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Understanding hydrogen sulfide storage: probing conditions for sulfide release from hydrodisulfides.

Bailey TS, Zakharov LN, Pluth MD - J. Am. Chem. Soc. (2014)

Bottom Line: Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides.We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases.Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, Institute of Molecular Biology, Material Science Institute, 1253 University of Oregon , Eugene, Oregon 97403, United States.

ABSTRACT
Hydrogen sulfide (H2S) is an important biological signaling agent that exerts action on numerous (patho)physiological processes. Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides. Despite the importance of hydrodisulfides in H2S storage and signaling, little is known about the physical properties or chemical reactivity of these compounds. We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases. Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

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Reactivity of TrtSSHwith acids, electrophiles (E+),reductants ([red]), bases, or nucleophiles (nuc).
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fig3: Reactivity of TrtSSHwith acids, electrophiles (E+),reductants ([red]), bases, or nucleophiles (nuc).

Mentions: In summary, we have prepared, isolated, and fully characterizedthe stable hydrodisulfide TrtSSH and studied its reactivity towardreductants, nucleophiles, acids, and bases. The chemical reactivitydata obtained from TrtSSH demonstrate that hydrodisulfides do notreact with nucleophiles or acids in organic solution, but rather releasesulfide upon reduction and disproportionate to release S0, likely as S8 under physiological conditions, upon deprotonation(Figure 3). These results clarify the innatereactivity of hydrodisulfides and confirm that hydrodisulfides areviable sources of reductant-labile sulfur. Additionally, deprotonationof hydrodisulfides may provide a mechanism for interconversion ofdifferent species within the reductant-labile sulfur pool, therebyallowing for facile conversion back to the parent thiol without disruptionof thiol or redox homeostasis. We envision that these studies as wellas future work using isolated hydrodisulfides will be invaluable infurthering our understanding of biological H2S signalingand storage by providing clear insight into the reactivity of hydrodisulfidesunder different reactive conditions.


Understanding hydrogen sulfide storage: probing conditions for sulfide release from hydrodisulfides.

Bailey TS, Zakharov LN, Pluth MD - J. Am. Chem. Soc. (2014)

Reactivity of TrtSSHwith acids, electrophiles (E+),reductants ([red]), bases, or nucleophiles (nuc).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120993&req=5

fig3: Reactivity of TrtSSHwith acids, electrophiles (E+),reductants ([red]), bases, or nucleophiles (nuc).
Mentions: In summary, we have prepared, isolated, and fully characterizedthe stable hydrodisulfide TrtSSH and studied its reactivity towardreductants, nucleophiles, acids, and bases. The chemical reactivitydata obtained from TrtSSH demonstrate that hydrodisulfides do notreact with nucleophiles or acids in organic solution, but rather releasesulfide upon reduction and disproportionate to release S0, likely as S8 under physiological conditions, upon deprotonation(Figure 3). These results clarify the innatereactivity of hydrodisulfides and confirm that hydrodisulfides areviable sources of reductant-labile sulfur. Additionally, deprotonationof hydrodisulfides may provide a mechanism for interconversion ofdifferent species within the reductant-labile sulfur pool, therebyallowing for facile conversion back to the parent thiol without disruptionof thiol or redox homeostasis. We envision that these studies as wellas future work using isolated hydrodisulfides will be invaluable infurthering our understanding of biological H2S signalingand storage by providing clear insight into the reactivity of hydrodisulfidesunder different reactive conditions.

Bottom Line: Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides.We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases.Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, Institute of Molecular Biology, Material Science Institute, 1253 University of Oregon , Eugene, Oregon 97403, United States.

ABSTRACT
Hydrogen sulfide (H2S) is an important biological signaling agent that exerts action on numerous (patho)physiological processes. Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides. Despite the importance of hydrodisulfides in H2S storage and signaling, little is known about the physical properties or chemical reactivity of these compounds. We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases. Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

Show MeSH