Taurine preparation

The purity of the taurine prepared by this method was established by analysis. 

CJH4O5, H02CCH(0H)C02H. Colourless crystals with IH O lost at 60 C. M.p. IhO C (decomp.). Prepared by heating dinitrotartaric acid in aqueous alcohol, taurine, aminoethylsulpbonic acid, C2H7NO3S, NHj CHj CH SOjH. Crystallizes in columns, decomposing at 317 C. In combination with cholic acid it forms one of the bile acids. It is formed in the liver from cysteine. 

Ethyleneimine reacts rapidly with sulfurous acid to give taurine [107-35-7] in high yield, a reaction of importance not only for the preparation of this amino sulfonic acid but also for the decontamination of ethyleneimine solutions (130). 

This product may contain as much as 2 to 5 per cent of sodium bromide, but it is pure enough for the preparation of taurine (p. 98). A very pure product can be obtaified by a second crystallization from alcohol. 

Taurine is generally prepared from ox bile1 or the large muscle of the abalone.2 It has been synthesized from isethionic add through chloroethanesulfonic acid followed by the action of aqueous ammonia 3 from ethyleneimine and sulfur dioxide 4 from 2-mercaptothiazoline by oxidation with bromine water 5 from bromoethylamine and ammonium sulfite 6 and from acetaldehyde by a complex set of reactions involving sulfonation, formation of the aldehyde ammonia and the imido sulfonic add and finally reduction.7 The method given in the procedure has recently appeared in the literature.8 9... 

The first studies of specificity were carried out using cholate, the glycine and taurine conjugates and taurine conjugates of the dihydroxy bile acids cheno-deoxycholate and ursodeoxycholate. Kramer and colleagues prepared plasma membrane vesicles from rat liver and compared bile-acid transport with values from CHO cells stably expressing NTCP. This work established that transport by the liver enzyme was maximal when 2 hydroxyls were present,... 

Salty taste enhancing preparations or compounds besides KCl were described. For example, a mixture of certain amino acids based on L-lysine were used to increase the saltiness of a NaCl-reduced preparation [34] y-aminobutyric acid (4) was also used as a salty taste enhancer [35]. Some dipeptides such as N-l-ornithyl taurine hydrochloride or N-L-lysinyl taurine hydrochloride were described as very salty with a clean salt taste [36]. Additionally, choline chloride was suggested as a salt enhancer [37]. 

Pentz et al. (P5) estimate taurine with fluorodinitrobenzene in urine passed through Dowex 50 H+ columns, but there are doubts as to whether this procedure is really specific for taurine (B38). Dent et al. have compared results obtained for the estimation of sulfur-containing amino acids in urine of cystinuric patients, by polarographic and microbiological methods (D18, D19). Hier (H12) and Schreier and Pliickthun (S10, Sll) have published data on amino acid excretion as determined microbiologically. Enzymatic methods have been used with success in the case of histidine in urine with specific decarboxylase preparations (S23). 

Chemistry and general properties. Taurine is amino ethane sulphonic acid, and although it is possible to prepare true acyl taurates, superior performance is obtained by using N-methyl taurine (see Figure 4.27). Taurate in this section is used to mean the N-methyl derivative, as is common in industry. 

Valproyltaurinamide derivatives, (II), prepared by amidation of 2-propyl-pentanoic acid (valproic acid) using 2-aminoethanesulfonic acid (taurine) previously prepared by the authors (2) was effective as an antiseizure medicament. 

Stock solutions (2.5 mM) of a-aminobutyric acid (Aab), y-aminobutyric acid (Gaba), Asn, cysteic acid (Cya), Gin, Hyp, Hyl, Orn, taurine (Tau), and Trp were prepared in water. Mixture I consisted of 40 pi each of Hyl, Hyp and Pierce H mixed with 880 pi of water (0.1 mM per amino acid). Forty pi of each stock... 

The 2-aminoethanesulfonates (i.e., taurines) are the prepared reaction of ammonia or V- or 2""-amines with metal 2-haloalkanesulfonate, vinylsulfonate, or hydro-xyethanesulfonate salts under alkaline conditions. The aminoethanesulfonate salts are then converted to the zwitterionic acids by cation exchange or acidification. 3-Aminopropanesulfonic acids are directly prepared by the reaction of propanesultone with the amine. 

The formation of an amide bond by organic chemical methods Is usually accomplished by reacting the acid halogenlde and the amino acid unless the acid substrate contains other reactive groups. The acid chloride Is prepared directly with thlonyl chloride (244) or Indirectly via the formation of a mixed anhydride by use of another acid halogenlde (245,246). Isotoplcally labeled [(2,4-Dlchlorophenoxy)acetyl]valine was synthesized by a DCC catalyzed reaction between the acid and valine (247). A few examples of synthetic amino acid conjugates of xenobiotics are shown In Table X. Several taurine conjugates of both alkanolc and benzylic acids have been synthesized and their physical properties determined by Idle et al. (2 ). 

Netobimin (84) has been prepared by treating a solution of N-(methoxycar-bonyl)-S-methyl-N -[2-nitro-5-(propylthio)phenyl]isothiourea (83) with taurine (H2N-CH2CH2SOJH) and NaOH [66-68] (Scheme 11). 

Unlike enzymatic or radioimmunoassay methods, GLC requires lengthy sample preparation before bile acid concentrations can be determined. In the case of serum, bile acids must be extracted (see Section 6.1) and hydrolysis carried out to remove glycine and taurine, and also sul te groups, if they are likely to be present (see Section 6.2). The free bile acids are then converted to volatile derivatives. 

This paper (S4) compares the two silylating reagents bis (trimethyl-silyl) acetamide (BSA), first described by Klebe et ad. (K6), and bis-(trimethylsilyl) trifluoroacetamide (BSTFA), for the preparation of volatile trimethylsilyl (TMS) derivatives of 12 sulfur-containing amino acids. BSTFA was recommended as the reagent of choice for taurine, cysteic acid, homocystine, djenkolic acid, ethionine, methionine sulfone, L-2-thiolhistidine, cysteine, and cystine. For S-methyl-L-cysteine, methionine sulfoxide, and methionine, BSA was used as silylating reagent. 

Another example published by Whitesides and co-workers is the preparation of diphosphine 8 using sodium taurinate as the sulfonate donor. Diphosphine 8 and its metal complexes appeared to be highly water-soluble, with a concentration in aqueous solution of 0.3 M (pH 7.0, 25 °C) [13]. In the same way, several other diphosphines were synthesized. 

A series of cholic amides 84, 87 and 90 are synthesized from cholic acids 82, 85 and 88 and a-amino esters 83, 86 and 89 using DEPC.32 Condensation reaction of muricholic acid (82) with taurine or glycine methyl ester (83) provides amide 84.33 A novel amide 87 is prepared by coupling of cholic acid 85 to amino acid ester 86, using DEPC as a coupling agent.34... 

Chemical Separation of oxalic acid from glyoxal,44 separation of sodium formate from pentaerythritol,45 preparation of aminoethane sulfonic acid (taurine),46 production of acids and alkalis from neutral salts by water-splitting using a bipolar ion exchange membrane,47 production of pure water by electro-deionization,48 utilization of double decomposition of salt49... 

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