Isothiocyanate, determination

The urinary yield of isothiocyanates depends on the form in which the dose is given. The urinary yield of total isothiocyanates (determined using the dithiol cyclo condensation method) from an oral dose of sulphoraphane was 80% but for the parent glucosinolate... 

Edman degradation (Section 27 13) Method for determining the N terminal amino acid of a peptide or protein It in volves treating the material with phenyl isothiocyanate (CgH5N=C=S) cleaving with acid and then identifying the phenylthiohydantoin (PTH derivative) produced Elastomer (Section 10 11) A synthetic polymer that possesses elasticity... 

Determination of ethyleneamines in air can be accomplished by absorbing the amines on NITC (1-naphthyl isothiocyanate) treated XAD-2 resin, then desorbing the derivative from the treated tubes and quantifying the amount using high performance Hquid chromatography (hplc). Sensitivity is reported as 0.37 and 0.016 mg/m for EDA and DETA, respectively, pet sample (153,154). 

E. A. Hogendoorn, C. Verscliraagen, U. A. Th Brinkman and van P. Zoonen Coupled column liquid chr omatography for the tr ace determination of polar pesticides in water using dhect large-volume injection method development strategy applied to methyl isothiocyanate , Awn/. Chim. Acm 268 205-215 (1992). 

Calibration. Many approaches have been used to calibrate flow cytometric measurements. Including the comparison of flow and nonflow techniques (radiolabels, spectrofluorometry). In recent years, commercial standards have been introduced which are calibrated in fluorescein equivalents/particle (e.g., 3,000 or 500,000). With labeled ligands, calibration requires determining the relative quantum yield of the ligand compared to pure fluorescein and using the standards to analyze the amount bound on cells. Our ligands (fluorescein isothiocyanate derivatives) are typically 50% as fluorescent as fluorescein. 

Many in vitro studies have been undertaken to explore the relative effectiveness of isothiocyanates, and associated compounds, as inhibitors of cell growth and inducers of apoptosis in cell lines, and some of these are summarised in Table 4.2. Clonal survival studies are often used to determine whether isothiocyanates inhibit initial cell anchorage and subsequent growth of sparsely seeded cells. However, differences in cell number following challenge with the isothiocyanate could be due either to decreased cell division or increased cell loss, and the authors of some in vitro studies have failed to recognise this. Other studies have, however, considered the interacting... 

ZHANG Y, WADE K L, PRESTERA T and TALALAY p (1996) Quantitative determination of isothiocyanates, dithiocarbamates, carbon disulfide, and related thiocarbonyl compounds by cyclocondensation with 1,2-benzenedithioT, Anal Biochem, 239 160-67. 

YE L, DINKOVA-KOSTOVA A T, WADE K L, ZHANG Y, SHAPIRO T A and TALALAY P (2002) Quantitative determination of dithiocarbamates in human plasma, serum, erythrocytes and urine pharmacokinetics of broccoli sprout isothiocyanates in humans , Clin ChimActa, 316 43-53. 

Albin, D. M., Wubben, J. E., and Gabert, V. M., Effect of hydrolysis time on the determination of amino acids in samples of soybean products with ion-exchange chromatography or precolumn derivatization with phenyl isothiocyanate,. Agr. Food Chem., 48, 1684, 2000. 

Epipolasin-B (61), mp 92 °C, was one of two isothiocyanates obtained from the sponge Epipolasis kushimotogensis. Neither the isonitrile nor formamido analog were found with the isothiocyanate. Instead, the thiourea adduct of /J-phenylethylamine was isolated along with another isothiocyanate-thiourea pair [51]. The absolute configuration of 61 was determined by appropriate... 

The preparation of 5-chloro-l,2,4-thiadiazol-2-ium chlorides 95 by treatment of formimidoyl isothiocyanates 94 with a twofold excess of methanesulfenyl chloride has been reported in an unusual variation of a type C synthesis. These salts show interesting chemical behavior toward several nitrogen and carbon nucleophiles. The nature of the N-substituent determines the stability of the salt 95. When the substitutent on nitrogen is /-butyl, the salt 95 decomposes readily in solution to give the 5-chloro-l,2,4-thiadiazole 96 (Scheme 10) <2003HAC95>. 

Consequently, the research work of Hara s group continued focusing on the improvement of protein determination using CE combined with online CL detection. By replacing EY by the Rhodamine B isothiocyanate (RITC) dye in the binary complexes formed with the proteins BSA or human serum albumin (HSA) and using a different imidazole buffer solution of pH 6, the sensitivity was increased [72], However, best detection limits for these determinations were found employing the tetramethylrhodamine isothiocyanate isomer (TRITC) dye, left for 4 h with a standard solution of BSA in acetonitrile followed by introduction into the capillary. For BSA, a detection limit of 6 nM was reached [73],... 

Amino acids derivatized with 9-fluorenylmethyl chloroformate (90) were separated by CE and determined by LIF with a pulsed laser LOD 0.5 nM (SNR 2)322. A sensitive technique for amino acids is capillary zone electrophoresis (CZE) combined with LIF of their fluorescein isothiocyanate (133) derivatives. Not all amino acids give good resolution. LOD for proline and arginine were 0.3 and 0.5 nM, respectively323. 

The interpretation of conductance data is complicated by the labile nature of the lanthanide complexes in solution which results in ligand exchange and dissociation reactions. It is difficult to understand the nature of the complex species present in solution. A combination of conductance data and molecular weight determination may be useful in determining the coordination number and structure of the complexes in solution. However, due to the poor solubility of lanthanide complexes in suitable solvents, molecular weight data have been obtained for only a few complexes. The dissociative reactions of lanthanide complexes in solution are well illustrated by the TPPO complexes of lanthanide isothiocyanates (202). In chloroform solution, the dissociation... 

A more useful procedure, in that it allows sequential determination of the A-terminal amino acids in a peptide, is the Edman degradation. This process removes the A-terminal amino acid, but leaves the rest of the chain intact, so allowing further reactions to be applied. The reagent used here is phenyl isothiocyanate. 

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