Cysteamine

Formaldehyde from cigarette smoke is collected by trapping the smoke in a 1-L separatory funnel and extracting into an aqueous solution. To aid in its detection, cysteamine is included in the aqueous extracting solution, leading to the formation of a thiazolidine derivative. Samples are analyzed... 

Reaction with Sulfur Nucleophiles, Because sulfai is highly nucleophilic, reactions of aziridines with sulfur nucleophiles generally proceed rapidly (111) and with good yields. The reaction of hydrogen sulfide [7783-06S-J with ethyleneimine yields cysteamine [60-23-1] (2-mercaptoethylamine) or bis(2-aminoethyl)sulfide [871-76-1] (2,112) depending on the molar ratio of the reactants. The use of NaHS for the synthesis of cysteamine has also been described (113). 

Cystamine dihydrochloride, S,5-(L,L)-Cystathionine, Cysteamine, Cysteamine hydrochloride, ( )-Cysteic acid, S-Cysteic acid (H2O), L-Cysteine hydrochloride (H2O), ( )-Cysteine hydrochloride and L-Cystine, Cytidine, see entries in Chapter 6. 

Another entry into the anti ulcer sweepstakes is etinfidine (50). It is synthesized by displacement of halide from 4-chloromethyl-5-methylimidazole (4 ) with substituted thiol The latter is itself made from thiourea analogue by an addition-elimination reaction with cysteamine 52. °... 

Potassium hydroxide Cysteamine Carbon disulfide Dimethyl sulfate Sodium Ammonia Cyanamide Methylamine ... 

Cyclopropylmethoxy)ethyil phenol Betaxolol HCI Cysteamine Cimetide Cysteine... 

The chloroacetylurea derivative (A = C1CH2) obtained from the above addition (Eq. 1), on treatment first with thioacetic acid and Et3N and then with cysteamine, afforded the corresponding thiol (A = HSCH2) (Eq. 3)l5). 

The correct pairing of half-cystine residues is shown to be dependent upon specific noncovalent bonds 17). With this finding in mind, oxidation of a pair of associating thiols (7 and 2) was chosen as a model reaction. Thiol 7 has the same group as cysteine side chain (HSCH2), 2 being a derivative of cysteamine. 

The strained bicyclic carbapenem framework of thienamycin is the host of three contiguous stereocenters and several heteroatoms (Scheme 1). Removal of the cysteamine side chain affixed to C-2 furnishes /J-keto ester 2 as a possible precursor. The intermolecular attack upon the keto function in 2 by a suitable thiol nucleophile could result in the formation of the natural product after dehydration of the initial tetrahedral adduct. In a most interesting and productive retrosynthetic maneuver, intermediate 2 could be traced in one step to a-diazo keto ester 4. It is important to recognize that diazo compounds, such as 4, are viable precursors to electron-deficient carbenes. In the synthetic direction, transition metal catalyzed decomposition of diazo keto ester 4 could conceivably furnish electron-deficient carbene 3 the intermediacy of 3 is expected to be brief, for it should readily insert into the proximal N-H bond to... 

Pantothenic acid is an essential component of coenzyme A (CoA) (Fig. 2) and - as pantetheine - of fatty acid synthase. The HS-group of cysteamine is... 

Relatively few reports have been published subsequently on the use of these reagents. Hope and coworkers99 have used sodium in liquid ammonia to cleave the benzyl sulphonyl derivatives of cysteamine, L-cysteine and L-homocysteine to prepare the corresponding sulphinic acids, as in equation (42). 

The condensation reaction between the triisobutylaluminium complex of cysteamine HCl and a variety of carboxylic esters affords thiazoUnes in good yields. When this method is applied to chiral a-aminoesters, a-aminothiazoUne s are obtained in high optical purity <96TL2935>. 

If the injected acid itself contains iron (III), a precipitation of the asphaltic products can occur when it comes in contact with certain crude oils. This leads to practically irreversible damage of the zone treated. The amount of precipitate generally increases with the strength and concentration of the acid. Certain organic sulfur compounds, such as ammonium thioglycolate, mercaptoethanol, cysteamine, thioglycerol, cysteine, and thiolactic acid [581], can reduce the iron (HI). 

A disadvantage of the glutaraldehyde condensation method is that dimers of the hapten and polymers of carrier protein may also form. To overcome this problem, the reaction time is limited to 2-3 h, or an excess of an amine-containing compound, e.g., lysine or cysteamine hydrochloride, is added. A two-step approach also minimizes dimerization. ... 

With simple Hg thiolates the structures of bis(ethanethiolato)mercury Hg(SEt)2321 and of the cysteamine complex [Hg S(CH2)2NH3 2]Cl2322 have reference character, as only weak or no secondary bonds are present, and therefore the central S—Hg—S entities can be considered to be unperturbed. In mercury bis(tri-t-butoxysilanethiolate) Hg[SSi(o-t-Bu)3], with a strictly linear S—Hg—S unit, two weak intramolecular O II g interactions obviously do not affect the bonding in this unit.323... 

Distribution. Lead in blood partitions between plasma and red blood cells, with the larger fraction (90-99%) associated with red blood cells (Cake et al. 1996 DeSilva 1981 Everson and Patterson 1980 Manton and Cook 1984 Ong and Lee 1980a). Lead in plasma binds to albumin and y -globulins (Ong and Lee 1980a). The fraction that is not bound to protein exists largely as complexes with low molecular weight sulfhydryl compounds these may include cysteine, homocysteine, and cysteamine (Al-Modhefer et al. 1991). Approximately 75% was bound to protein when whole human blood was incubated with 50 ig/dL lead (as lead chloride) approximately 90% of the bound lead was associated with albumin (Ong and Lee 1980a). However, the fraction of lead in plasma bound to protein would be expected to vary with the plasma lead concentration. 

The amino acid complexes [TcNCl(L)(PPh3)] (HL=L-cysteine, L-cysteine ethyl ester, cysteamine) have been prepared from [TcNC PPlfj ] or ASPI14 [TcNCU]/PPh3 [88]. The crystal structure of the L-cysteine ethyl ester complex 21 shows a Tc=N bond length of 1.605(3) A and the Tc atom displaced by 0.594(1) A above the square basal plane [88]. Other structurally characterized examples are the square pyramidal 22 with ONSP coordination and Tc=N 1.611(3) A [81], and 23 with NSPC1 coordination and Tc=N 1.615(7) A [89],... 

Many substances which are necessary (and even essential) for life functions contain sulphur for example, the amino acids cysteine and methionine, the tripeptide glutathione or coenzyme A (CoA), with the latter containing the SH group of cys-teamine as the terminal functional group. CoA acts as a coenzyme in all important biochemical acylations. The cysteamine SH group bonds to carboxylic acids to give thioesters ... 

Keefe et al. (1995) from Stanley Miller s laboratory reported a possible prebiotic synthesis of pantetheine, the part of the CoA molecule without its ADP moiety. They were able to synthesize the CoA precursor from P-alanine, pantoyllactone and cysteamine. This condensation requires concentration of the reaction mixture the warm lagoon theory is required here in order to achieve prebiotic conditions ... 

Michota A., Kudelski A., Bukowska J., Chemisorption of cysteamine on silver studied hy surface- enhanced Raman scattering, Langmuir 2000 16 10236-10242. 

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