Automated Determination of Pharmaceutically and Biologically Active Thiols by Sequential Injection Analysis: A Review

Tzanavaras, Paraskevas D.

doi:10.2174/1875038901003010037

Cited by 6 publications

(2 citation statements)

References 30 publications

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“…Thiols are also one of the most reactive functional groups in the cell, 1 and they protect cells from oxidative injury and toxic metal exposure via addition, substitution, elimination, and oxidation reactions. 2,3 The concentration of R-SH (as a free molecule or in specific compounds) in cells and biological fluids is in fact used as a diagnostic tool for diseases related to oxidative stress in humans and as a diagnostic tool for metal stress in organisms. 2,4−6 Photosynthetic organisms are also known to produce R-SH in high concentrations, either to facilitate metal transport or to reduce metal toxicity.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Organic thiol (R-SH) compounds are important complexing ligands for soft Lewis acids, such as Cd 2+ and Hg 2+ , and the concentration of R-SH can modify the speciation of these metals in natural waters. Thiols are also one of the most reactive functional groups in the cell, and they protect cells from oxidative injury and toxic metal exposure via addition, substitution, elimination, and oxidation reactions. , The concentration of R-SH (as a free molecule or in specific compounds) in cells and biological fluids is in fact used as a diagnostic tool for diseases related to oxidative stress in humans and as a diagnostic tool for metal stress in organisms. ,− Photosynthetic organisms are also known to produce R-SH in high concentrations, either to facilitate metal transport or to reduce metal toxicity . Several types of R-SH compounds are released into natural waters during the life cycle and decomposition of these organisms .…”

Section: Introductionmentioning

confidence: 99%

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Estimation of Reactive Thiol Concentrations in Dissolved Organic Matter and Bacterial Cell Membranes in Aquatic Systems

Joe-Wong

Shoenfelt

Hauser

et al. 2012

Environ. Sci. Technol.

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Organic thiols are highly reactive ligands and play an important role in the speciation of several metals and organic pollutants in the environment. Although small thiols can be isolated and their concentrations can be estimated using chromatographic and derivatization techniques, estimating concentrations of thiols associated with biomacromolecules and humic substances has been difficult. Here we present a fluorescence-spectroscopy-based method for estimating thiol concentrations in biomacromolecules and cell membranes using one of the soluble bromobimanes, monobromo(trimethylammonio)bimane (qBBr). The fluorescence of this molecule increases significantly when it binds to a thiol. The change in the sample fluorescence due to thiols reacting with qBBr is used to determine thiol concentration in a sample. Using this method, small thiols such as cysteine and glutathione can be detected in clean solutions down to ~50 nM without their separation and prior concentration. Thiols associated with dissolved organic matter (DOM) can be detected down to low micromolar concentration, depending on the DOM background fluorescence. The charge on qBBr prevents its rapid diffusion across cell membranes, so qBBr is ideal for estimating thiol concentration at the cell membrane-water interface. This method was successfully used to determine the thiol concentration on the cell envelope of intact Bacillus subtilis to nanomolar concentration without any special sample preparation. Among the chemical species tested for potential interferences (other reduced sulfides methionine and cystine, carboxylate, salt (MgCl(2))), carboxylates significantly influenced the absolute fluorescence signal of the thiol-qBBr complex. However, this does not affect the detection of thiols in heterogeneous mixtures using the presented method.

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Section: ■ Introductionmentioning

confidence: 99%