Visible-light-induced cross-coupling of aryl iodides with hydrazones an EDA-complex.

A visible-light-induced, transition-metal and photosensitizer-free cross-coupling of aryl iodides with hydrazones was developed. In this strategy, hydrazones were used as alternatives to organometallic reagents, in the absence of a transition metal or an external photosensitizer, making this cross-coupling mild and green. The protocol was compatible with a variety of functionalities, including methyl, methoxy, trifluoromethyl, halogen, and heteroaromatic rings.

Synthesis and structure-activity relationships of pirfenidone derivatives as anti-fibrosis agents .

Pirfenidone (PFD) was the first approved drug by FDA for the treatment of idiopathic pulmonary fibrosis (IPF). However, the rapid metabolism of 5-methyl of PFD increases the risk of side effects in clinics. Thus, in this paper, a common practice that a stable amide bond linking various groups used to replace 5-methyl of PFD in medicinal chemistry was applied, and total 18 PFD derivatives were synthesized.

A general electron donor-acceptor complex for photoactivation of arenes thianthrenation.

General photoactivation of electron donor-acceptor (EDA) complexes between arylsulfonium salts and 1,4-diazabicyclo[2.2.2]octane with visible light or natural sunlight was discovered.

A reversible plasmonic nanoprobe for dynamic imaging of intracellular pH during endocytosis.

Understanding the pH evolution during endocytosis is essential for our comprehension of the fundamental processes of biology as well as effective nanotherapeutic design. Herein, we constructed a plasmonic Au@PANI core-shell nanoprobe, which possessed significantly different scattering properties under acidic and basic conditions. Encouragingly, the scattering signal of Au@PANI nanoprobes displayed a positive linear correlation with the pH value not only in PBS but also in nigericin-treated cells.

Al-doped α-MnO coated by lignin for high-performance rechargeable aqueous zinc-ion batteries.

Zn/MnO batteries, one of the most widely studied rechargeable aqueous zinc-ion batteries, suffer from poor cyclability because the structure of MnO is labile with cycling. Herein, the structural stability of α-MnO is enhanced by simultaneous Al doping and lignin coating during the formation of α-MnO crystals in a hydrothermal process. Al enters the [MnO] octahedron accompanied by producing oxygen vacancies, and lignin further stabilizes the doped Al strong interaction in the prepared material, Al-doped α-MnO coated by lignin (L + Al@α-MnO).

(LaSr)FeO perovskite with high oxygen vacancy as efficient bifunctional electrocatalysts for Zn-air batteries.

Developing low-cost, highly efficient electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is desirable for rechargeable metal-air batteries. Herein, a series of perovskite structured (LaSr)FeO catalysts with A-site deficiency were synthesized through a scalable solid state synthesis method at different calcination temperatures. The electrocatalytic activities of these catalysts were investigated by thin-film RDE technique.

Hydrazone connected stable luminescent covalent-organic polymer for ultrafast detection of nitro-explosives.

Developing promising luminescent probes for the selective sensing of nitro-explosives remains a challenging issue. Porous luminescent covalent-organic polymers are one of the excellent sensing probes for trace hazardous materials. Herein, fluorescent monomers 1,1,2,2-tetrakis(4-formyl-(1,1'-biphenyl))ethane (TFBE) and 1,3,5-benzenetricarboxylic acid trihydrazide (BTCH) were selected to build a novel hydrazone connected stable luminescent covalent-organic polymer (H-COP) of high stability by typical Schiff-base reaction.

Development of a fluorescent immunochromatographic assay based on quantum dots for the detection of fleroxacin.

Fleroxacin (FLE) is a broad-spectrum fluoroquinolone antibiotic widely used in animal husbandry, veterinary medicine and aquaculture. Eating animal-derived foods with FLE residues can cause allergies, poisoning or drug resistance. The water-soluble QDs (CdSe/ZnS) and anti-FLE monoclonal antibody (mAb) were used to prepare a fluorescent probe by the method of -(3-dimethylaminopropyl)-'-ethylcarbodimide hydrochloride (EDC) activation.

Antifouling hydrogel film based on a sandwich array for salivary glucose monitoring.

A glucose biosensor prepared using interpenetrating polymer network (IPN) hydrogel as a sensing material is the subject of growing interest due to its fast response and high sensitivity. However, the IPN hydrogel circumvents the traditional antifouling strategy, which often requires thick antifouling coating that can result in poor glucose sensitivity owing to its energetic physical barrier (greater than 43 nm); thus a complex, time-consuming and high-cost salivary preprocessing is needed to remove protein contaminants before salivary glucose detection using the IPN hydrogel. This limits its practical application in trace salivary glucose-level monitoring.

Polysaccharide from rubescens: extraction, optimization, characterization and antioxidant activities.

In this work, rubescens polysaccharide was extracted and extraction conditions were optimized with the response surface method (RSM). The extracted polysaccharide was structurally elucidated and its antioxidant activity was investigated. The best extraction conditions were as follows: the solvent-solid ratio was 33.

(Fluoro)alkylation of alkenes promoted by photolysis of alkylzirconocenes.

Difluoroalkylated compounds have important applications in pharmaceutical, agrochemical, and materials science. However, efficient methods to construct the alkylCF-alkyl bond are very limited, and the site-selective introduction of a difluoromethylene (CF) group into an aliphatic chain at the desired position remains challenging. Here, we report an unprecedented example of alkylzirconocene promoted difluoroalkylation of alkyl- and silyl-alkenes with a variety of unactivated difluoroalkyl iodides and bromides under the irradiation of visible light without a catalyst.

Advanced applications of cerium oxide based nanozymes in cancer.

Cerium oxide nanozymes have emerged as a new type of bio-antioxidants in recent years. CeO nanozymes possess enzyme mimetic activities with outstanding free radical scavenging activity, facile synthesis conditions, and excellent biocompatibility. Based on these extraordinary properties, use of CeO nanozymes has been demonstrated to be a highly versatile therapeutic method for many diseases, such as for inflammation, rheumatoid arthritis, hepatic ischemia-reperfusion injury and Alzheimer's disease.

Unveiling the mechanism of high-performance hydrogen evolution reaction on noble-metal-free (113)-faceted NiC: calculations.

To examine the reactivity of noble-metal-free NiC towards hydrogen evolution reaction (HER), we report a comprehensive first-principles density functional theory (DFT) study on the stability, geometric structure, electronic characteristics, and catalytic activity for HER on the NiC crystal (113) surfaces with different surface terminations, namely the C-rich and Ni-rich terminated surface of NiC (113). The results indicate that C-rich and some stoichiometric surfaces are thermodynamically stable. The bridge-site of C-rich NiC (113) is indispensable for HER because it not only displays improved electrocatalytic activity, but also possesses appropriate hydrogen adsorption energy, overpotential and robust stability.

Optimization of dialdehyde soluble soybean polysaccharide: preparation by response surface methodology for cleaner leather tanning.

Leather is widely used in daily necessities, such as shoes and bags. Traditional chrome tanning might produce leathers with excellent mechanical and thermal properties but gives rise to problems, such as environmental pollution. To find an ecological alternative for chrome-tanning agents, soluble soybean polysaccharide (SSPS) was oxidized by sodium periodate to yield dialdehyde soluble soybean polysaccharide (DPA).

A novel AIE-active imidazolium macrocyclic ratiometric fluorescence sensor for pyrophosphate anion.

An imidazolium bridged macrocyclophane was synthesized as a ratiometric fluorescence sensor with aggregation-induced emission (AIE) characteristic to detect pyrophosphate anion with high selectivity among various anions. In the presence of zinc ion, macrocyclophane can form aggregates through complexation with pyrophosphate anion and emit ratiometric fluorescence, resulting from an enhancement in its aggregate-state emission and a reduction in its monomer emission. This AIE-active macrocycle showed great potential as a ratiometric fluorescence receptor.

Recent advances in photochemical and electrochemically induced thiocyanation: a greener approach for SCN-containing compound formation.

Techniques utilizing photo- and electrochemically induced reactions have been developed to accelerate organic processes. These techniques use light or electrical energy (electron transfer) as a direct energy source without using an initiator or reagent. Thiocyanates are found in biologically active and pharmacological compounds and can be converted into various functional groups.

Skeletal remodeling of chalcone-based pyridinium salts to access isoindoline polycycles and their bridged derivatives.

Simultaneous deconstructive ring-opening and skeletal reconstruction of an inert, aromatic pyridinium ring is of great importance in synthetic communities. However, research in this area is still in its infancy. Here, a skeletal re-modeling strategy was developed to transform chalcone-based pyridinium salts into structurally intriguing polycyclic isoindolines through a dearomative ring-opening/ring-closing sequence.

Ritter-type iodo(iii)amidation of unactivated alkynes for the stereoselective synthesis of multisubstituted enamides.

The Ritter reaction, Brønsted- or Lewis acid-mediated amidation of alkene or alcohol with nitrile a carbocation, represents a classical method for the synthesis of tertiary amides. Although analogous reactions through a vinyl cation or a species alike may offer a route to enamide, an important synthetic building block as well as a common functionality in bioactive compounds, such transformations remain largely elusive. Herein, we report a Ritter-type -difunctionalization of alkynes with a trivalent iodine electrophile and nitrile, which affords β-iodanyl enamides in moderate to good yields.

A plasmon-enhanced theranostic nanoplatform for synergistic chemo-phototherapy of hypoxic tumors in the NIR-II window.

Development of simple and effective synergistic therapy by combination of different therapeutic modalities within one single nanostructure is of great importance for cancer treatment. In this study, by integrating the anticancer drug DOX and plasmonic bimetal heterostructures into zeolitic imidazolate framework-8 (ZIF-8), a stimuli-responsive multifunctional nanoplatform, DOX-Pt-tipped Au@ZIF-8, has been successfully fabricated. Pt nanocrystals with catalase-like activity were selectively grown on the ends of the Au nanorods to form Pt-tipped Au NR heterostructures.

[Effect of Nrf2/HO-1 signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis in mice].

The present study aimed to explore the effect of nuclear factor erythroid 2 related factor 2(Nrf2)/heme oxygenase-1(HO-1) signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis(UC). After the UC model was induced by 3% dextran sodium sulfate(DSS), experimental animals were randomly divided into control group, model group, salazosulfapyridine(SASP) group, and low-and high-dose Sishen Pills groups. Drug intervention(ig) was performed for seven consecutive days during modeling.

Nanozyme for tumor therapy: Surface modification matters.

As the next generation of artificial enzymes, nanozymes have shown unique properties compared to its natural counterparts, such as stability in harsh environment, low cost, and ease of production and modification, paving the way for its biomedical applications. Among them, tumor catalytic therapy mediated by the generation of reactive oxygen species (ROS) has made great progress mainly from the peroxidase-like activity of nanozymes. FeO nanozymes, the earliest type of nanomaterial discovered to possess peroxidase-like activity, has consequently received wide attention for tumor therapy due to its ROS generation ability and tumor cell killing ability.

Atroposelective synthesis of -aryl peptoid atropisomers a palladium(ii)-catalyzed asymmetric C-H alkynylation strategy.

The introduction of chirality into peptoids is an important strategy to determine a discrete and robust secondary structure. However, the lack of an efficient strategy for the synthesis of structurally diverse chiral peptoids has hampered the studies. Herein, we report the efficient synthesis of a wide variety of -aryl peptoid atropisomers in good yields with excellent enantioselectivities (up to 99% yield and 99% ee) by palladium-catalyzed asymmetric C-H alkynylation.

Site-selective functionalization of remote aliphatic C-H bonds C-H metallation.

Directing group assistance provided a paradigm for controlling site-selectivity in transition metal-catalyzed C-H functionalization reactions. However, the kinetically and thermodynamically favored formation of 5-membered metallacycles has greatly hampered the selective activation of remote C(sp)-H bonds larger-membered metallacycles. Recent development to achieve remote C(sp)-H functionalization the C-H metallation process largely relies on employing specific substrates without accessible proximal C-H bonds.

Discovery of cryptic allosteric sites using reversed allosteric communication by a combined computational and experimental strategy.

Allostery, which is one of the most direct and efficient methods to fine-tune protein functions, has gained increasing recognition in drug discovery. However, there are several challenges associated with the identification of allosteric sites, which is the fundamental cornerstone of drug design. Previous studies on allosteric site predictions have focused on communication signals propagating from the allosteric sites to the orthosteric sites.

Spatiotemporally controlled O and singlet oxygen self-sufficient nanophotosensitizers enable the high-yield synthesis of drugs and efficient hypoxic tumor therapy.

Carrying out the syntheses of drugs toxic to tumors based on the specific features of the tumor microenvironment is critical for ensuring specific antitumor efficacy. However, achieving high-yield synthetic toxic drugs from non-toxic agents and reducing their drug resistance in hypoxic tumors remain challenges. Herein we created a tumor-microenvironment-responsive porous Pt/Pt(iv) methylene blue coordination polymer nanoshuttle (Pt/PtMBCPNS) photosensitizer with spatiotemporally controlled O and singlet oxygen (O) self-sufficient for the high-yield synthesis of drugs and efficient hypoxic tumor therapy.