Illumination of Hydroxyl Radical Generated in Cells during Ferroptosis, , and Mice Using a New Turn-On Near-Infrared Fluorescence Probe.

Hydroxyl radical (·OH), taken as the most active and aggressive reactive oxygen species (ROS), plays an important role in cell redox regulation and ferroptosis processes. It is a great challenge to develop methods for highly selective and sensitive detection and imaging of ·OH. A new near-infrared (NIR) fluorescence probe was designed and synthesized by introducing 3-methylpyrazolone as the specific recognition moiety to the hemicyanine backbone of the NIR fluorophore , which formed with the hydrazine group.

Can fiscal decentralization and farmers' use of internent be the route to the digitalization performance in China? A novel approach towards unlocking the role of online marketing behavior and performance of agricultural products.

It is believed that the respondents' disadvantageous positions and the information asymmetry that exists between them are the bottlenecks that contribute to the stagnation of trades and the poor revenue that respondents receive from agro-products. Digitalization and fiscal decentralization both play an important part in helping to increase the information literacy of respondents who live in rural areas. The purpose of this study is to investigate the theoretical effects that the digital revolution has had on environmental behavior and performance, and it also analyzes the part that digitalization plays in the process of fiscal decentralization.

l-Methionine Selenoxide as an Oxidizing and Deprotection Reagent for the Synthesis of Multiple Disulfide Bonds in Peptides.

The regioselective synthesis of multiple disulfide bonds in peptides has been a significant challenge in synthetic peptide chemistry. In this work, two disulfide bonds in peptides were regioselectively synthesized via an approach of MetSeO oxidation and deprotection reaction (SeODR), in which the first disulfide bond was constructed through oxidation of dithiol by MetSeO in a neutral buffer, and the second disulfide bond was then directly constructed through the deprotection of two Acm groups or one Acm group and one Thz group by MetSeO in acidic media. Synthesis of two disulfide bonds by the SeODR approach was achieved through a one-pot manner.

Deprotection of S-Acetamidomethyl and 1,3-Thiazolidine-4-Carbonyl Protecting Groups from Cysteine Side Chains in Peptides by -[PtX(CN)]: One-Pot Regioselective Synthesis of Disulfide Bonds.

In this study, we developed an efficient approach for disulfide bond formation in peptides utilizing the Pt(IV) complex -[PtBr(CN)] to mediate Acm and Thz deprotections. [PtBr(CN)] can oxidatively deprotect two Acm groups or deprotect one Thz group and one Acm group to directly form an intramolecular disulfide bond in peptides. Several disulfide-containing peptides with excellent yields were achieved via the deprotection method in an aqueous medium under aerobic conditions.

Expanding the Toolbox for Peptide Disulfide Bond Formation l-Methionine Selenoxide Oxidation.

In this study, l-methionine selenoxide (MetSeO) was used as an oxidant for the construction of peptide disulfide bonds. Excellent yields for various disulfide-containing peptides were achieved the MetSeO oxidation method in different solvents and on a resin. Most importantly, the construction of disulfide bonds can be performed in the trifluoroacetic acid cocktail used for the cleavage of peptides from the resin, which obviates the steps of peptide purification and lyophilization.

A study to develop platinum(iv) complex chemistry for peptide disulfide bond formation.

Platinum(iv) complexes with a heterocyclic ligand and an ancillary ligand have been investigated and applied for treating various tumour cell lines. Another application of the Pt(iv) complexes in forming peptide disulfide bonds was investigated in this work. For development of Pt(iv) complex chemistry for disulfide bond formation in peptides, two Pt(iv) complexes, [PtCl(phen)(en)]Cl and [PtCl(bpy)(en)]Cl, were synthesized and characterized using elemental analysis, ESI-MS and NMR.

Reduction of ormaplatin by an extended series of thiols unravels a remarkable correlation.

Ormaplatin ([Pt(dach)Cl4]) represents one of the three primary structural prototypes of Pt(iv) anticancer-active prodrugs. The reduction of ormaplatin by an extended series of thiols has been studied kinetically in a broad pH range. A novel and remarkable correlation between log kRS- and the thiol dissociation constants pKRSH is disclosed: log kRS- = (0.

L-selenomethionine reduces platinum(IV) anticancer model compounds at strikingly faster rates than L-methionine.

L-Selenomethionine (SeMet), the predominant form of selenium acquired from the diet by humans, has been used as a supplement, and exhibit some important functions like cancer prevention and antioxidative defense. Its interactions with Pt(II) anticancer drugs have been characterized, but its redox reactions with platinum(IV) anticancer prodrugs have not been exploited. In this work, the oxidation of SeMet by Pt(IV) anticancer model compounds trans-[PtX2(CN)4](2-) (X = Cl, Br) was characterized.

Kinetics and mechanism of reactions of the drug tiopronin with platinum(IV) complexes.

Tiopronin, a synthetic thiol-containing drug being used in treatments of cystinuria and certain types of rare arthritis, is also a hepatoprotective and a detoxifying agent. Many analytical methods have been developed based on its redox chemistry with metal ions/complexes, but the kinetic and mechanistic aspects are poorly understood. In this work, the oxidation of tiopronin by cisplatin prodrug and a model compound, cis-[Pt(NH3)2Cl4] and trans-[PtCl2(CN)4](2-), was investigated.