46,47,60,66-68,11 7,119,125-128]... 

Plants of the genus Allium, e.g. garlic Allium sativum), leek Allium amp-eloprasum), and onion Allium cepa), produce a bewildering variety of sulfur compounds. Selenium analogs for some of these have also been found (Section 11.1.3.6). Much work has focused on garlic (contains more than 100 such materials) and onion.56,66,67 Key compounds for formation of the Allium sulfur-containing secondary metabolites are sulfoxides of cysteine derivatives,... 

Garlic, Allium sativum L., is a species in the onion family, Alliaceae. Onion, shallot, and leek are close relatives. Garlic has been used throughout history for both culinary and medicinal purposes. It has a pungent hot sensation that mellows and sweetens considerably with cooking. A large number of sulfur compounds contribute to the smell and taste of members of the onion family. Diallyl disulfide and diallyl sulfide are... 

Members of the allium family (onions, garlic, and leeks) contain cysteine sulfoxide derivatives (allyl sulfur compounds), such as allicin and alliin (see Figure 14.9). When the plant cells are damaged, the enzyme alliinase is released from vacuoles and catalyzes the formation of thiosulfinates and thiols, including the lachrymator thiopropanal S-oxide. Their function in the plant is presumably to provide protection against attack by pests. 

A large number of organic sulfur compounds have been detected in extracts or distillates prepared from garlic, onions, or other Allium species. This chemistry has been reviewed by Block. Polysulfanes have been detected in many of these preparations but most recent results show that fresh extracts of garlic, prepared under mild conditions (20 °C), did not show any polysulfanes R-S -R n > 2) when analyzed by RP-HPLC analysis. ... 

Onions Allium cepa) were shown to contain similar compounds, S-methyl and S-propyl-L-cysteine sulfoxide (20). The principal flavor precursor in onion is fmn -S( + )-l-propenyl-L-cysteine sulfoxide 21, 22, 23). It is responsible for the lachrymatory properties and bitter taste of freshly cut onion (22). All these compounds were cleaved by an S-alkyl-L-cysteine sulfoxide lyase from onion 24, 25) which yielded pyruvate and ammonia in addition to a sulfur compound. The enzyme has also been demonstrated in Bacillus subtilis 26) and in a number of the Cruciferae where the only substrate known is S-methyl-L-cysteine sulfoxide (27). The product presumably gives rise to dimethyl disulfide which is the odor of cooked cabbage. 

Block, E. and Calvey, E.E., Facts and artifacts in allium chemistry, in Sulfur Compounds in Foods, Mussinan, C.J. and Keelan, M.E., Eds., American Chemical Society, Washington, D.C., 1994, p. 63. 

Alliums are garlic, onions, scallions, shallots, ramps, leeks, and chives, which are all botanically related. Although they are usually thought of as foods, these powerful herbs contain many active sulfur compounds that have shown the ability to prevent cancer. 

Naturally occurring sulfur-containing compounds are found especially in the cruciferous vegetables, such as broccoli, brussels sprouts, cabbage, kale, and tnmips (Brassica spp.), and the onion Allium spp.) and mustard (Sinapis spp.) families. The sulfur compounds in these groups are slightly different and, consequently, each has specific health benefits. 

Puxbaum, H. and G. Konig (1997) Observation of dipropenyldisulfide and other organic sulfur compounds in the atmosphere of a beech forest with Allium Ursinum ground cover. Atmospheric Environment 31, 291-294... 

Several sulfiir-containing amino acids, other than cysteine, cystine, and methionine, are found in higher plants. Allium (Liliaceae) species often contain sulfur compounds that are lachrymatory in nature (Fig. 13.17). Among these species are chives, garlic, onion, and leeks. The compounds involved are 5-substituted cysteine sulfoxides and their hydrolysis... 

Fig. 13.15. Sulfur compounds found in Allium species and formation of i yn-propanethial S-oxide (Luckner, 1990).

For years researchers have investigated the sulfur compounds present in various foods. Cooked foods typically contain numerous sulfur compounds, especially heterocyclic compounds like thiazoles, thiophenes, thiazolines, etc. In 1986, Sha-hidi et al. (7) reported that 144 sulfur compounds had been identified in beef. Other heated food systems like bread, potato products, nuts, popcorn, and coffee also contain many sulfur compounds. Aliphatic thiols have been found in fruits, vegetables, dairy products etc., as well as in heated foods. No discussion of the occurrence of sulfur compounds in foods would be complete without mention of their major role in the various allium species. Indeed, more than half of the volatile compounds reported in garlic, onion, leek, and chive contain sulfur (2). Comprehensive reviews of the literature concerning the role of thiazoles, thiophenes, and thiols in food flavor through 1975 can be found in Maga s series of review articles (3-5). 

Garlic of Allium genus, one of the most widely known spices in the world, is noted for the enzymatic formation of a large amount of organic sulfur compounds when it is crushed. The powerful flavor and possible medical application of the... 

The identified components and their peak areas by GC are listed in Tables I and II. For both the fruits and leaves, the composition of the volatiles was relatively simple. In the headspace volatiles, ethanal was the main component (96.4%). This compound is probably produced in the fruit during storage from pyruvic acid by decarboxylation under anaerobic respiration (4). Among the other compounds were dimethyl sulfide, dimethyl disulfide, and methane- and propane-thiols, together with two unusual polysulfides which have not been found in the Allium species. The sulfur compounds in the leaves were similar to those found in the fruit, but the concentrations of ( )-2-hexenal and (Z)-3-hexenol, which are well known to be responsible for a green note (5), were much higher than found in the fruit. 

Block E, Dane AJ, Thomas S, et al. Applications of direct analysis in real time mass spectrometry (DART-MS) in allium chemistry. 2-propenesulfenic and 2-propenesufinic acids, diallyl trisulfane S-oxide, and other reactive sulfur compounds fiom crushed garlic and other alliums. J Agric Food Chem. 2010 58 4617-25. 

Kyung KH, Lee YC (2001) Antimicrobial activities of sulfur compounds derived from S-alk (en) yl-L-cysteine sulfoxides in Allium and Brassica. Food Rev Int 17 183-198 Lee YS, Kang OH, Choi JG, Oh YC, Keum JH, Kim SB, Jeong GS, Kim YC, Shin DW, Kwon DY (2010) Synergistic effect of emodin in combination with ampicillin or oxacillin against methicUlin-resistant Staphylococcus aureus. Pharm Biol 48 1285-1290 Li Y, Du Y, Zou C (2009) Effects of pH on antioxidant and antimicrobial properties of tea saponins. Eur Food Res Technol 228 1023-1028... 

Kubec R., KrejiovA P., Simek P., Vaclavik L., Hajslova J., Schraml J. Precursors and formation of pyrithione and other pyridyl-containing sulfur compounds in drumstick onion. Allium stipitatum. Journal of the Agricultural and Food Chemistry, 59 5763-5770 (2011). 

Scheme 7.3 Enzymatic production of sulfur-containing flavour compounds in Allium species from amino acid flavour precursors, a S-Alk(en)yl cysteine sulfoxides and b (+)-S-l-propenyl cysteine sulfoxide (isoalliin) P-5 -Ppyridoxal-5 -phosphate...

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