Taurine: analysis

Since then, there have been a number of reversed-phase separations employing precolumn derivatization. Interestingly, fluorescamine (not frequently employed for RP-HPLC of amino acids with precolumn reaction) has been reported for taurine analysis in milk (197) and human plasma (198). Precolumn derivatization with OPA/2-mercaptoethanol has been reported for the analysis of infant formula and human breast milk (199). Although not the principal focus of the study, Carratu et al. (200) report taurine values in parenteral solutions as determined by FMOC. In an excellent article, Woollard and Indyk (201) report the dansylation of taurine for its determination in a wide variety of dairy-related products. Subsequently, the same authors report the results of a large collaborative study (202) for the determination of taurine (again, by dansylation) in milk and infant formula. This study afforded an overall interlaboratory RSD of 7.0% and established a lower limit for determination at 5 mg taurine per 100 g of product. 

DC Woollard, HE Indyk. Taurine analysis in milk and infant formulae by liquid chromatography collaborative study. J Assoc Off Anal Chem Int 80 860-865, 1997. 

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

Larsson, O. M., Griffiths, R., Allen, I. C., and Schousboe, A. (1986) Mutual inhibition kinetic analysis of gamma-aminobutyric acid, taurine and beta-alanine high-affinity transport into neurons, and astrocytes evidence for similarity between the taurine and beta-ala-nine carriers in both cell types. J. Neurochem. 47,426 132. 

A method for analysis of A-nitroso-A-alkylureas (288b) has been developed by forming fluorescent derivatives with sodium sulfide, taurine (77) and o-phthalaldehyde (73)... 

Ion pair extraction has also been used to extract polar analytes in bioanalytical procedures. Figure 15.2 exemplifies the determination of the amino acid taurine by gas chromatography-mass spectrometry (GC-MS) this figure also illustrates a useful property of amines (and phenols), which is that they will react more rapidly than water with an acylating reagent in an aqueous environment thus improving their organosolubility. After acylation and ion pair extraction with tetrabutyl ammonium sulphate the taurine is converted to an amide prior to analysis by GC-MS. 

The possibility of defining serum BA composition was also assessed in the reported study. Analysis of the free fraction before and after treatment with ampicillin of a patient with PBC was performed (Fig. 5.4.9). The antibiotics are used in the therapy of cholestatic syndrome, but some studies have been carried out to define their use. This kind of therapy inhibits the production of secondary BAs (DCA and LCA) and the deconjugation of taurine and glycine conjugates. Consequently, an... 

This method allows a quantitative analysis of BAs present in biological fluids (free, and glycine- and taurine-conjugated forms) in a single chromatographic run, performed with an HPLC mass spectrometric system equipped with an electrospray interface [33]. 

Melemeleones A and B (320 and 321) possess a 4,9-friedodrimane sesquiterpene array linked to a quinone bearing a taurine and they are structurally related to avarol. Compounds 320 and 321 were isolated from the sponge Dysidea sp. and identified by analysis of their spectroscopic data. Compound 321 showed a moderate inhibitory activity against the pp60v src protein Tyrosine Kinase with an IC50 of 28 pM [236]. 

Compound 325 is the taurine derivative of clathridine (a very stable zinc complex obtained from Clathrina clathrus) [240] and was isolated from the sponge Leucetta microrhaphis. Compound 325 is (9E)-clathridine 9-Ar-(2-sulfoethyl)imine and its structure was deduced by spectroscopic and chemical analysis, and confirmed by single crystal X-ray analysis. The taurine residue appears to sterically inhibit the formation of the zinc complex [241],... 

This final section of the chapter will be composed primarily of a tabulated literature survey categorizing references based on the type of sample analyzed and the chemistries employed for separation/detection. However, because of its unique nature (and because this topic didn t fit well into any other section of the chapter), special attention will be paid to the analysis for taurine and its application in nutritional products. 

B Saidi, JJ Warthesen. Analysis and heat stability of taurine in milk. J Dairy Sci 73 1700-1706, 1990. 

Identification and structural characterization of an unknown class of substrates for FAAH. (A) By high-resolution mass spectrometry, the high-accuracy mass measurements of a compound of this class gives an exact mass of 446.3310 that corresponds to a molecular formula of C24H48N04S. (B) By MS/MS analysis, the structure of this compound is assigned as the C24 0 fatty acyl amide of taurine (NAT). Reproduced from Saghatelian A., Trauger S.A., Want E.J., Hawkins E.G., Siuzdak G. and Cravatt B.F., Biochemistry, 43,14332-14339, 2004, with permission. 

Mustard exposure causes depletion of ATP in cells. Better outcomes after exposure have been demonstrated when mitochondrial substrates were provided to offset this depletion. CEES-exposed rabbit corneas have been treated after exposure with a mix of taurine, pyruvate, a-keto glu-tarate, and pantothenic acid. Analysis showed reduced necrosis of the cornea. Electron microscopic and other analyses showed protection against membrane damage and oxidative damage (Varma et al, 1998a, b). 

Due to an increased interest in analysis of physiological samples, we wanted to establish analyzer methods which would allow us to choose between our standard protocol for protein and peptide hydrolysates and a separate protocol for an expanded number of amino acids, to include the most important free amino acids found in physiological samples. A study of common analysis requirements in our facility indicated that only a limited number of the possible free physiological amino acids is needed for most unknown samples. These additional amino acids of interest are a-amino butyric acid, citrulline, y-amino butyric acid (GABA), hydroxyproline, hydroxylysine, ornithine, taurine, and tryptophan. Other amino acids of interest to us are phosphoserine, phosphothreonine, phosphotyrosine and carboxy-amino acids since they are released from glycoprotein or glycopeptide hydrolysates. 

Postcolumn labeling is a characteristic feature of carbohydrate analysis in which no direct physical methods are available for sensitive detection. Many labeling methods have hitherto been developed. The methods with phenol in sulfuric acid [16], orcinol in sulfuric acid [17], anthrone in sulfuric acid [18], tetrazolium blue in alkali [19], copper(II)-2-2 -bicin-chonitate [20], and 2-cyanoacetamide [21] are used for photometric detection. The methods with 2-cyanoacetamide [6], ethylenediamine [22], ethanolamine [23], taurine [24], and arginine [25] are used for fluorimetric detection. Some labeling methods for electrochemical detection were reported by Honda and Suzuki in 1984 [26,27],... 

LC/MS has had a strong influence upon pharmaceutical chemistry for the analysis of both highly polar metabolites and their precursors, as described in the second section of this book. The technique has been used for the analysis of polypeptides and a variety of intractable pharmaceuticals such as tetracycline, -lactams, and polyether antibiotics. The structures of highly polar drug metabolites formed in vivo— including sulfate esters, glucuronides, taurine, and camotine... 

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