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Fei Yu,1,* Ya-min Xiong,1,* Song-cheng Yu,1 Lei-liang He,1 Shan-shan Niu,1 Yu-ming Wu,1 Jie Liu,1 Ling-bo Qu,2 Li-e Liu,1 Yong-jun Wu1 1College of Public Health, 2College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan, People’s Republic of China *These authors contributed equally to this work Background: DNA methyltransferase 1 (DNMT1), a dominant enzyme responsible for the transfer of a methyl group from the universal methyl donor to the 5-position of cytosine residues in DNA, is essential for mammalian development and closely related to cancer and a variety of age-related chronic diseases. DNMT1 has become a useful biomarker in early disease diagnosis and a potential therapeutic target in cancer therapy and drug development. However, till now, most of the studies on DNA methyltransferase (MTase) detection have focused on the prokaryote MTase and its activity.Methods: A magnetic fluorescence-linked immunosorbent assay (FLISA) using CdSe/ZnS quantum dots as fluorescent probes was proposed for the rapid and sensitive detection of the DNMT1 level in this study. Key factors that affect the precision and accuracy of the determination of DNMT1 were optimized.Results: Under the optimal conditions, the limit of detection was 0.1 ng/mL, the linear range was 0.1–1,500 ng/mL, the recovery was 91.67%–106.50%, and the relative standard deviations of intra- and inter-assays were respectively 5.45%–11.29% and 7.03%–11.25%. The cross-reactivity rates with DNA methyltransferases 3a and 3b were only 4.0% and 9.4%, respectively. Furthermore, FLISA was successfully used to detect the levels of DNMT1 in human serum samples, and compared with commercial enzyme-linked immunosorbent assay (ELISA) kits. The results revealed that there was a good correlation between FLISA and commercial ELISA kits (correlation coefficient r=0.866, p=0.001). The linear scope of FLISA was broader than ELISA, and the measurement time was much shorter than ELISA kits.Conclusion: These indicated that the proposed FLISA method was sensitive and high throughput and can quickly screen the level of DNMT1 in serum samples. Keywords: DNA methyltransferase 1, quantum dots, fluorescence immunoassay, magnetic carboxyl beads, high throughput, serum sample

Encapsulation of transition metals represents a crucial method for modifying the electronic structure and regulating the reactivity of fullerene, thereby expanding its applications. Herein, we present calculations with density functional theory methods to investigate the mechanisms of the Diels-Alder (DA) reactions of cyclopentadiene and La@C 60 or Gd@C 60 as well as their tricationic derivatives. Our findings indicate that the encapsulation of La and Gd into the C 60 cage is thermodynamically favorable. The DA reactions are favored by the presence of La and Gd, with lower barriers, though the regioselectivity, favoring 6-6 bonds in the fullerene, is not affected. The effect of external electric fields has been also considered., (© 2024 Wiley-VCH GmbH.)

In this study, the liquid culture system of Pleurotus nebrodensis mycelium with high yield were established by using orthogonal experiments. Results indicated a 58.08 % increase in mycelium biomass and a 2.22 % increase in polysaccharide content after condition optimization. Experiments showed that the extracted polysaccharides have significant antioxidant and anti-exercise fatigue activities. They could effectively scavenge DPPH, ABTS, hydroxyl free radicals and superoxide anaion, prolong weight-loaded swimming time in mice, reduce levels of MDA, LD, and LDH in serum, enhance SOD activity, as well as increase hepatic and muscle glycogen reserves. The mechanism may be attributed to the activation of the Nrf2/Keap1 signaling pathway, inhibition of oxidative stress, and subsequent exerting anti-fatigue effects. The results in this work provides new avenue for easily accessible natural polysaccharide resources with a very convenient approach, which is beneficial for the development of anti-fatigue functional foods for public consumption., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The development of stable fluorescent sensors for toxic pollutants and drugs is meaningful to the environment and public health. In this work, nitrogen-doped graphene quantum dots (N-GQDs) were facially synthesized by a one-step hydrothermal method using soluble starch and l-arginine as carbon and nitrogen sources in pure water at 190 °C for 4 h. The as-synthesized N-GQDs were well characterized and displayed blue fluorescence emission at 445 nm with excellent pH stability, salt tolerance, thermostability, photobleaching resistance and reproducibility. Moreover, N-GQDs could serve as an "on-off" sensor for selective detection of Cr(vi) and folic acid with low detection limit (0.80 and 2.1 μM), good linear correlation over wide linear range (0-50 μM and 0-200 μM) as well as short response time (<10 s). The practical applications of N-GQDs for Cr(vi) and folic acid detection in actual samples were further investigated and showed acceptable recoveries (92-105%) with relative standard deviations less than 5%. These results indicated that this N-GQDs-based sensor could be a potential alternative for Cr(vi) and folic acid detection in the fields of environmental monitoring and drug analysis., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The field of artificial photosynthesis, which focuses on harnessing solar light for the conversion of CO 2 to economically valuable chemical products, remains a captivating area of research. In this study, we developed a series of photocatalysts based on Earth abundant elements (Fe, Co, Ni, Cu, and Zn) incorporated into 2D metalloporphyrin-conjugated organic polymers known as MTBPP-BEPA-COPs. These photocatalysts were utilized for the photoreduction of CO 2 employing only H 2 O as the electron donor, without the need for any sacrificial agents or precious-metal cocatalysts. Remarkably, all of the synthesized MTBPP-BEPA-COPs exhibited an exceptional CO 2 photoreduction performance only irradiated by visible light. Particularly, upon optimizing the metal ion coordinated with porphyrin units, ZnTBPP-BEPA-COP outperformed the other MTBPP-BEPA-COPs in terms of photocatalytic activity, achieving an impressive CO reduction yield of 152.18 μmol g -1 after just 4 h of irradiation. The electrostatic potential surfaces calculated by density functional theory suggest the potential involvement of metal centers as binding and catalytic sites for the binding of CO 2 . The calculated adsorption energy of CO 2 with ZnTBPP-BEPA-COP exhibited one of the two smallest values. This may be the reason for the excellent catalytic effect of ZnTBPP-BEPA-COP. Thus, the present study not only demonstrates the potential of porphyrin-based conjugated polymers as highly efficient photocatalysts for CO 2 reduction but also offers valuable insights into the rational design of such materials in the future.

Lycium ruthenicum Murray possesses significant applications in both food and medicine, including antioxidative, anti-tumor, anti-fatigue, anti-inflammatory, and various other effects. Consequently, there has been a surge in research endeavors dedicated to exploring its potential benefits, necessitating the organization and synthesis of these findings. This article systematically reviews the extraction and content determination methods of active substances such as polysaccharides, anthocyanins, flavonoids, and polyphenols in LRM in the past five years, as well as some active ingredient composition determination methods, biological activities, and product development. This review is divided into three main parts: extraction and determination methods, their bioactivity, and product development. Building upon prior research, we also delve into the economic and medicinal value of Lycium ruthenicum Murray, thereby contributing significantly to its further exploration and development. It is anticipated that this comprehensive review will serve as a valuable resource for advancing research on Lycium ruthenicum Murray.

In recent years, seeking and screening of compounds that can inhibit and/or depolymerize protein aggregation has been a hot issue in the field of pharmaceutical research. As a new material, quantum dots have been widely concerned by medical researchers. In present study, a novel 4-mercaptophenylboronic acid functionalized MoS 2 quantum dots (4-MPBA-MoS 2 QDs) was successfully synthesized through a one-pot hydrothermal approach by using molybdate dehydrate and 4-mercaptophenylboronic acid as Mo and S source, respectively. Transmission electron microscopy observation showed that the morphology and microstructure of the 4-MPBA-MoS 2 QDs displayed uniform spherical shape with a diameter of approximately 1.5 ∼ 3.0 nm. The UV and fluorescence spectra experiments indicated that the prepared QDs had good water solubility and two weak absorption peaks were appeared at 280 nm and 310 nm. When the excitation wavelength was set to 310 nm, the 4-MPBA-MoS 2 QDs had the strongest fluorescence intensity, and the maximum emission wavelength appeared at 405 nm. In vitro experiments showed that the 4-MPBA-MoS 2 QDs could significantly reduce the aggregation of bovine serum albumin (BSA). Especially when the mass ratio of BSA to 4-MPBA-MoS 2 QDs was 1:5, the inhibition rate could reach 76.4%. Cell experiment showed that the presence of 4-MPBA-MoS 2 QDs could obviously decrease the cytotoxicity induced by BSA amyloid fibrils. Moreover, the depolymerization of BSA amyloid fibrils by 4-MPBA-MoS 2 QDs and its excellent cell permeability were also observed. Molecular docking studies have shown that 4-MPBA-MoS 2 QDs may stabilize the BSA structure through van der Waals forces, hydrophobic force, electrostatic interactions and hydrogen bonds formed between the outer layer of 4-MPBA and BSA to prevent fibrosis aggregation. The results of this study suggested that 4-MPBA-MoS 2 QDs showed low cytotoxicity, good biocompatibility and solubility, and had a great potential in the design of new drugs for the treatment of amyloid-related diseases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Although membrane separation technology has been widely used in the treatment of oily wastewater, the complexity and high cost of the membrane preparation, as well as its poor stability, limit its further development. In this study, via the vacuum-assisted suction filtration method, polydopamine (PDA)-coated TiO 2 nanoparticles were tightly attached and embedded on both sides of laboratory filter paper (FP). The resultant FP possessed the typical wettability of high hydrophilicity in the air with the water contact angle (WCA) of 28°, superoleophilicity with the oil contact angle (OCA) close to 0°, underwater superoleophobicity with the underwater OCA greater than 150°, and superhydrophobicity under the water with the underoil WCA over 150° for five kinds of organic solvents (carbon tetrachloride, toluene, n-hexane, n-octane, and iso-octane). The separation efficiency of immiscible oil/water, oil-in-water, and water-in-oil emulsions using the modified FP is higher than 99%. After 17 cycles of emulsion separation, a high separation efficiency of 99% was still maintained for the FP, along with good chemical and mechanical stability. In addition, successful separation and purification were also realized for the oil-in-water emulsion that contained the methylene blue (MB) dye, along with the complete degradation of MB in an aqueous solution under UV irradiation.

In this work, a 2-(2'-hydroxyphenyl)benzimidazole derived fluorescent probe, 2-(2'-hydroxy-4'-aminophenyl)benzimidazole (4-AHBI), was synthesized and its fluorescent behavior toward triphosgene were evaluated. The results showed that 4-AHBI exhibited high sensitivity (limit of detection, 0.08 nM) and excellent selectivity for triphosgene over other acyl chlorides including phosgene in CH 2 Cl 2 solution. Moreover, 4-AHBI loaded test strips were prepared for the practical sensing of triphosgene., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A visible-light-induced persulfate-promoted cascade phosphorylation/cyclization reaction to access various phosphorylated pyrrolo[1,2- a ]indolediones under mild conditions was developed. Notably, the transformation was carried out with diethyl carbonate/H 2 O as a green medium at room temperature. More impressively, traditional metal catalysts and photocatalysts could be effectively avoided. The reactions are simple to operate, easy to scale up, and have good functional group tolerance.

3-(2-(Ethynyl)phenyl)quinazolinones were designed and synthesized as a class of novel and efficient skeletons for phosphorylation/cyclization reactions. Under visible light irradiation, a series of phosphorylated quinolino[2,1- b ]quinazolinones (35 examples, up to 87% yield) were first synthesized from 3-(2-(ethynyl)phenyl)quinazolinones and diarylphosphine oxides by using 4CzIPN as a photocatalyst under mild conditions. This reaction was also applicable under sunlight irradiation. Moreover, the reaction efficiency could be significantly improved under continuous-flow conditions.

In this work, the antibacterial activity and mechanism of chloroform fraction obtained from aqueous extract of mugwort leaves against Staphylococcus aureus were investigated. The extract showed obvious antibacterial activity against S. aureus which the minimum inhibitory concentration and minimum bactericidal concentration were determined to be 3·0 and 6·0 mg ml -1 respectively. The mechanism study suggested that the extract could destroy the integrity of the S. aureus cell walls and increase the permeability of cell membrane in a certain concentration, but it could not kill S. aureus in a short time. Instead, the extract could make bacteria in a state of apoptosis for a long time, interfere with the normal physiological metabolism of bacteria, and eventually make bacteria die, which was confirm by scanning electronic microscope., (© 2022 The Society for Applied Microbiology.)

A photoexcited sulfenylation of C(sp 3 )-H bonds in amides is developed for the synthesis of sulfenyl amides using thiosulfonates as a sulfur source. In the presence of easily available and inexpensive Na 2 -eosin Y, TBHP and K 2 CO 3 , various sulfenyl amides can be obtained under the irradiation of blue light at room temperature.

1-Acryloyl-2-cyanoindoles were found to be novel and efficient skeletons in visible-light-induced persulfate-promoted cascade cyclization reactions. With this transition-metal-free photocatalytic procedure, various sulfonated/thiocyanated pyrrolo[1,2- a ]indolediones were synthesized from 1-acryloyl-2-cyanoindoles with sulfonyl hydrazides/NH 4 SCN at room temperature under mild reaction conditions.

The Ce(III)-photocatalyzed synthesis of amides from carboxylic acids and aryl isocyanates was developed. The reaction includes the formation of alkyl radicals from carboxylic acids followed by radical addition to the electron-deficient carbon of isocyanate.

In present study, a novel glutathione functionalized MoS 2 quantum dots (GSH-MoS 2 QDs) was synthesized from sodium molybdate dehydrate and glutathione by using a one-pot hydrothermal method. After they were characterized, the influence of GSH-MoS 2 QDs on amyloid aggregation of bovine serum albumin (BSA) was investigated by various analytical methods including thioflavin T fluorescence assay, circular dichroism and transmission electron microscope. Moreover, the effect of GSH-MoS 2 QDs on cytotoxicity induced by BSA amyloid fibrils and cell penetration were evaluated by MTT assay and confocal fluorescence imaging, respectively. The results indicated that the GSH-MoS 2 QDs not only had good water solubility, excellent biocompatibility and low cytotoxicity, but also could obviously inhibit the aggregation of BSA and depolymerize the formed BSA aggregates. The data obtained from this work demonstrated that the GSH-MoS 2 QDs is expected to become a candidate drug for the treatment of amyloid-related diseases., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A practical synthetic route to construct a variety of 3-benzyl spiro[4,5]trienones was developed via transition-metal Cu/Ag-catalyzed oxidative ipso -annulation of activated alkynes with unactivated toluenes using TBPB as an oxidant under microwave irradiation. This method allows the formation of two carbon-carbon bonds and one carbon-oxygen bond in a single reaction through a sequence of C-H oxidative coupling, ipso -carbocyclization and dearomatization. The advantages of this protocol are its operational simplicity and broad substrate scope, and the ability to afford the desired products in moderate to good yields.

The mechanistic understanding of catalytic radical reactions currently lags behind the flourishing development of new types of catalytic activation. Herein, an innovative single electron transfer (SET) model has been expanded by using the nonadiabatic crossing integrated with the rate-determining step of 1,5-hydrogen atom transfer (HAT) reaction to provide the control mechanism of radical decay dynamics through calculating excited-state relaxation paths of a paradigm example of the amide-directed distal sp 3 C-H bond alkylation mediated by Ir-complex-based photocatalysts. The stability of carbon radical intermediates, the functional hindrance associated with the back SET, and the energy inversion between the reactive triplet and closed-shell ground states were verified to be key factors in improving catalytic efficiency via blocking radical inhibition. The expanded SET model associated with the dynamic behaviors and kinetic data could guide the design and manipulation of visible-light-driven inert bond activation by the utilization of photocatalysts bearing more or less electron-withdrawing groups and the comprehensive considerations of kinetic solvent effects and electron-withdrawing effects of substrates.

A general visible-light-promoted metal-free synthesis of secondary and tertiary thiocarbamates starting from thiosulfonates and N -substituted formamides is developed. By employing rhodamine B as a photocatalyst and tert -butyl hydroperoxide (TBHP) as an oxidant, a wide scope of thiocarbamates can be obtained through direct thiolation of acyl C-H bonds under irradiation of blue light at room temperature for 12 h.

A visible-light-induced decarboxylation reaction was developed for the synthesis of alkylated benzimidazo[2,1- a ]isoquinoline-6(5 H )-ones and indolo[2,1- a ]isoquinolin-6(5 H )-ones under metal-free conditions. Impressively, metal catalysts and traditionally volatile organic solvents could be effectively avoided.

A general and metal-free visible-light-induced decarboxylative arylation procedure at room temperature was described for the construction of acylated heterocyclic derivatives, such as benzimidazo/indolo[2,1- a ]isoquinolin-6(5 H )-ones, aroylazaspiro[4.5]trienones, thioflavones, and so on. This practical arylation procedure was conducted by using 2,4,5,6-tetra(9 H -carbazol-9-yl)isophthalonitrile (4CzIPN) as a photocatalyst under mild conditions, which avoided the use of an additional base, traditional heating, and metal reagents.

Resveratrol and oxyresveratrol are two natural polyhydroxy trans-stilbene products. Previous studies have shown that both of them can effectively inhibit the activity of tyrosinase. However, little attention has been paid to study the difference of their inhibitory mechanism. To reveal this difference, in this work a comparative study on the inhibitory effects of resveratrol and oxyresveratrol against cellular tyrosinase activity and melanin content were investigated by B16F0 cells, and the inhibitory mechanism of them on tyrosinase was revealed by cell-free tyrosinase inhibition, intrinsic fluorescence spectrum, circular dichroism and molecular docking. The results showed that the inhibitory capacity of oxyresveratrol toward tyrosinase activity and melanin formation was better than that of resveratrol. The difference of their inhibitory mechanism may be closely related to the different types of inhibition, the different strength of their interaction with tyrosinase and the different number of hydrogen bonds between them. The data in this study provide a scientific basis for revealing the inhibitory mechanisms of resveratrol and oxyresveratrol toward tyrosinase, and lay an experimental foundation for further development and utilization of them., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this work, an ESIPT-based fluorescence probe, 5'-amino-2-(2'-hydroxyphenyl)benzimidazole (P1), was synthesized and explored for the ratiometric detection of phosgene. Compared to 2-(2'-hydroxyphenyl)benzimidazole (HBI), P1 exhibits high sensitivity (LoD = 5.3 nM) and selectivity toward phosgene with the introduction of the amine group. Furthermore, simple P1 loaded test papers are manufactured and display selective fluorescent detection of phosgene in the gas phase., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Weaning is the gradual process of introducing solids or semisolid foods into an infant's diet, in order to ensure their healthy growth. This study developed two kinds of formula weaning food based on roasted or extruded quinoa and millet flour, and evaluated their quality. A fructo-oligosaccharide (FOS)/galacto-oligosaccharide (GOS) mix was added to provide the prebiotic potential. The protein contents of the roasted quinoa-millet complementary food (RQMCF) and extruded quinoa-millet complementary food (EQMCF) were 16.7% and 17.74% higher, respectively, than that of commercial millet complementary food (CMCF). Both RQMCF and EQMCF provided sufficient levels of energy and minerals. Extrusion provided the foods with a lower viscosity, and higher solubility and water absorption ability than roasting. In vitro digestion results showed that EQMCF exhibited the highest starch and protein digestibility (89.76% and 88.72%, respectively) followed by RQMCF (87.75% and 86.63%) and CMCF (83.35% and 81.54%). The digestas of RQMCF and EQMCF after in vitro digestion exhibited prebiotic effects by promoting the growth of the probiotics (Lactobacillus plantarum and Lactobacillus delbrueckii). These results will contribute to developing complementary weaning foods for infants. PRACTICAL APPLICATION: This study has shown that extrusion is an efficient and stable processing method for producing infant complementary foods with low density, balanced nutrition, and high levels of starch and protein digestibility. Extruded quinoa-millet prebiotic complementary food can also promote the proliferation of probiotics. This will provide a new direction for developing novel infant formula weaning foods., (© 2021 Institute of Food Technologists®.)

In the presence of multiple electrophiles, the reaction sequence is a critical mechanistic problem. Here, we report a theoretical study on the mechanism of phosphine-catalyzed [8+2] cycloaddition of heptafulvenes and allenoate. DFT calculations showed that electrophilicity is the barrier for nucleophilic attack, while it fails in the prediction of priority.

2,4,5,6-Tetrakis(3,6-di- tert -butyl-9 H -carbazol-9-yl)isophthalonitrile (4CzIPN- t Bu) was developed as a photocatalyst for the phosphorus-radical-initiated cascade cyclization reaction of isocyanides. By using 4CzIPN- t Bu as catalyst, we developed a visible-light-induced proton-coupled electron transfer strategy for the generation of phosphorus-centered radicals, via which a wide range of phosphorylated phenanthridines, quinolines, and benzothiazoles were successfully constructed.

Targeted release of anticancer drugs to tumor sites has a pivotal role in clinical oncology. pH-responsive drug delivery systems, with an intelligent and targeted release of anticancer drugs in a controllable manner based on sensitivities to the weakly acidic environments of tumor cellular microenvironments, are desirable. Herein, the design of such a pH-responsive drug delivery system is detailed using in situ amino-functionalized hollow mesoporous silica nanoparticles as carriers. The drug release behavior of the pH-responsive delivery system was evaluated under an in vitro simulation of tumor cellular microenvironments. The drug delivery system has efficient drug loadings and targeted release. Zorubicin hydrochloride releasing percentage is almost up to 100% at a buffer pH of 5.0. The drug release systems described demonstrating great potential in anticancer therapy., Competing Interests: The authors declare no competing financial interest., (© 2020 The Authors. Published by American Chemical Society.)

A metal-free and base-free procedure for the phosphorylation of imidazo[1,2- a ]pyridines with phosphine oxides under the irradiation of visible light at room temperature in green solvent was reported, featuring mild and sustainable conditions, convenient operation, as well as good functional group compatibility.

A taxonomic identification using a polyphasic approach was performed on strain NBS58-1 T , which was isolated from the interfacial sediment of Taihu Lake in China. Strain NBS58-1 T was Gram-stain-negative, aerobic, non-spore-forming and catalase-positive. Phylogenetic analyses based on 16S rRNA gene and three housekeeping genes ( rpoB , gyrB and dnaK ) sequences supported the position that strain NBS58-1 T should be classified within the genus Rufibacter . The 16S rRNA gene sequence of strain NBS58-1 T possessed the highest similarity to Rufibacter sediminis H-1 T (96.60 %), followed by Rufibacter glacialis MDT1-10-3 T (96.17 %). And the ANI value between strain NBS58-1 T and R. glacialis MDT1-10-3 T was 79.3 %. The respiratory quinone was menaquinone 7 (MK-7). The major cellular fatty acids comprised iso-C 15 : 0 and summed feature 3. Phosphatidylethanolamine, two unidentified phospholipids and four unidentified lipids were the main polar lipids. The genomic DNA G+C content was 51.3 mol%. Based on phenotypic features and phylogenetic position, a novel species with the name Rufibacter hautae sp. nov. is proposed. The type strain is NBS58-1 T =(KACC 21309 T =MCCC 1K04037 T ). We also proposed Rufibacter quisquiliarum as a latter heterotypic synonym of Rufibacter ruber .

A feasible arylaminomethyl radical-triggered tandem annulation reaction has been developed toward a large variety of poly fused heterocycles, tetrahydroimidazo[1,5- a ]quinoxalin-4(5 H )-ones, by reacting diverse quinoxalin-2(1 H )-ones with various N -arylglycines in green solvent (DMC) in the presence of CsPbBr 3 under white-light irradiation conditions.

A novel strain, designated NS18 T , was isolated from sediment sampled at Taihu Lake, PR China. Cells of the isolate were spherical, aerobic, non-motile, Gram-stain-positive and non-endospore-forming. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NS18 T clustered in a clade of the genus Agrococcus . Its closest phylogenetic neighbour was Agrococcus lahaulensis DSM 17612 T with 98.2 % 16S rRNA gene sequence similarity. The complete genome of NS18 T was 2 736 037 bp and its genomic DNA G+C content was 72.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain NS18 T and A. lahaulensis DSM 17612 T based on their whole genomes were 85.1 and 28.7 %, respectively. The major fatty acids were anteiso-C 17 : 0 and anteiso-C 15 : 0 . The predominant menaquinones were MK11 and MK12. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol and two unidentified lipids. The components of the peptidoglycan were Ala, Gly, Asp, Thr and DAB. The whole-cell sugars contained rhamnose, ribose, xylose and glucose. According to the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain NS18 T (=NBRC 113859 T =MCCC 1K03759 T ) represents a novel species, for which the name Agrococcus sediminis sp. nov is proposed.

In this study, the effect of a glycoprotein obtained from Fupenzi (FPZ) (Rubus chingii Hu.) on the fibrillation of bovine serum album (BSA) was investigated by multi-spectroscopic methods and transmission electron microscopy. Moreover, the cytotoxicity of the glycoprotein and the effect of it on H 2 O 2 -induced cell viability were investigated by cell counting kit and β-galactosidase kit, respectively. The experimental results indicated that the glycoprotein showed very low toxicity to NRK-52E cells and could obviously delay cell senescence and improve cell viability. Moreover, the glycoprotein could effectively inhibit the formation of BSA fibrils and destroy the stability of preformed BSA fibrils in a concentration-dependent manner. Generally, antioxidant capacities are thought to be related to the anti-amyloidogenic activity of inhibitors; therefore, to reveal the inhibitory mechanism, the anti-oxidative property of the glycoprotein was examined by DPPH and ABTS assays. The results demonstrated that FPZ glycoprotein had a remarkable antioxidant activity and the IC 50 values of DPPH and ABTS were 0.249 mg mL -1 and 0.092 mg mL -1 , respectively. This work suggested that the FPZ glycoprotein had the potential to be designed a new therapeutic agent for attenuating aging and preventing the age-related diseases., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The possible mechanisms and origin of selectivities in N-heterocyclic carbene (NHC)-catalyzed reactions of an aliphatic ester with aminochalcone were studied using density functional theory. Herein, a general mechanistic map involving various types of possible intermediates was discovered, and the corresponding chemoselective pathways were systematically investigated. Based on the computational results, the most energetically favorable reaction pathway mainly involved in the following processes: formation of a homoenolate intermediate via α/β-H elimination, formal Michael addition of a homoenolate intermediate to aminochalcone, intramolecular aldol-type reaction, and ring closure to form the lactam product. Furthermore, the formal Michael addition process was shown to be the stereoselectivity-determining step, generating the RR-configured product preferentially. The chemoselectivity was successfully predicted by comparing the ω + N index of reacting ability for a nucleophile (N) and electrophile (E). This work would provide a general guideline for predicting chemoselectivity in NHC-catalyzed reactions.

Generally, N-heterocyclic carbene (NHC) complexed with carbonyl compounds would transform into several important active intermediates, i.e. , enolates, Breslow intermediates, or acylazolium intermediates, which act as either a nucleophile (Nu) or an electrophile (E) to react with the other E/Nu partner. Hence, the key to predicting the origin of chemoselectivity is to compute the activity ( i.e. , electrophilic index ω for E and nucleophilic index N for Nu) and stability of the intermediates and products, which are suggested in a general mechanistic map of these reactions. To support this point, we selected and studied different cases of the NHC-catalyzed reactions of carbonyl compounds in the presence of a base and/or an oxidant, in which multiple possible pathways involving acylazolium, enolate, Breslow, and α,β-unsaturated acylazolium intermediates were proposed and a novel index ω + N of the E and Nu partners was employed to exactly predict the energy barrier of the chemoselective step in theory. This work provides a guide for determining the general principle behind organocatalytic reactions with various chemoselectivities, and suggests a general application of the reaction index in predicting the chemoselectivity of the nucleophilic and electrophilic reactions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A mixture of pathways including the use of catalyst was proposed for a dirhodium-mediated triazole activation-cycloaddition. This proposal was supported by the results of density functional theory (DFT) calculations, and was indicated to involve a non-catalyzed cleavage of the triazole N-N bond followed by a dirhodium-assisted denitrogenation. Electron-deficient carboxylates were found to be favourable for the rate-determining denitrogenation step.

A silver-catalyzed efficient and direct C-H carbamoylation of quinolines with oxamic acids to access carbamoylated quinolines has been developed through oxidative decarboxylation reaction. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance and excellent yields under mild conditions.

Any solid surface with homogenous or varying surface energy can spontaneously show variable wettability to liquid droplets with different or identical surface tensions. Here, we studied a glass slide sprayed with a quasi-superamphiphobic coating consisting of a hexane suspension of perfluorosilane-coated nanoparticles. Four areas on the glass slide with a total length of 7.5 cm were precisely tuned via ultraviolet (UV) irradiation, and droplets with surface tensions of 72.1-33.9 mN m -1 were categorized at a tilting angle of 3°. Then, we fabricated a U-shaped device sprayed with the same coating and used it to sort the droplets more finely by rolling them in the guide groove of the device to measure their total rolling time and distance. We found a correlation between ethanol content/surface tension and rolling time/distance, so we used the same device to estimate the alcoholic strength of Chinese liquors and to predict the surface tension of ethanol aqueous solutions.

An aerobic, Gram-stain-negative, non-spore-forming and rod-shaped bacterial strain, designated N8 T , was isolated from the interfacial sediment of Taihu Lake in PR China. The strain formed white to blue colonies on R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain N8 T represented a member of the genus Gemmobacter and was most closely related to Gemmobacter aquaticus A1-9 T (97.97 %). The average nucleotide identity and digital DNA-DNAhybridization values between strain N8 T and G. aquaticus A1-9 T based on their whole genomes were 78.8 and 21.7 %, respectively. Q-10 was the main predominant ubiquinone. The major fatty acids were summed feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c ), C 18 : 0 and C 16 : 0 . The G+C content of the genomic DNA was 66.1 mol%. The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, two unidentified glycolipids and two unidentified lipids. Based on its physiological, biochemical and chemotaxonomic characteristics, strain N8 T represents a novel species of the genus Gemmobacter , for which the name Gemmobacter caeruleus sp. nov. is proposed. The type strain is N8 T =(KACC 21307 T =MCCC 1K04036 T ).

A novel bacterial strain, designated NS28 T , was isolated from interfacial sediment sampled at Taihu Lake, PR China. Cells were rod-shaped, Gram-negative, aerobic and non-motile on Reasoner's 2A medium. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NS28 T was most closely related to species from the genus Dyadobacter , with 98.4 and 96.0 % 16S rRNA gene sequence similarity to its closest phylogenetic neighbours Dyadobacter sediminis CGMCC 1.12895 T and Dyadobacter luticola CCTCC AB 2017091 T , respectively. MK-7 was the only cellular menaquinone. The major fatty acids were summed feature 3 (C 16 : 1 ω7 c and/or C 16 : 1 ω6 c ), iso-C 15 : 0 and C 16 : 1 ω5 c . The major polar lipids were phosphatidylethanolamine, one phospholipid, one aminolipid, one lipid and two unidentified lipids. Genomic analysis of strain NS28 T indicated that the total genome size was 6 477 094 bp with a G+C content of 44.8 mol%, 5380 protein-coding genes, 79 contigs and an N50 length of 299584 bp. On the basis of the genomic DNA sequence, the average nucleotide identity values were 90.5 and 74.1 % with D. sediminis CGMCC 1.12895 T and D. luticola CCTCC AB 2017091 T , respectively. Digital DNA-DNA hybridization results of strain NS28 T with D. sediminis CGMCC 1.12895 T and D. luticola CCTCC AB 2017091 T were 40.9 and 18.6 %, respectively. Based on the phenotypic, chemotaxonomic, phylogenetic and genome sequence data presented here, it is proposed that strain NS28 T represents a novel species of the genus Dyadobacter for which the name Dyadobacter flavalbus is proposed . The type strain is NS28 T (=NBRC 113854 T =MCCC 1K03764 T ).

Aggregation-induced emission luminogens (AIEgens) with a large electron donor and acceptor (D-A) conjugated system have been widely used in the development of organic light emitting diodes (OLEDs), chemosensors, and bioimaging materials due to their excellent properties such as high quantum yields, long emission wavelengths, controllable luminescence lifetimes, and nonlinear optics (NLO) properties. However, most of the AIE materials have been derived from limited classic AIE cores such as tetraphenylethene (TPE) and tetraphenylpyrazine (TPP), and thus, tedious syntheses or later modifications toward those AIEgens have always been unavoidable. In this report, a type of atypical AIEgens (designated as ASIQs) composed of large conjugated structures with a natural electron D-A system is disclosed, which shows large Stokes shifts, high photostabilities, excellent cell permeabilities, low biotoxicities, and good two-photon excited capacities, making them suitable for applications of one-photon/two-photon targeted imaging in live cells. In short, this work offers a type of atypical AIEgens which will possibly become an ideal platform leading to more structurally diverse and functionally excellent AIE-based luminescent materials.

The introduction of phosphorus functional groups into the skeleton of thioflavones is an attractive task and of great significance. Herein, a metal-free visible-light-induced radical cascade cyclization was developed for the preparation of 2-phosphorylated thioflavones from methylthiolated alkynones and phosphine oxides. In water as a green reaction medium, a large number of such 2-phosphorylated thioflavones were prepared, catalyzed by 4CzIPN [1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene] under visible-light irradiation. These reactions could be performed at ambient temperature and feature simple operation, wide reaction scope, and recyclability of aqueous media., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A practical and efficient synthetic route to construct a variety of 3-amidated quinoxalin-2(1H)-ones was developed via transition-metal free direct oxidative amidation of quinoxalin-2(1H)-ones with amidates using Selectfluor reagent as a mild oxidant. This protocol features mild reaction conditions, operational simplicity, broad substrate scope, and good to excellent yields.

A metal-free cascade reaction was developed for the synthesis of indolo[1,2-a]quinoline derivatives from arylsulfonyl hydrazides and 1-(2-(arylethynyl)phenyl)indoles in the presence of TBAI/TBHP. Impressively, these products exhibit excellent fluorescence properties, which is promising for cell imaging.

As a new type of bifunctional catalyst, the Lewis acid transition-metal (LA-TM) catalysts have been widely applied for hydrogen activation. This study presents a mechanistic framework to understand the LA-TM-catalyzed H 2 activation through DFT studies. The mer(trans)-homolytic cleavage, the fac(cis)-homolytic cleavage, the synergetic heterolytic cleavage, and the dissociative heterolytic cleavage should be taken as general mechanisms for the field of LA-TM catalysis. Four typical LA-TM catalysts, the Z-type κ 4 -L 3 B-Rh complex tri(azaindolyl)borane-Rh, the X-type κ 3 -L 2 B-Co complex bis-phosphino-boryl (PBP)-Co, the η 2 -BC-type κ 3 -L 2 B-Pd complex diphosphine-borane (DPB)-Pd, and the Z-type κ 2 -LB-Pt complex (boryl)iminomethane (BIM)-Pt are selected as representative models to systematically illustrate their mechanistic features and explore the influencing factors on mechanistic variations. Our results indicate that the tri(azaindolyl)borane-Rh catalyst favors the synergetic heterolytic mechanism; the PBP-Co catalyst prefers the mer(trans)-homolytic mechanism; the DPB-Pd catalyst operates through the fac(cis)-homolytic mechanism, whereas the BIM-Pt catalyst tends to undergo the dissociative heterolytic mechanism. The mechanistic variations are determined by the coordination geometry, the LA-TM bonding nature, the electronic structure of the TM center, and the flexibility or steric effect of the LA ligands. The presented mechanistic framework should provide helpful guidelines for LA-TM catalyst design and reaction developments., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Previously reported copper oxide-based cathodic photoelectrochemical bioanalysis of cysteine had attributed the decrease of the photocurrents to the binding of cysteine onto the CuO surface. However, our latest investigation found that the previous explanation was not correct. This Letter presents the in-depth study of such phenomena and a new insight into the underlying mechanism. Specifically, the unique redox reaction between the CuO photocathode and cysteine produced [Cys-Cu(I)] and cystine, and the insoluble complex blocked the partial contact between the photoelectrode and the dissolved O 2 -containing electrolyte and reduced the effective working area of the photocathode, leading to the decrease of photocurrent.

A novel and practical fluoroalkyl radical-initiated cascade reaction was developed to access diverse 2-fluoroalkylbenzothiazoles by reacting various fluoroalkyl radical sources, including perfluoroalkyl iodide (IC n F 2 n+1 , n = 3-8, 10), ICF(CF 3 ) 2 , ICF 2 COOEt, ICF 2 CF 2 Cl, or ICF 2 CF 2 Br, tetramethylethane-1,2-diamine (TMEDA), and 2-isocyanoaryl thioethers in tetrahydrofuran under nitrogen atmosphere and blue-light irradiation conditions. Furthermore, this one-pot protocol could well be expanded to access various 2-fluoroalkylbenzoselenazoles starting from (2-isocyanophenyl)(methyl)selane, perfluoroalkyl iodides (IC n F 2 n+1 , n = 3-8) or ICF 2 COOEt and TMEDA.

The possible mechanisms and origin of the enantioselectivity of the reaction between 2H-azirine and an aldehyde catalyzed by an N-heterocyclic carbene (NHC) were theoretically studied and predicted at the M06-2X/6-31G(d,p)/IEF-PCM MTBE //M06-2X-GD3/6-311++G(2df, 2pd)/IEF-PCM MTBE level. The most favorable reaction pathway consists of four steps, i.e., complexation of the NHC and the aldehyde, stepwise [1,2]-proton transfer, C-C bond formation coupled with another proton transfer, and recycling of the NHC. The computational results indicate that the stereoselectivity-determining step is also the rate-determining step, which is the third step (i.e., intermolecular addition). The calculated 99 % ee is very close to the experimentally observed value of 96 % ee, demonstrating that the calculations are reliable. Two important roles of the NHC were identified by global reaction index (GRI) analysis and natural population analysis (NPA), that is, realizing the umpolung reactivity of the aldehyde and facilitating the deprotonation of aldehyde. Moreover, the efficiency of different NHC catalysts can be mainly predicted by computing the nucleophilic index of the corresponding Breslow intermediates. Furthermore, distortion/interaction and noncovalent interaction (NCI) analyses revealed that the π⋅⋅⋅π interactions between the NHC and substrates were the key factor in the reaction enantioselectivity., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

(1) Background: Rhubarb anthraquinones-a class of components with neuroprotective function-can be used to alleviate cerebral ischemia reperfusion injury. (2) Methods: The three pharmacodynamic indicators are neurological function score, brain water content, and cerebral infarction area; UPLC-MS/MS was used in pharmacokinetic studies to detect plasma concentrations at different time points, and DAS software was used to calculate pharmacokinetic parameters in a noncompartmental model. (3) Results: The results showed that the pharmacodynamics and pharmacokinetics of one of the five anthraquinone aglycones could be modified by the other four anthraquinones, and the degree of interaction between different anthraquinones was different. The chrysophanol group showed the greatest reduction in pharmacodynamic indicators comparing with other four groups where the rats were administered one of the five anthraquinones, and there was no significant difference between the nimodipine group. While the Aloe-emodin + Physcion group showed the most obvious anti-ischemic effect among the groups where the subjects were administered two of the five anthraquinones simultaneously. Emodin, rhein, chrysophanol, and physcion all increase plasma exposure levels of aloe-emodin, while aloe-emodin lower their plasma exposure levels. (4) Conclusions: This experiment provides a certain preclinical basis for the study of anthraquinone aglycones against cerebral ischemia and a theoretical basis for the study of the mechanism of interaction between anthraquinones.

Predicting the chemoselectivity of [2 + 2] cyclizations is an important challenge in organic chemistry. Herein, we provided a valuable case for this issue. Density functional theory calculations were performed to systematically study the possible mechanisms and origin of selectivities for the N-heterocyclic carbene (NHC)-catalyzed oxidative α-C(sp 3 )-H activation of aliphatic aldehydes and the cascade [2 + 2] cycloaddition with ketimines. The [2 + 2] cycloaddition of azolium enolate intermediates to the C═N bond, rather than the C═O bond of ketimine, is revealed to be determined by chemo- and stereoselectivity. By comparing the energy gap between the frontier molecular orbitals (FMOs) of the two reacting parts involved in the [2 + 2] cycloaddition transition states, we propose a new strategy to determine the origin of the reaction chemoselectivity. Moreover, the local nucleophilic index can efficiently predict the active site of ketimines. Further analyses illustrate that NHC can increase the nucleophilicity of aldehydes and the acidity of the α-C(sp 3 )-H bond, and 3,3',5,5'-tetra- tert-butyl diphenoquinone (DQ) acts as an oxidant and promotes α-C(sp 3 )-H bond deprotonation. This work is useful not only for understanding the NHC-catalyzed oxidative [2 + 2] annulation but also for developing new applications of the FMO theory in organocatalytic cyclizations.

In this paper, the inhibitory kinetics of aloe-emodin on the activity of tyrosinase and the inhibitory mechanism have been investigated by using spectroscopic and molecular docking techniques. The results showed that aloe-emodin inhibited tyrosinase activity in a competitive manner. The binding constants, number of binding sites and thermodynamic parameters obtained at different temperature suggested that aloe-emodin spontaneously binds to tyrosinase at one binding site, mainly via electrostatic forces. Analysis by UV-vis absorption (UV), circular dichroism (CD) and molecular docking indicated that aloe-emodin bound directly into the catalytic cavity and that binding of aloe-emodin to tyrosinase induced conformational changes of the enzyme and blocked the catalytic center of the enzyme preventing binding of the substrate, which caused the inhibition of the tyrosinase activity., (Copyright © 2018 Elsevier B.V. All rights reserved.)