Intramolecular tetrazine-acryloyl cycloaddition: chemistry and applications.

An unprecedented intramolecular [4 + 2] tetrazine-olefin cycloaddition with α,β-unsaturated substrates was discovered. The reaction produces unique coumarin-dihydropyridazine heterocycles that exhibited strong fluorescence with large Stokes shifts and excellent photo- and pH-stability. This property can be used for reaction analysis.

Is Hydrogen Sulfide a Concern During Treatment of Lung Adenocarcinoma With Ammonium Tetrathiomolybdate?

Ammonium tetrathiomolybdate (ATTM) has been used in breast cancer therapy for copper chelation, as elevated copper promotes tumor growth. ATTM is also an identified HS donor and endogenous HS facilitates VitB-induced S-adenosylmethionine (SAM) generation, which have been confirmed in mA methylation and lung cancer development. The mA modification was recently shown to participate in lung adenocarcinoma (LUAD) progression.

Chemistry and Chemical Biology of Selenenyl Sulfides and Thioseleninic Acids.

Selenenyl sulfides (RSeSRs) and thioseleninic acids (RSeSHs) are the monoselenium (Se) analogs of disulfides and persulfides that contain Se-S bonds. These bonds are found in several antioxidant-regenerating enzymes as derivatives of selenocysteine, making them an important player in redox biology as it pertains to sulfur redox regulation. Mechanistic studies of redox-regulating selenoenzymes such as thioredoxin reductase and glutathione peroxidase suggest crucial Se-S bonds in the active sites.

S-Persulfidation: Chemistry, Chemical Biology, and Significance in Health and Disease.

S-Persulfidation generates persulfide adducts (RSSH) on both small molecules and proteins. This process is believed to be critical in the regulation of biological functions of reactive sulfur species such as HS, as well as in signal transduction. S-Persulfidation also plays regulatory roles in human health and diseases.

Acyl Selenyl Sulfides as the Precursors for Reactive Sulfur Species (Hydrogen Sulfide, Polysulfide, and Selenyl Sulfide).

Persulfides are receiving increased attention due to their links to hydrogen sulfide (HS) and hydrogen polysulfide (HS). Their close analogues selenyl sulfides (RSeSHs), however, have limited literature precedent, and their reactivity and possible role in biology are largely unknown. Here, we devised an acyl selenyl sulfide template to study RSeSH chemistry.

Strategies for the Design of Donors and Precursors of Reactive Sulfur Species.

Reactive sulfur species (RSS) play regulatory roles in biological systems. Many RSS are highly reactive and transient molecules, making their study difficult. RSS donors or precursors, which are used to specifically produce or deliver RSS, are useful research tools, as well as possible therapeutic agents.