2,2'-Bipyridine-Enabled Photocatalytic Radical [4+2] Cyclization of N-Aryl-α-amino Acids for Synthesizing Polysubstituted Tetrahydroquinolines.

A facile photocatalytic radical [4+2] cyclization of N-aryl-α-amino acids with various alkenes to access structurally polysubstituted tetrahydroquinolines has been developed. Using a simple bipyridine as a catalyst, different N-aryl-α-amino acids could be utilized as the radical precursors to react with diverse electrophilic alkenes, including exocyclic terminal alkenes, acyclic terminal alkenes, and cycloalkenes, producing 10 types of nitrogen-containing heterocyclic compounds fused in multiple frameworks in generally moderate yields with good diastereoselectivities. Scale-up synthesis and transformations of the products further demonstrated the synthetic application of this protocol. Moreover, a decarboxylative radial pathway via a proton-coupled electron transfer process for illustration of this [4+2] cyclization was proposed on the basis of the control experiments. This process is highlighted by a simple bipyridine photocatalysis, mild reaction conditions, various N-aryl-α-amino acids and alkene materials, and application for the modification of natural products.

Iron(II)-Catalyzed Radical [3 + 2] Cyclization of N-Aryl Cyclopropylamines for the Synthesis of Polyfunctionalized Cyclopentylamines.

A facile iron(II)-catalyzed radical [3 + 2] cyclization of N-aryl cyclopropylamines with various alkenes to access the structurally polyfunctionalized cyclopentylamine scaffolds has been developed. Using low-cost FeCl2·4H2O as catalyst, N-aryl cyclopropylamines could be utilized to react with a wide range of alkenes including exocyclic/acyclic terminal alkenes, cycloalkenes, alkenes from the natural-occurring compounds (Alantolactone, Costunolide), and known drugs (Ibuprofen, l-phenylalanine, Flurbiprofen) to obtain a variety of cyclopentylamines fused with different useful motifs in generally good yields and diastereoselectivities. The highlight of this protocol is also featured by no extra oxidant, no base, EtOH as the solvent, gram-scale synthesis, and further diverse transformations of the synthetic products. More importantly, an iron(II)-mediated hydrogen radical dissociation pathway was proposed based on the mechanism research experiments.

Enantiocomplementary synthesis of ß-adrenergic blocker precursors via biocatalytic nitration of phenyl glycidyl ethers.

Enantiopure ß-nitroalcohols, as an important class of nitro-containing compounds, are essential building blocks in pharmaceutical and organic chemistry, particularly for the synthesis of ß-adrenergic blockers. In this study, we present the successful protein engineering of halohydrin dehalogenase HHDHamb for the enantioselective bio-nitration of various phenyl glycidyl ethers to the corresponding chiral ß-nitroalcohols, using the inexpensive, commercially available, and safer nitrite as a nitrating agent. The chiral (R)- and (S)-1-nitro-3-phenoxypropan-2-ols were synthesized by the several enantiocomplementary HHDHamb variants through the whole-cell biotransformation, which showed good catalytic efficiency (up to 43% isolated yields) and high optical purity (up to >99% ee). In addition, we also demonstrated that the bio-nitration method was able to tolerate the substrate at a high concentration of 1000 mM (150 g/L). Furthermore, representative synthesis of two optically active enantiomers of the ß-adrenergic blocker metoprolol was successfully achieved by utilizing the corresponding chiral ß-nitroalcohols as precursors.

Ethyl Vanillin Rapid Crystallization from Carboxymethyl Chitosan Ion-Switchable Hydrogels.

Polymer gels are usually used for crystal growth as the recovered crystals have better properties. Fast crystallization under nanoscale confinement holds great benefits, especially in polymer microgels as its tunable microstructures. This study demonstrated that ethyl vanillin can be quickly crystallized from carboxymethyl chitosan/ethyl vanillin co-mixture gels via classical swift cooling method and supersaturation. It found that EVA appeared with bulk filament crystals accelerated by a large quantity of nanoconfinement microregions resulted from space-formatted hydrogen network between EVA and CMCS when their concentration exceeds 1:1.4 and may occasionally arise when the concentration less than 1:0.8. It was observed that EVA crystal growth has two models involving hang-wall growth at the air-liquid interface at the contact line, as well as extrude-bubble growth at any sites on the liquid surface. Further investigations found that EVA crystals can be recovered from as-prepared ion-switchable CMCS gels by 0.1 M hydrochloric acid or acetic acid without defects. Consequently, the proposed method may offer an available scheme for a large-scale preparation of API analogs.

Electrochemically Enabled Intramolecular Amino- and Oxysulfonylation of Alkenes with Sodium Sulfinates to Access Sulfonylated Saturated Heterocycles.

A practical and efficient electrochemical intramolecular amino- or oxysulfonylation of internal alkenes equipped with pendant nitrogen or oxygen-centered nucleophiles with sodium sulfinate was developed. Under undivided electrolytic cell conditions, a variety of sulfonylated N-heterocycles and O-heterocycles, such as tetrahydrofurans, tetrahydropyrans, oxepanes, tetrahydropyrroles, piperidines, δ-valerolactones, etc., were efficiently prepared from easily accessible unsaturated alcohols, carboxylic acids, and N-tosyl amines without the need for additional metal or exogenous oxidant. The robust electrochemical transformation features excellent redox economy, high diastereoselectivity, and broad substrate specificity, which provide a general and practical access to sulfone-containing heterocycles and would facilitate the related synthetic and biological studies based on this electrosynthesis.

Exploring a novel seven-gene marker and mitochondrial gene TMEM38A for predicting cervical cancer radiotherapy sensitivity using machine learning algorithms.

Background: Radiotherapy plays a crucial role in the management of Cervical cancer (CC), as the development of resistance by cancer cells to radiotherapeutic interventions is a significant factor contributing to treatment failure in patients. However, the specific mechanisms that contribute to this resistance remain unclear. Currently, molecular targeted therapy, including mitochondrial genes, has emerged as a new approach in treating different types of cancers, gaining significant attention as an area of research in addressing the challenge of radiotherapy resistance in cancer. Methods: The present study employed a rigorous screening methodology within the TCGA database to identify a cohort of patients diagnosed with CC who had received radiotherapy treatment. The control group consisted of individuals who demonstrated disease stability or progression after undergoing radiotherapy. In contrast, the treatment group consisted of patients who experienced complete or partial remission following radiotherapy. Following this, we identified and examined the differentially expressed genes (DEGs) in the two cohorts. Subsequently, we conducted additional analyses to refine the set of excluded DEGs by employing the least absolute shrinkage and selection operator regression and random forest techniques. Additionally, a comprehensive analysis was conducted in order to evaluate the potential correlation between the expression of core genes and the extent of immune cell infiltration in patients diagnosed with CC. The mitochondrial-associated genes were obtained from the MITOCARTA 3.0. Finally, the verification of increased expression of the mitochondrial gene TMEM38A in individuals with CC exhibiting sensitivity to radiotherapy was conducted using reverse transcription quantitative polymerase chain reaction and immunohistochemistry assays. Results: This process ultimately led to the identification of 7 crucial genes, viz., GJA3, TMEM38A, ID4, CDHR1, SLC10A4, KCNG1, and HMGCS2, which were strongly associated with radiotherapy sensitivity. The enrichment analysis has unveiled a significant association between these 7 crucial genes and prominent signaling pathways, such as the p53 signaling pathway, KRAS signaling pathway, and PI3K/AKT/MTOR pathway. By utilizing these 7 core genes, an unsupervised clustering analysis was conducted on patients with CC, resulting in the categorization of patients into three distinct molecular subtypes. In addition, a predictive model for the sensitivity of CC radiotherapy was developed using a neural network approach, utilizing the expression levels of these 7 core genes. Moreover, the CellMiner database was utilized to predict drugs that are closely linked to these 7 core genes, which could potentially act as crucial agents in overcoming radiotherapy resistance in CC. Conclusion: To summarize, the genes GJA3, TMEM38A, ID4, CDHR1, SLC10A4, KCNG1, and HMGCS2 were found to be closely correlated with the sensitivity of CC to radiotherapy. Notably, TMEM38A, a mitochondrial gene, exhibited the highest degree of correlation, indicating its potential as a crucial biomarker for the modulation of radiotherapy sensitivity in CC.

Complementary Copper-Catalyzed and Electrochemical Aminosulfonylation of O-Homoallyl Benzimidates and N-Alkenyl Amidines with Sodium Sulfinates.

A complementary copper-catalyzed and electrochemical aminosulfonylation of O-homoallyl benzimidates and N-alkenyl amidines with sodium sulfinates was developed. The terminal alkene substrate produced sulfone-containing 1,3-oxazines and tetrahydropyrimidines in the presence of Cu(OAc)2, Ag2CO3, and DPP, and under similar reaction conditions, sulfonylated tetrahydro-1,3-oxazepines were prepared from 1-aryl-substituted O-homoallyl benzimidates in moderate to good yields. For certain electron-rich 1,1-diaryl-substituted alkene substrates, the corresponding tetrahydro-1,3-oxazepines could also be obtained in similar or even higher yields via a green electrochemical technique.

Copper(I)-Catalyzed Enantioselective Intramolecular Aminotrifluoromethylation of O-Homoallyl Benzimidates.

In the present paper, the Cu(I)-catalyzed intramolecular aminotrifluoromethylation of O-homoallyl benzimidates with Togni reagent I was reported. O-Homoallyl benzimidates equipped with terminal alkenes produced chiral 1,3-oxazines with high enantioselectivity in the presence of a chiral BOX ligand, and racemic tetrahydro-1,3-oxazepines were obtained in high yields from internal alkene derivatives with a monoprotected amino acid additive under similar conditions.

GZMB gene silencing confers protection against synovial tissue hyperplasia and articular cartilage tissue injury in rheumatoid arthritis through the MAPK signaling pathway.

INTRODUCTION: Rheumatoid arthritis (RA) represents the most commonly occurring inflammatory type of arthritis and is a major cause of disability. Reports have placed emphasis on the potential of, granzyme B (GZMB) as a potentially valuable prognostic marker in early RA, the mechanism of which still remains largely unclear. Thus, the aim of the current study was to investigate the effects GZMB gene silencing influences synovial tissue hyperplasia and articular cartilage tissue injury of RA through the regulation of the MAPK signaling pathway. METHODS: Following the successful establishment of the collagen-induced animal model of RA in rats, a five-grade scoring method was applied to evaluate the swelling degree measurement of the rats for model identification. The various rat responses to GZMB shRNA and U-46619 (activator of the MAPK signaling pathway) were subsequently detected. The general status of rats was observed and recorded, with their weight and ankle diameter kept accurate record of. ELISA was employed to detect the levels of inflammatory cytokines, while RT-qPCR and Western blotting techniques were applied to determine the expressions of GZMB and pathway-related genes and proteins. RESULTS: GZMB gene silencing was observed to aid in the maintenance of rat weight increases, while acting to reduce the degree of ankle swelling, while hypertrophy of the synovial tissue and the injury of the articular cartilage tissue were not obvious. GZMB gene silencing was shown to decrease inflammatory cytokine levels, as well as decreased bcl-2, Cyclin D1, VEGF and bFGF while increasing caspase 3. Notably, GZMB gene silencing suppressed the activation of the MAPK signaling pathway by reducing the phosphorylation extent of ERK and MEK. CONCLUSION: Taken together, the key findings of the present study ultimately suggest that GZMB gene silencing acts to inhibit MAPK signaling pathway through regulating the expressions of inflammatory factors, factors correlated with apoptosis (bcl-2 and caspase), as well as factors associated with angiogenesis (VEGF and bFGF), thus relieving synovial tissue hyperplasia and articular cartilage tissue injury brought about by RA. The GZMB gene could well be a new therapeutic target for RA treatment.

Radical C-H Arylation of Oxazoles with Aryl Iodides: dppf as an Electron-Transfer Mediator for Cs2CO3.

A radical C-H arylation reaction of oxazoles with (hetero)aryl iodides using Cs2CO3 as base/electron donor and 1,1'-bis(diphenylphosphino) ferrocene (dppf) as a catalytic SET mediator is reported. The overall reaction likely follows the general base-promoted homolytic aromatic substitution mechanism through a radical-chain pathway. DFT calculations suggest that dppf forms a complex with CsCO3-, enhancing its SET reducing ability to generate an aryl radical from ArI.

Radical-mediated intramolecular ß-C(sp3)-H amidation of alkylimidates: facile synthesis of 1,2-amino alcohols.

A new radical-mediated intramolecular ß-C(sp3)-H amidation reaction of O-alkyl trichloro- or arylimidates is reported. Various oxazolines were efficiently prepared from easily accessible alcohol starting materials. The trichloro-oxazoline products can be hydrolyzed under mild conditions to give valuable 1,2-amino alcohols. This amidation reaction exhibits a broad substrate scope and good functional group tolerance, and offers a powerful means for the C(sp3)-H functionalization of alcohols. Mechanistic studies suggest that a sequence of 1,5-HAT of an imidate radical, iodination and cyclization might be operative.

The synthesis of cycloalka[b]furans via an Au(i)-catalyzed tandem reaction of 3-yne-1,2-diols.

An Au(i)-catalyzed cyclization/1,2-rearrangement/aromatization cascade of 3-yne-1,2-diols has been successfully realized. This reaction not only provides a new and efficient strategy for the synthesis of substituted cycloalka[b]furan compounds as well as their derivatives, but might also facilitate related biological studies.

Zinc-promoted cyclization of tosylhydrazones and 2-(dimethylamino)malononitrile: an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles.

A Zn(OTf)2-promoted cyclization reaction of tosylhydrazones with 2-(dimethylamino)malononitrile has been successfully developed providing an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles.

Anti-inflammatory activity effect of 2-substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole on TPA-induced skin inflammation in mice.

2-Substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole, a key structural moiety exiting in many bioactive molecules, has been shown to have excellent selective activity on COX-2. In the present study, the anti-inflammatory activity and the underlying molecular mechanism of 2-substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole on skin inflammation were assessed by 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mice. Most of the compounds showed anti-inflammatory activity on TPA-induced skin inflammation. The anti-inflammatory activity of compound 4 showed higher anti-inflammatory activity than celecoxib (3.2-fold). Compound 4 pretreatment resulted in markedly suppression of TPA-induced IL-1ß, IL-6, TNF-α, and COX-2, respectively. Furthermore, the mechanical study indicated that the anti-inflammatory activity of compound 4 was associated with its ability to inhibit activation of factor kappa-κB (NF-κB) by blocking IκB kinase (IKK) activities. Accordingly, compound 4 could be used as a potential anti-inflammatory agent for skin inflammation.

The Synthesis of Multisubstituted Pyrroles via a Copper-Catalyzed Tandem Three-Component Reaction.

An unprecedented nucleophilic addition/cyclization/aromatization cascade of basic chemicals, i.e., aromatic alkenes/alkynes, trimethylsilyl cyanide and N,N-disubstituted formamide, has been developed to give a series of multisubstituted pyrroles in moderate to good yields with high regioselectivities. This reaction not only reveals a new reaction mode for α-aminonitriles, but also provides a new and efficient cyclization pattern for the synthesis of multisubstituted pyrroles as well as their derivatives, which might facilitate related biological studies.

A Tin(IV) Chloride Promoted Tandem C-O Bond Cleavage/Nazarov Cyclization/Nucleophilic Addition Reaction of 1,1-Disubstituted Allylic Ethers toward the Synthesis of Multisubstituted Indenes.

A novel SnCl4-promoted tandem reaction toward multisubstituted indenes via a sequential C-O bond cleavage/Nazarov cyclization/nucleophilic addition reaction has been developed to afford a series of multisubstituted indenes with an all-carbon quaternary center in moderate to good yields.

An Au(I)-catalyzed rearrangement/cyclization cascade toward the synthesis of 2-substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole.

An Au(I)-catalyzed tandem reaction for the synthesis of 2-phenyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole derivatives from 1-(1-hydroxy-3-phenylprop-2-yn-1-yl)cyclobutanol and primary amines or NH4OAc has been developed to afford a series of polysubstituted pyrroles in moderate to good yields.

Copper-catalyzed intermolecular azidocyanation of aryl alkenes.

A copper-catalyzed Markovnikov-type intermolecular azidocyanation of aryl alkenes has been developed to give a series of α-azido-propanenitriles in moderate to good yields. This method may provide a potential strategy for the synthesis of corresponding 3-amino-2-arylpropanoic acid.

Identification of three H1N1 influenza virus groups with natural recombinant genes circulating from 1918 to 2009.

In this study, we identify a recombinant pb1 gene, a recombinant MP segment and a recombinant PA segment. The pb1 gene is recombined from two Eurasia swine H1N1 influenza virus lineages. It belongs to a H1N1 swine clade circulating in Europe and Asia from 1999 to 2009. The mosaic MP segment descends from H7 avian and H1N1 human virus lineages and pertains to a large human H1N1 virus family circulating in Asia, Europe and America from 1918 to 2007. The recombinant PA segment originated from two swine H1N1 lineages is found in a swine H1N1 group prevailing in Asia and Europe from 1999 to 2003. These results collectively falsify the hypothesis that influenza virus do not evolve by homologous recombination. Since recombination not only leads to virus genome diversity but also can alter its host adaptation and pathogenecity; the genetic mechanism should not be neglected in influenza virus surveillance.