Cystein sulphoxides

Synthetic peptide inhibitors have been developed for a variety of proteases [199-204]. Peptide inhibitors of the metalloprotease angiotensin I converting enzyme (ACE) are of major importance as hypertensive agents [13, 31]. A variety of peptides derived from protease-catalyzed hydrolysis of com cc-zein [202-203] or of wheat germ protein [199, 204] inhibit ACE (Table 6). The most potent of such plant-derived ACE inhibitory peptides is Ile-Val-Tyr (IVY) (Ki 0.1 xM) [199, 204], Further plant-derived peptide ACE inhibitors include the tripeptide glutathione [73, 82], the glutathione -related peptide Y-L-glutamyl-(+)-allyl-L-cysteine sulphoxide [73, 82, 200, 201] and the tripeptide His-His-Leu (HHL) from fermented soybean [201] (Table 6). 

Organosulphur compounds, e.g., S-methyl cysteine sulphoxide (SMCSO) and its metabolite methyl methane thiosulphinate, both naturally occurring compounds present in Brassica vegetables (broccoli, cabbage) were found to inhibit benzo[a]pyrene-induced micronucleus formation in mouse bone marrow by 31 and 33%, respectively, after oral administration (Marks et al. 1993). 

Marks HS, Anderson JA, Stoewsand GS. 1993. Effect of S-methyl cysteine sulphoxide and its metabolite methyl methane thiosulphinate, both occuring naturally in brassica vegetables, on mouse genotoxicity. Food Chem Toxic 31 (7) 491-495. 

Y-L-Glutamyl-(+)-allyl-L-cysteine sulphoxide (dipeptide) Allium ursinum (Alliaceae) ACE (98 pM) [73, 82, 200, 201]... 

Drugs with Cysteine sulphoxides and Thiosulphinates Allium sativum L Allium ursinum L, Allium cepa L. - Alliaceae... 

Allium sativum and Allium ursinum preparations show a very similar qualitative composition of sulphur-containing compounds. Quantitative diiTerences are knovm for alliin/allicin and other cysteine sulphoxides and thiosulphinates, respectively. 

This compound was isolated from seeds of Allium schoenoprasum. The structure was established by enzymatic hydrolysis to give L-glutamic acid, S-(prop-l-enyl)-cysteine and S-(prop-l-enyl)-cysteine sulphoxide, determination of the N-terminal by dinitrophenylation and determination of the C-terminal by enzymatic treatment with carboxypeptidase A, which only hydrolyzes normal peptide bonds and therefore gave rise to S-(prop-l-enyl)-cysteine sulphoxide and y-glutamyl-S-(prop-l-enyl)-cys-teine. The L-configuration of the S-(prop-l-enyl)-cysteine sulphoxide was established by enzymatic analysis (215). 

C-Valine is incorporated into the S-substituents in S-(2-carboxy-propyl)-glutathione and S-(2-carboxypropyl)-cysteine in Allium sativum, and on this basis it was proposed that valine was transformed into methacrylic acid to which was added glutathione or cysteine, respectively 321). In this connection studies on the biosynthesis of S-(prop-l-enyl)-cysteine sulphoxide in Allium cepa which support a pathway from valine via methacrylic acid, S-(2-carboxypropyl)-cysteine, and S-(prop-l-enyl)-cysteine are of interest (75). 

Kupiecki, F. P., and A. I. Virtanen Cleavage of allyl cysteine sulphoxides by an enzyme in onion (Allium cepa). Acta Chem. Scand. 14, 1913 (1960). 

Proofs of the presence of 7-L-glutamyl-S-(l-propenyl)cysteine sulphoxide and... 

Treatment of alloxan diabetic rats with S-allyl cysteine sulphoxide isolated from garlic Allium sativum L.), amehorated the diabetic condition almost to the same extent as did glibenclamide and insulin (Augusti and Sheela 1996). S-Allyl cysteine sulphoxide significantly stimulated in vitro in-... 

The principal component of the lachrymatory factor of the onion (Allium cepa) has been identified by flash vacuum pyrolysis (FVP)/microwave techniques as (Z)-propanethial 5-oxide, CH3CH2CH=S=0. It functions as a 1,3-dipole and as a dipolarophile, and it dimerizes in cold benzene to give principally trans-3,4-diethyl-1,2-dithietan 1,1-dioxide rather than 2,4-diethyl-1,3-dithietan 1,3-dioxide, as previously proposed. Formation of this sulphine from its cellular precursor, rran5-(+)-S-(prop-l-enyi)-L-cysteine sulphoxide, is suggested to involve the formation of a Schiff base and the elimination of ( )-prop-l-enesulphenic acid, which then rearranges to the sulphine (Scheme 2). 

Lancaster, J.E., Shaw, M.L., and Randle, W.M. 1998. Differential hydrolysis of alk(en)yl cysteine sulphoxides by afliinase in onion macerates Elavour implications. J Sci Food Agric 75 367-yii. 

Sheela, C.G. and August , K.T. 1992. Antidiabetic effects of S-allyl cysteine sulphoxide isolated from garlic Allium sativum Linn. Indian J Exp Biol 30 6) 523-526. 

Kale contains an imbalance of trace elements such as iodine and manganese and a chemical called S-methyl cysteine sulphoxide (SMCO) very high intakes should be avoided as they can lead to haemolytic anaemia and fertility problems. 

Onions, leeks, garlic and Allium species synthesize cysteine sulphoxide derivatives... 

Kusterer J., Keusgen M. Cysteine sulphoxides and volatile sulphur compounds from Allium tripedale. Journal of the Agricultural and Food Chemistry, 58 1129-1137 (2010). 

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