Thiols identification

Ellis MK, Hill S, Foster PMD. 1992. Reactions of nitrosonitrobenzenes with biological thiols identification and reactivity of glutathion-S-yl conjugates. Chem-Biol Interactions 82 151-163. 

Redox regulation of surface protein thiols identification of integrin alpha-4 as a molecular target by using redox proteomics. Proc. Natl. Acad. Sci. USA 100, 14737-14741. 

As shown in Fig. 1.21, a series of di- and tri-thiols were mixed under conditions suitahle for disulfide formation and exchange, and allowed to evolve in the presence of an ephedrine template. HPLC-MS analysis of the library mixture after equilihrium had been reached allowed the identification of two heterotetrameric receptors with high (K = ICfi) affinity for ephedrine in borate buffer, although it is not clear whether these were in fact the best binders in the library. 

In a recent example metalloporphyrins are used as the sensing dyes for a wide variety of odorants, including alcohols, amines, arenes, ethers, halocarbons, ketones, phosphines, thioethers and thiols. An array of four different metalloporphyrins are placed on a substrate and exposed to the vapours for 30 s. The various vapour molecules coordinate onto the central metal atoms of the porphyrins, causing them to change colour and producing a unique four-colour array. The resulting colour array is compared with a library of known chemicals or mixtures and identification is achieved. 

A summary of the work on the identification of sulfur compounds in crude oils has been given recently by Ball, Rail, Waddington, and Smith (31), who list the sulfur compounds isolated from petroleum by earlier investigators and, in addition, give several new compounds which have recently been isolated from a Wasson, Tex., crude petroleum by the API Research Project 48. Birch and Norris (5) isolated a substantial number of the thiol (mercaptan) type of sulfur compounds from an Iranian crude petroleum. 

In collaboration with Lang, Winter, Williams, and Roder have also studied the Mossbauer spectrum of the Fe(III) hemoglobin thiol-complexes. The Mossbauer spectra of these complexes are rather different from those of all other low-spin complexes. Thus, should it prove possible to substitute 57Fe in P-450, Mossbauer spectroscopy of the protein could lead to a relatively safe identification of the Fe(III) heme/thiol link. 

J-20) were identified as having the potential to deliver improved potency over the lead compound 3. These candidates were then used as the basis for a traditional medicinal chemistry investigation and optimization (Scheme 7.5). The overall outcome for this study was the identification of four novel thiol compounds with K 6-17 xM, 10-30-fold more potent than the lead compound 3 with a K of 185 xM. 

The highest enantioselectivity (up to >99%) yet achieved in the addition of S-nucleophiles to enones was reported in 2002 by Deng et al. [59]. By systematic screening of monomeric and dimeric cinchona alkaloid derivatives they identified the dihydroquinidine-pyrimidine conjugate (DHQD PYR (72, Scheme 4.35) as the most effective catalyst. This material is frequently used in the Sharpless asymmetric dihydroxylation and is commercially available. Screening of several aromatic thiols resulted in the identification of 2-thionaphthol as the nucleophile giving best yields and enantioselectivity. Examples for the (DHQD PYR-catalyzed addition of 2-thionaphthol to enones are summarized in Scheme 4.35. 

Sarrazin, E., Shinkaruk, S., Tominaga, T., Bennetau, B., Frerot, E., and Dubourdieu, D. (2007b). Odorous impact of volatile thiols on the aroma of young botrytized sweet wines Identification and quantification of new sulfanyl alcohols. /. Agric. Food Chem. 55,1437-1444. 

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