Automated tagging of pharmaceutically active thiols under flow conditions using monobromobimane

Tzanavaras, Paraskevas D.; Karakosta, Theano D.

doi:10.1016/j.jpba.2010.11.006

Cited by 8 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…16−20 Detection of R-SH can be conducted using this derivatization method; however, the reaction between the derivatizing reagent and R-SH must be completed before the sample is damaged by light or oxidation. 20 Furthermore, the derivatizing reagents may not be suitable for all samples because of their size or polarity; thus, this method works for only certain types of samples. 21 Some of the common derivatizing agents are Ellman's reagent (DTNB; 5,5′-dithiobis-(2-nitrobenzoic acid)) and DTNP (2,2′dithiobis(5-nitropyridine)), which are used in detecting R-SH in proteins and in natural waters.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Another commonly employed method for R-SH detection involves extraction, separation, and derivatization of R-SH with a thiol-specific compound followed by examination using UV/visible or fluorescence spectroscopy. High-pressure liquid chromatography is also used to further improve the detection of derivatized R-SH molecules. − Detection of R-SH can be conducted using this derivatization method; however, the reaction between the derivatizing reagent and R-SH must be completed before the sample is damaged by light or oxidation . Furthermore, the derivatizing reagents may not be suitable for all samples because of their size or polarity; thus, this method works for only certain types of samples .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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.

View full text Add to dashboard Cite

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.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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.

View full text Add to dashboard Cite

show abstract

“…The placebo mixture used in accuracy and selectivity studies consisted of representative pharmaceutical grade excipients and was prepared at a nominal concentration of 10 mg mL −1 according to previously published protocols [20].…”

Section: Methodsmentioning

confidence: 99%

Automated Stopped-Flow Fluorimetric Sensor for Biologically Active Adamantane Derivatives Based on Zone Fluidics

2019

Self Cite

View full text Add to dashboard Cite

A zone-fluidics (ZF) based automated fluorimetric sensor for the determination of pharmaceutically active adamantine derivatives, i.e., amantadine (AMA), memantine (MEM) and rimantadine (RIM) is reported. Discrete zones of the analytes and reagents (o-phthalaldehyde and N-acetylcysteine) mix and react under stopped-flow conditions to yield fluorescent iso-indole derivatives (λex/ λem = 340/455 nm). The proposed ZF sensor was developed and validated to prove suitable for quality control tests (assay and content uniformity) of commercially available formulations purchased from the Greek market (EU licensed) and from non-EU web-pharmacies at a sampling rate of 16 h−1. Interestingly, a formulation obtained through the internet and produced in a third—non-EU—country (AMA capsules, 100 mg per cap), was found to be out of specifications (mean assay of 85.3%); a validated HPLC method was also applied for confirmatory purposes.

show abstract

“…Additionally, they are an important group of compounds due to their unique role in medicine, food, pharmaceutical and aroma industries [6][7][8]. Together, these characteristics have led to considerable interest in thiolic compounds such as cysteine (CySH) and glutathione (GSH) which have critical functions in physiological processes in a variety of living organisms, ranging from microbes to humans [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Determination of 3-mercaptopropionic acid by HPLC: A sensitive method for environmental applications

Salgado

Visnevschi-Necrasov

Kiene

et al. 2015

Journal of Chromatography B

View full text Add to dashboard Cite

The organic sulfur compound 3-mercaptopropionic acid (3-MPA) is an important thiol intermediate in organic sulfur metabolism in natural environments. It is generated during degradation of sulfur-containing amino acids (e.g. methionine) and from demethylation of dimethylsulfoniopropionate (DMSP). This pathway is an alternative enzymatic process in the DMSP catabolism that routes sulfur away from the climatically-active dimethyl sulfide (DMS). 3-MPA detection and subsequent quantification in different matrices is difficult due to its extreme reactivity. We therefore developed a sensitive method for determination of 3-MPA based on pre-column derivatization with monobromobimane and analysis by high-performance liquid chromatography (HPLC) with fluorescence detection. This methodology was first tested with 3-MPA standards under low (0.005-0.2μmolL(-1)) and high (1-25μmolL(-1)) concentrations. For the optimization of the reaction, CHES and, alternatively, Tris-HCl buffers were evaluated in the derivatization step, with Tris-HCl showing more effective separation of thiol derivatives and a better 3-MPA peak shape. The detection limit was 4.3nmolL(-1) with a 10μL sample injection, and mean recoveries of 3-MPA ranged from 97 to 105% in estuarine waters with different salinities (0.17 and 35.9ppt). The linearity (r>0.99) and repeatability of detector response, with intra- and inter-day precision (% CV) of 2.68-7.01% and 4.86-12.5%, respectively, confirmed the reliability of the method. Previous 3-MPA analytical methods required immediate analysis due to unstable derivatives, but in this method we achieved high stability of the derivatized samples when stored at 4°C, with only a 3-5% loss after more than one year of storage. This method was successfully applied to measure 3-MPA concentrations and rates of 3-MPA production in a variety of intertidal estuarine sediment slurries. Dissolved 3-MPA concentrations in these sediment slurries varied between 2 and 237μmolL(-1) and, 3-MPA net fluxes ranged in wet sediments between -3.6±1.7 and 30±5μmolL(-1)g(-1)h(-1). Thus, the application of this optimized methodology showed an efficient performance for measuring 3-MPA in environmental samples, with a straightforward sample derivatization and a simple analysis of stable 3-MPA derivatives.

show abstract

Automated tagging of pharmaceutically active thiols under flow conditions using monobromobimane

Cited by 8 publications

References 12 publications

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

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

Automated Stopped-Flow Fluorimetric Sensor for Biologically Active Adamantane Derivatives Based on Zone Fluidics

Determination of 3-mercaptopropionic acid by HPLC: A sensitive method for environmental applications

Contact Info

Product

Resources

About