Cysteine adducts

Polyethylene glycol 400 cysteine adducts of a-, -unsaturated aldehydes as dansyl hydrazones stabilization and enhancement dipping solution, 25% in chloroform [268]... 

XU K and thornalley p j (2000) Studies on the mechanism of the inhihition of human leukaemia cell growth hy dietary isothiocyanates and their cysteine adducts in vitro , Biochem Pharmacol, 60 221-31. 

Ethacrynic acid—not a sulfonamide derivative—is a phenoxyacetic acid derivative containing an adjacent ketone and methylene group (Figure 15-7). The methylene group (shaded in figure) forms an adduct with the free sulfhydryl group of cysteine. The cysteine adduct appears to be an active form of the drug. 

D. Noort, A.G. Hulst, L.P.A. De Jong and H.P. Benschop, Alkylation of human serum albumin by sulfur mustard in vitro and in vivo mass spectrometric analysis of a cysteine adduct as a sensitive biomarker of exposure, Chem. Res. Toxicol, 12, 715-721 (1999). 

XH- and 195Pt-NMR investigations have shown that therapeutic nucleophilic agents for cisplatin, such as Na(ddtc) (sodium diethyldithiocarba-mate) and thiourea, can help to remove Pt from certain proteins [35]. The mechanism may be based on the relatively easy reversal of Pt binding to methionine side chains. In contrast, nephrotoxicity, thought to be caused by formation of Pt-cysteine adducts (Pt11 thiolate bonds), cannot be reversed by Na(ddtc) and thiouera. 

Tillian HM, Schauenstein E, Ertl A, et al. 1976. Therapeutic effects of cysteine adducts of alpha, beta-unsaturated aldehydes on Ehrlich ascites tumor of mice. Eur J Cancer 12 989-993. 

The successful identification of cysteine adducts encouraged us to study the reaction of 170 and GSH-cat Fe(III). After careful isolation, an adduct 174, similar to 167, was obtained in 1% yield from the aqueous layer, which was easily rearranged to compound 175 in acidic medium. Thereafter, a similar adduct 176 between GSH and the primary C-radical derived from qinghaosu was isolated and structurally confirmed by NMR and other spectroscopy (Stmcture 5-26). ... 

Wu, W. M. Chen, Y. L. Zhai, Z. L. Xiao, S. H. Wu, Y. L. Study on the mechanism of action of artemether against schistosomes—The identification of cysteine adducts of both carbon-centered free-radicals derived from artemether. Bioorg. Med. Chem. Lett., 2003, 13(10) 1645-1647. 

Blood Albumin adduct, cysteine adduct Digestion with pronase LC-MS/MS Noort et al. (1999, 2004)... 

Recent studies identify a new metabolic pathway for chloropicrin involving a rapid dechlorination to CHCI2NO2 and conversion of glutathione (GSH) to GSSG plus possible adduct formation with thiol proteins. In this newly discovered pathway, chloropicrin is metabolized to thiophosgene, characterized as the cyclic cysteine adduct (raphanusamic acid) in mice urine. The initially formed GS-CCI2NO2 metabolite is proposed to either react further with GSH or is cleaved by cysteine-/l-lyase, ultimately leading to raphanusamic acid, which is excreted. Chloropicrin is an... 

Since MIC is highly reactive, it is not metabolized in the classical sense. Conjugation of MIC with glutathione (GSH) forming an adduct S-(N-methyl-carbamoyl) glutathione, and corresponding cysteine adduct, S-(N-methylcarbamoyl) cysteine appears to represent an important pathway of biotransformation of MIC in the rats exposed to MIC intraper-itoneally. The reaction of MIC with GSH and with cysteine is reversible, and can provide a source of free MIC in the tissues. It is speculated that these carbamate thioester conjugates of MIC may actually contribute to toxic effects of MIC. Similar studies in experimental animals exposed to MIC by the inhalation route have not been reported. 

Zimmerman LJ, Valentine HE, and Valentine WM (2004) Characterization of 5-(N,N-dialkylaminocarbonyl)cysteine adducts and enzyme inhibition produced by thiocarbamate herbicides in the rat. Chemical Research in Toxicology 17 258-267. 

TDG Albumin-cysteine adduct Iranian CW (25) Up to 10 days 1-100 ng/ml (24/25) 330 ng/ml (1/25) = 0.4-1.8 pM Mean in control samples was 5 ng/ml highest 20 ng/ml. TDG was converted to sulphur mustard with concentrated HQ (Wils el al., 1985, 1988) Expressed as concentration of sulphur mustard that induced the same level of adduct on incubation with human blood (Noort et al., 1999)... 

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