Determination of Total Reduced Thiol Levels in Plasma Using a Bromide Substituted Quinone

Lobo, Grace-Ann M.; Chitre, Sneha A.; Rathod, Spandan M.; Leslie, R. Vincent; Livingstone, Callum; Davis, James A.

doi:10.1002/elan.200703977

Cited by 4 publications

(5 citation statements)

References 20 publications

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“…In our tests, NQBr did not react with hydroxyl or carboxyl groups (tested with salicylic acid, data not shown). These findings are consistent with Lobo et al (2007) who also found that NQBr is a selective reagent for thiols in complex matrices. Interestingly, the reagent gave not only the mono-reacted product but also the di-reacted one (Fig.…”

Section: Thiol Derivatizationsupporting

confidence: 94%

“…To detect thiol groups in the DOM samples, we added 2-bromo-1,4-naphthoquinone (NQBr, 98%, Sigma-Aldrich, Germany) which selectively adds to thiol groups (Lobo et al, 2007) (Fig. 1).…”

Section: Thiol Derivatizationmentioning

confidence: 99%

“…For the more stable sulfur-containing functional groups we hypothesized that they are possibly occurring in the ocean. The presence of thiols was analyzed by usage of the derivatization reagent 2-bromo-1,4-naphthoquinone that selectively adds to thiol groups (Lobo et al, 2007). To test for non-aromatic thioethers an oxidation reaction was applied and for sulfoxides a deoxygenation reaction (Bahrami et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

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Novel insights into the molecular structure of non-volatile marine dissolved organic sulfur

Pohlabeln

Dittmar

2015

Marine Chemistry

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Section: Thiol Derivatizationsupporting

confidence: 94%

“…To detect thiol groups in the DOM samples, we added 2-bromo-1,4-naphthoquinone (NQBr, 98%, Sigma-Aldrich, Germany) which selectively adds to thiol groups (Lobo et al, 2007) (Fig. 1).…”

Section: Thiol Derivatizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Novel insights into the molecular structure of non-volatile marine dissolved organic sulfur

Pohlabeln

Dittmar

2015

Marine Chemistry

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“…This first order rate constant compares to that of 100 μM cell-free Hb with nitroxyl (about 10 3 s −1 ), so that reaction of HNO with plasma components could explain our lower than expected yield of metHb during AS infusion. The first order rate constant for the reaction of plasma and HNO obtained by the above method is also consistent with published values of plasma thiol levels (about 0.5 mM) [53] and rate constants (about 2 × 10 6 M −1 s −1 ), [49] predicting an observed rate constant of 10 3 s −1 . These observed rate constants would predict that thiols can compete with plasma Hb for HNO and that the lifetime of HNO in plasma would be on the order of milliseconds.…”

Section: Discussionsupporting

confidence: 90%

Angeli's salt counteracts the vasoactive effects of elevated plasma hemoglobin

Solomon

Bellavia²,

Sweeney

et al. 2012

Free Radical Biology and Medicine

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Plasma hemoglobin (Hb) released during intravascular hemolysis has been associated with numerous deleterious effects that may stem from increased nitric oxide (NO) scavenging, but has also been associated with reactive oxygen species generation and platelet activation. Therapies that convert plasma oxyHb to metHb, or metHb to iron-nitrosyl Hb, could be beneficial because these species do not scavenge NO. In this study, we investigated the effects of Angeli’s Salt (AS, sodium α-oxyhyponitrite, Na2N2O3), a nitroxyl (HNO) and nitrite (NO2−) donor, on plasma Hb oxidation and formation of iron-nitrosyl Hb from metHb, and on the vasoactivity of plasma Hb. We hypothesized that AS could ameliorate hemolysis-associated pathology via its preferential reactivity with plasma Hb, as opposed to red cell encapsulated Hb, and through its intrinsic vasodilatory activity. To test this hypothesis, we infused (n=3 per group) (1) cell-free Hb and AS, (2) cell-free Hb + 0.9% NaCl, (3) AS + 3% Albumin, and (4) 3% Albumin + 0.9% NaCl (colloid controls for Hb and AS, respectively) in a canine model. Co-infusion of AS and cell-free Hb led to preferential conversion of plasma Hb to metHb, but the extent of conversion was lower than anticipated based on the in vivo concentration of AS relative to plasma Hb. This lower metHb yield was likely due to reactions of nitroxyl-derived AS with plasma components such as thiol-containing compounds. From a physiological and therapeutic standpoint, the infusion of Hb alone led to significant increases in mean arterial pressure (p=0.03) and systemic vascular resistance index (p=0.01) compared to controls. Infusion of AS alone led to significant decreases in these parameters and co-infusion of AS along with Hb had an additive effect on reversing the effects of Hb alone on the systemic circulation. Interestingly, in the pulmonary system, the decrease in pressure when AS is added to Hb was significantly less than would have been expected compared to the effects of Hb and AS alone suggesting that inactivation of scavenging with AS reduced the direct vasodilatory effects of AS on the vasculature. We also found that, AS reduced platelet activation when administered to whole blood in vitro. These data suggest that AS-like compounds could serve as a therapeutic agent to counteract the negative vasoconstrictive consequences of hemolysis that occur in hemolytic anemia’s, transfusion of stored blood, and other diseases. Increases in metHb in the red blood cell, the potential of AS for neurotoxicity, and hypotension would need to be carefully monitored in a clinical trial.

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“…In contrast to the many studies on biological samples (blood or intracellular content) (e.g., Lobo et al 2007), there is limited data on LMM thiol analysis for natural water samples. Therefore, the overall aim of this study is to establish the optimal storage conditions and proper handling of natural water samples.…”

mentioning

confidence: 99%

Freshwater sample preservation for the analysis of dissolved low molecular mass thiols

Leclerc

Planas

Amyot

2017

Limnology & Ocean Methods

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Low molecular mass (LMM) thiols are ubiquitous organosulfur peptides that play key roles in biogeochemical element cycling. These LMM thiols, found at low concentrations in the water column, are highly sensitive to oxidation and degradation processes which may lead to problems with detection and analysis. Natural water samples should be stored and handled appropriately to reduce thiol loss in the time period from sampling to analysis. Storage temperatures were investigated for optimal preservation of four thiols species. Thiol degradation varied between species and was generally slower in samples stored at −80°C and 4°C compared to −20°C and 21°C. Two natural freshwater matrices were tested, one from a fluvial lake subject to agricultural inputs and one from an oligotrophic pristine lake. After 6 d of storage at −20°C, the most affected thiol species was glutathione with a degradation rate (kD) of (3.0 ± 0.5) × 10−3 h−1 in the fluvial lake water and l‐cysteine‐l‐glycine (CYS‐GLY) with a kD of (3.8 ± 0.8) × 10−3 h−1 in the oligotrophic lake water. Argon purging of samples did not prevent thiol degradation or oxidation after storage for 7 d. Pre‐concentration by freeze‐drying techniques led to significant loss for every thiol species tested (up to 65% for cysteine). We recommend improving storage methods by using temperatures of −80°C or 4°C. The use of correction factors to estimate initial thiol concentrations is possible but should be used with caution due to highly site‐specific kD in natural waters.

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Determination of Total Reduced Thiol Levels in Plasma Using a Bromide Substituted Quinone

Cited by 4 publications

References 20 publications

Novel insights into the molecular structure of non-volatile marine dissolved organic sulfur

Novel insights into the molecular structure of non-volatile marine dissolved organic sulfur

Angeli's salt counteracts the vasoactive effects of elevated plasma hemoglobin

Freshwater sample preservation for the analysis of dissolved low molecular mass thiols

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