Cysteine formula

Methionine and Cysteine Metabolism. Methyl groups play an important role in the biosynthesis of many substances, and methionine has turned out to be the methyl donor par excellence. Active methyl arises directly out of methionine and ATP it is a sulfonium compound (formula in Chapt. VI-5). We shall return to the active methyl group on occasion (cf. also Chapt. VI-5, XIII-2, XX-5), but now will discuss the demethylated methionine. Its name is homocysteine, because its carbon chain is longer than that of cysteine by one CH2 group. It can provide the sulfur for cysteine by condensing with serine the resultant thioether (cystathionine) breaks into homoserine and cysteine (formulas below). 

Consider the cysteine molecule shown in Table 23.3. Write structural formulas for... 

Cycloalkane A saturated hydrocarbon containing a closed ring. General formula = C H2 , 584-585 Cyclopentane, 584 Cysteine, 622t... 

CASRN 133-06-2 molecular formula C9H8CI3NO2S3 FW 300.57 Biological. In water, captan reacted with the fungicide i-cysteine forming a compound with an absorption maximum of 272 mm which was identified as 2-thiazolidinethione-4-carboxylic acid. In addition, tetrahydrophthalimide also formed (Lukens and Sisler, 1958). 

Baumann next found that cystine, on reduction with zinc and hydrochloric acid, was converted into a new base, which he called cysteine this gave the same products on decomposition as cystine, into which it was easily reconverted by oxidation. He therefore recognised that these compounds were related to each other, as a mercaptan is to a disulphide consequently the formula... 

The actual formation of pyruvic acid from various mercapturic acids upon which these formulae for cysteine and cystine were founded, was only shown later by Baumann s pupils, Konigs, Brenzinger and Schmitz, and in conjunction with Suter s observation that a-thiolactic acid was formed by the hydrolysis of horn, this formula for cystine was accepted. The results obtained, however, scarcely justified this formula as pointed out by Friedmann in 1902, who showed conclusively that the cystine, obtained from proteins, had not this constitution. 

Therapeutic Function Antirheumatic, Immunomodulator Chemical Name L-Cysteine, N-(2-mercapto-2-methyl-l-oxopropyl)-Common Name Bucillamine Tiobutarit Structural Formula ... 

Among the most abundant components of the cysteine + ribose + lecithin reaction mixture were the 2-pentylpyridine and two long-chain alkyl substituted thiophenes 2-pentyl- and 2-hexylthiophenes [31,32], together with a related compound with molecular formula and... 

We have devised a DvMF model by substituting a methyl group for cysteine (Cys) in the structural formula shown in Figure 9-15, where SI is the bridging atom between the Fe atom and Ni atom, S2 is one of the bridging S atomsof the cysteine amino acids and S3 is one of the S atoms of the cysteine amino acids coordinated to the Ni atom only. We then optimized the structure. The optimized atomic distances and... 

Accordingly, as the first step, the interaction of qinghaosu and cysteine in the presence of a catalytic amount of Fe(lFlll) was studied. From the reaction mixture, a water-soluble compound was isolated. This compound could be visualized with ninhydrin on TLC, and it showed a formula of C16H27NO6S H2O. Treatment of this compound with acetic anhydride yielded a cyclic thioether 165, which in turn undoubtedly showed the formation of adduct 166 of 1 and cysteine through a a bond between C-3 and sulfur. A stable adduct 167 of cysteine and 170 was then isolated in 33% yield with the same reaction protocol. As mentioned, both adducts of cysteine with primary and secondary free radical derived from arte-mether were also identified recently, albeit in low yield (Structure 5-25). More... 

Shatsky F, McFeely EJ, Takahashi D. A table for estimating calcium and phosphorus compatibility in parenteral nutrition formulas that contain trophamine plus cysteine. Hosp Pharm 1995 30 690-692, 793. 

Cystine is an amino acid formed from the oxidation of two cysteine molecules to form a disulfide bond. The molecular formula of cystine is C6H12O4N2S2. Draw the structural formula of cystine. Hint For the structure of cysteine, see page 385.)... 

This structure, although consistent with many facts, did not explain the peculiar properties of the A-terminal isoleucine and the negative test for —SH groups. Further experiments led to the conclusion that a thiazoline ring is formed between isoleucine and cysteine this was later proved to be correct. All these results led to the formula for bacitracin A which is now generally accepted - Figure 1.4). 

Fig. (6). Reaction mechanism observed during reaction of HEL and L-cysteine. The 3D-model shows the transition structure obtained by energy minimisation of the cysteine thiolate anion and a molecule of helenalin using the semiempirical AMI hamiltonian. The surface representation of the highest occupied molecular orbital (HOMO) shows that this structure corresponds to the middle formula (above) in which the major part of the jt-electron density is transferred to the 11-.12 bond. Note the proximity of the NH3T to the lactone carbonyl oxygen.

Sulfonic acids represented by the general formula RS03H are found in nature. Examples are the amino acids taurine (1) and cysteinic acid (2)1. 

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