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Background: Thiourea is a classical urease inhibitor which is usually used as a positive control, and many N,N'-disubstituted thioureas have been determined as urease inhibitors. However, due to steric hindrance, N,N'-disubstituted thiourea motif could not bind urease as thiourea. On the contrary, N-monosubstituted thiourea with a tiny thiourea motif could theoretically bind into the active pocket as thiourea. Objective: A series of N-monosubstituted aroylthioureas were designed and synthesized for evaluation as urease inhibitors. Methods: Urease inhibition was determined by the indophenol method and IC50 values were calculated using computerized linear regression analysis of quantal log dose-probit functions. The kinetic parameters were estimated via surface plasmon resonance (SPR) and by nonlinear regression analysis based on the mixed type inhibition model derived from Michaelis-Menten kinetics. Results: Compounds b2, b11, and b19 reversibly inhibited urease with a mixed mechanism, and showed excellent potency against both cell-free urease and urease in the intact cell, with IC50 values being 90- to 450-fold and 5- to 50-fold lower than the positive control acetohydroxamic acid, respectively. The most potent compound b11 showed an IC50 value of 0.060 ± 0.004μM against cell-free urease, which bound to urea binding site with a very low KD value (0.420±0.003nM) and a very long residence time (6.7 min). Compound b11 was also demonstrated to have very low cytotoxicity to mammalian cells. Conclusion: The results revealed that N-monosubstituted aroylthioureas bound to the active site of urease as expected, and represent a new class of urease inhibitors for the development of potential therapeutics against infections caused by urease-containing pathogens.

The disposal and management of wheat straw has become a major concern in wheat production countries because of its abundance. The potential of wheat straw as raw biomass could serve as a long-term sustainable resource if the lignocellulose polymer can be degraded efficiently. To break down this complex polymer and enhance the bioavailability of straw, we propose the application of stainless-steel-supported molybdenum carbide as the anode in electrochemical pretreatment. Our results indicate that the type of electrolyte used in electrolysis has a significant impact on the biodegradation efficiency of the polymer. Moreover, the data indicated that lignin was degraded by 7.4% in purified water and 6.2% in a NaOH system compared to the untreated group. The higher cellulose accessibility was confirmed by enzymatic hydrolysis in the NaOH system. The structural traits indicated that the bond energies of biomass lignocellulose were weakened to some extent in both purified water and NaOH systems. In addition, the enzymatic hydrolysis efficiency of straw treated by electrolysis with alkali electrolyte was significantly improved, and the yield of reducing sugar was increased by 17.9% and 116.8%, respectively, compared with those treated by NaOH alone and electrolysis, respectively. The results from our study also provide evidence that stainless-steel-supported molybdenum carbide along with an aqueous alkali (NaOH) can degrade the amorphous cellulose in lignocellulose and improve the bioavailability of straw effectively.

Background: In the past few decades, with the abuse of antibiotics, bacterial resistance has enhanced constantly. More and more super species of bacteria, which are seriously threatening human health, have been discovered. Developing novel antibacterial agents to overcome the drug-resistance is an urgent duty. We all know that blocking the information-transfer of bacterial DNA and RNA is one of the effective ways to inhibit bacterial growth. Therefore, as the indispensable enzyme for DNA replication and transcription, DNA gyrase is one of the important targets for bacterial inhibitors. Accordingly, many inhibitors of DNA gyrase have also been developed. Methods: In this review, to highlight the recent progress in DNA gyrase inhibitors, the study in this field over the past three years (2017-2019) was summarized and organized based on their backbones or core moieties. Both of the subunits of DNA gyrase were taken into consideration. Results: These DNA gyrase inhibitors have been classified based on their backbones or core moieties. After the comparison of the divided 14 categories, we could achieve some clues for future modification. In particular, we found that benzodiazepines and naphthalene heterocycles were the most common structures in the drug design. On the other hand, isopropyl and cyclopropyl have also been used in drug design, which provides more inspiration for the investigations. Except for GSK2140944, which has entered the phase III clinical trial stage, other compounds here were not fully promulgated with their optimal pharmacokinetic activity. Conclusion: We briefly summed up the current situation and future challenges on this topic. Through the discussion of the design strategies and drug effect, we hope that this review can provide a focused direction for future researches.

1,4-disubstituted 1H-1,2,3-triazoles L was successfully synthesised using a catalyst-free click reaction between an internal alkyne and an azide compound. Refluxing click product L and palladium ch...

The bacterial infection that involves antimicrobial resistance is a rising global threat to public health. Chlorine-based water disinfection processes can inactivate antibiotic resistant bacteria. However, at the same time, these processes may cause the release of antibiotic resistance genes into the water as free DNA, and consequently increase the risk to disseminate antibiotic resistance via natural transformation. Presently, little is known about the contribution of residual chlorine affecting the transformation of extracellular antibiotic resistance genes (ARGs). This study investigates whether chloramine and free chlorine promote the transformation of ARGs and how this may occur. We reveal that both chloramine and free chlorine, at practically relevant concentrations, significantly stimulated the transformation of plasmid-encoded ARGs by the recipient Acinetobacter baylyi ADP1, by up to a 10-fold increase. The underlying mechanisms underpinning the increased transformations were revealed. Disinfectant exposure induced a series of cell responses, including increased levels of reactive oxygen species (ROS), bacterial membrane damage, ROS-mediated DNA damage, and increased stress response. These effects thus culminated in the enhanced transformation of ARGs. This promoted transformation was observed when exposing disinfectant-pretreated A. baylyi to free plasmid. In contrast, after pretreating free plasmid with disinfectants, the transformation of ARGs decreased due to the damage of plasmid integrity. These findings provide important insight on the roles of disinfectants affecting the horizontal transfer of ARGs, which could be crucial in the management of antibiotic resistance in our water systems.

Objectives Xanthohumol (XAN) is a unique component of Humulus lupulus L. and is known for its diverse biological activities. In this study, we investigated whether Xanthohumol could ameliorate memory impairment of APP/PS1 mice, and explored its potential mechanism of action. Methods APP/PS1 mice were used for in vivo test and were treated with N-acetylcysteine and Xanthohumol for 2 months. Learning and memory levels were evaluated by the Morris water maze. Inflammatory and oxidative markers in serum and hippocampus and the deposition of Aβ in the hippocampus were determined. Moreover, the expression of autophagy and apoptosis proteins was also evaluated by western blot. Key findings Xanthohumol significantly reduced the latency and increased the residence time of mice in the target quadrant. Additionally, Xanthohumol increased superoxide dismutase level and reduced Interleukin-6 and Interleukin-1β levels both in serum and hippocampus. Xanthohumol also significantly reduced Aβ deposition in the hippocampus and activated autophagy and anti-apoptotic signals. Conclusions Xanthohumol effectively ameliorates memory impairment of APP/PS1 mice by activating mTOR/LC3 and Bax/Bcl-2 signalling pathways, which provides new insight into the neuroprotective effects of Xanthohumol.

Enzyme reaction has been accepted widely in numerous applications owing to the high efficiency and stereo-selectivity, as well as simple preparation by gene engineering. However, the fragility and complex purification process of the enzyme are long-standing problems which limit the large-scale application. One possible solution may be the enzyme immobilization. As one type of porous material with high loading capacity and designable functionality, Metal-Organic Frameworks (MOFs) are ideal choices for the immobilization of enzyme with a considerable interest in recent years. In this study, d-amino acid transaminase (DAT), an important enzyme for industrial synthesis of d-Ala, was covalently immobilized on the surface of a star MOFs material, UiO-66-NH2. Interestingly, we found that the nanoscale hybrid enzyme UiO-66-NH2-Gd-DAT not only maintained the high catalytic efficiency but also got rid of the interference of polluting enzymes, which meant that we could obtain efficient and stereo-selective immobilized enzyme without complex purification process. In general, our findings demonstrated that using UiO-66-NH2 might be a promising strategy to immobilize enzyme and produce effective biocatalyst with high activity and stereo-selectivity.

We recently showed that site-specific incorporation of 2′-modifications or neutral linkages in the oligo-deoxynucleotide gap region of toxic phosphorothioate (PS) gapmer ASOs can enhance therapeutic index and safety. In this manuscript, we determined if introducing substitution at the 5′-position of deoxynucleotide monomers in the gap can also enhance therapeutic index. Introducing R- or S-configured 5′-Me DNA at positions 3 and 4 in the oligodeoxynucleotide gap enhanced the therapeutic profile of the modified ASOs suggesting a different positional preference as compared to the 2′-OMe gap modification strategy. The generality of these observations was demonstrated by evaluating R-5′-Me and R-5′-Ethyl DNA modifications in multiple ASOs targeting HDAC2, FXI and Dynamin2 mRNA in the liver. The current work adds to a growing body of evidence that small structural changes can modulate the therapeutic properties of PS ASOs and ushers a new era of chemical optimization with a focus on enhancing the therapeutic profile as opposed to nuclease stability, RNA-affinity and pharmacokinetic properties. The 5′-methyl DNA modified ASOs exhibited excellent safety and antisense activity in mice highlighting the therapeutic potential of this class of nucleic acid analogs for next generation ASO designs.

A regio- and stereoselective nickel-catalyzed three-component coupling reaction of aldehydes, 1,3-dienes, and alkenylzirconium reagents was realized. The ligand- and additive-free protocol afforded a convenient approach to the synthesis of skipped diene compounds bearing various functionals (e.g., hydroxyl, carbonyl, halide) and heterocyclic groups. The products were readily transformed into structurally diverse polyenes. The utility of this reaction was also demonstrated by the one-pot operation and scale-up preparation.

Most of the ONOO- fluorescent probes have restricted applications because of their aggregation-caused quenching (ACQ) effect, long response time and low fluorescence enhancement. Herein, we developed a novel AIEgen fluorescent probe (PE-XY) based on a benzothiazole and quinolin scaffold with high sensitivity and selectivity for imaging of ONOO-. The results indicated that probe PE-XY exhibited fast response towards ONOO- with 2000-fold enhancement of fluorescence intensity ratio in vitro. Moreover, PE-XY exhibited a relatively high sensitivity (limit of detection: 8.58 nM), rapid response (

As essential biological thiols in organisms, Cys, Hcy, and GSH are closely related to each other, and they can be involved in various pathological processes if expression levels are abnormal. It is a challenge to develop effective fluorescence-based tools to selectively distinguish Cys from Hcy and GSH because of their common functional groups. For most existing Cys fluorescent probes, their application is greatly restricted by the influence of aggregation-caused quenching (ACQ). In this work, a novel fluorescent probe, PE-YW, for Cys was designed rationally via regulating its AIE-based effects. The probe PE-YW took advantage of a specific conjugate addition cyclization reaction between Cys and an acrylate moiety, inducing the aggregation of PE-OH and showing large turn-on fluorescence (about 7-fold). The probe could detect Cys over other amino acids with high selectivity and a low detection limit (LOD = 1.72 nM). In addition, PE-YW exhibited excellent performance, such as a high fluorescence quantum yield (δ = 0.8) and a fast response toward Cys (

In recent years, the antitumor application of photodynamic therapy (PDT) has gained widespread interest in treating solid tumors. Due to the hypoxic environment in tumors, the major limit of PDT seems to be the source of oxygen. In this work, we attempted to relieve hypoxia and enhance photodynamic therapy, and therefore, designed and assembled a catalytic cascade-enhanced PDT multifunctional nanoplatform. The mentioned platform termed UIO@Ca-Pt is based on porphyrinic metal-organic framework (UIO) combination, which is simultaneously loaded by CaO2 NPs with polydopamine (PDA) and then the Pt raw material to further improve biocompatibility and efficiency. In a tumor microenvironment, CaO2 could react with water to generate calcium hydroxide and hydrogen peroxide, which was further decomposed by Pt nanoparticles to form oxygen, thereby facilitating the generation of cytotoxic singlet oxygen by photosensitizer TCPP under laser irradiation. Both in vitro and in vivo experiment results confirmed the excellent oxygen production capacity and enhanced PDT effect of UIO@Ca-Pt. With guaranteed safety in PDT, the oxygen-supplying strategy might stimulate considerable interest in the development of various metal-organic materials with multifunctionality for tumor diagnosis and therapy.

Synthesis of septal peptidoglycan (sPG) is crucial for bacterial cell division. FtsW, an indispensable component of the cell division machinery in all walled bacterial species, was recently identified in vitro as a peptidoglycan glycosyltransferase (PGTase). Despite its importance, the septal PGTase activity of FtsW has not been demonstrated in vivo. How its activity is spatiotemporally regulated in vivo has also remained elusive. Here, we confirmed FtsW as an essential septum-specific PGTase in vivo using an N-acetylmuramic acid analogue incorporation assay. Next, using single-molecule tracking coupled with genetic manipulations, we identified two populations of processively moving FtsW molecules: a fast-moving population correlated with the treadmilling dynamics of the essential cytoskeletal FtsZ protein and a slow-moving population dependent on active sPG synthesis. We further identified that FtsN, a potential sPG synthesis activator, plays an important role in promoting the slow-moving population. Our results suggest a two-track model, in which inactive sPG synthases follow the ‘Z-track’ to be distributed along the septum and FtsN promotes their release from the Z-track to become active in sPG synthesis on the slow ‘sPG-track’. This model provides a mechanistic framework for the spatiotemporal coordination of sPG synthesis in bacterial cell division. Single-molecule tracking of the septal peptidoglycan glycosyltransferase FtsW reveals two populations: a fast-moving one that follows treadmilling FtsZ and a slow-moving one that is involved in peptidoglycan synthesis.

C30H48O5, orthorhombic, P212121 (no. 19), a = 11.6608(10) Å, b = 14.8098(15) Å, c = 15.9975(16) Å, V = 2762.7(5) Å3, Z = 4, Rgt (F) = 0.0586, wRref (F 2) = 0.1580, T = 293(2) K.

Employing a sequentially activated probe design method, an activatable, switchable and dual-mode probe was designed. This nanoprobe, HSDPP, could be effectively activated by H2 S to form H-type aggregates with green emission; subsequently, the aggregates could bind to mtDNA to form monomers and the emIssion color switched from green to deep-red. We exploited HSDPP to image exogenous and endogenous H2 S in living cells. Of note, for the first time, this novel nanoprobe with an optimal partition coefficient value (LogP=1.269) was successfully applied for tracking the endogenous H2 S upregulation stimulated by cystathionase activator S-adenosyl-L-methionine (SAM) in mice brains. Finally, our work provides an invaluable chemical tool for probing endogenous H2 S upregulation in vitro/vivo and, importantly, affords a prospective design strategy for developing switchable chemosensors to unveil the relationship between biomolecules and DNA in mitochondria in many promising areas.

Background: Identification of novel Ure inhibitors with high potency has received considerable attention. Methodology & results: Ure inhibition was determined using the indophenol method, the affinities to Ure were estimated via surface plasmon resonance. Seventeen new plus ten known N-monosubstituted thiosemicarbazides were synthesized and identified as novel Ure inhibitors. Out of these compounds, compound b5 shows excellent activity against both crude Ure from Helicobacter pylori (IC50 = 0.04 μM) and Ure in living cell (IC50 = 0.27 μM), with the potency being over 600-fold higher than clinical used drug acetohyroxamic acid, respectively. Surface plasmon resonance demonstrated the high affinity ( Kd.#x00A0;= 6.32 nM) of b5 to Ure. Conclusion: This work provides a class of novel and promising Ure inhibitors.

Cysteine/cystine redox couple plays a vital role in maintaining the cellular redox state of living bio-systems. However, the dynamic changes of the intracellular cysteine/cystine pool mediated by cysteine/glutamate transporter (System XC−) in various cellular processes have remained incompletely understood. Here we established a series of strategies around fluorescent probe CP2 for effectively monitoring the intracellular cysteine level in living cells and in vivo zebrafish model, therefore for tracking dynamic changes of system XC−-mediated cysteine/cystine pool under ferroptosis. Living cell imaging and in vivo visualization both revealed that intracellular cysteine levels could be significantly reduced upon blocking system XC− activity and inducing ferroptotic cell death. This kind of blocking was potent against cisplatin-resistant A549R cancer cells, which might bring new potential for treating drug-resistant carcinoma through regulating system XC− and processes of ferroptosis. With further improvements in monitoring tools, understanding of system XC−-mediated cystine/cysteine pool and ferroptosis could certainly offer crucial information in more physiological or pathological processes.

Mercury is a highly toxic and non-essential element that is found in every corner of the globe. The small amount of mercury produced by various pathways eventually enters freshwater and marine ecosystems, circulating through the food chain (especially fish) and causing various environmental problems in aspects including plants, animals, and human. There are several traditional quantitative methods developed for mercury ions (II) analysis in water samples. However, due to the complexity of the detection process, high cost and strong technical expertise, it is difficult to detect mercury ions in real-time. Therefore, in recent years, a large number of researchers have developed small-molecule fluorescent probes for Hg ions detection. Fluorimetry has the advantages of convenient detection, short response time, high sensitivity and good selectivity. This review summarized the small-molecule fluorescent probes for mercuric ion detection developed in recent years according to the chemical structural classification, compared their performances and elaborated the mechanism. We hope that the review will help the researches for the designs of metal ions fluorescent probes and their applications with certain reference value.

The iridium-catalyzed enantioselective coupling reaction of vinyl azides and allylic electrophiles is presented and provides access to β-chiral carbonyl derivatives. Vinyl azides are used as acetamide enolate or acetonitrile carbanion surrogates, leading to γ,δ-unsaturated β-substituted amides as well as nitriles with excellent enantiomeric excess. These products are readily transformed into chiral N-containing building blocks and pharmaceuticals. A mechanism is proposed to rationalize the chemoselectivity of this coupling reaction.

The limited amount of electron mediators (EMs) excreted by microorganisms has restricted electricity generation and the related pollutant removal in microbial fuel cells (MFCs). The polyphenolic-rich plants contain simple polyphenols or anthraquinones that have promising electron-shuttling potential, but this has not been well understood. Herein, four herbal plants Polygonum multiflorum (T. fallopia), rhubarb (B. rheum), radix rubiae (L. Rubia) and semen cassiae (Catsia tora Linn) were selected and then studied to produce EMs to stimulate electricity generation in MFCs. B. rheum had the highest redox activity and 2% acid pretreatment contributing the most to the release of electroactive substances. The highest power density (18.67 W/m3) and Coulombic efficiency (29.03%) and the lowest internal resistance (29.02 Ω) were achieved in MFCs with B. rheum addition compared to other herbal plants. The satisfactory COD (93.68%) and NH4+-N (39.68%) removal were also obtained with a 0.01 g/L dosage. Confocal laser scanning microscopy and high throughput sequencing analysis showed that B. rheum had the least negative effects on biofilm microstructure and microbial species, corresponding to its outstanding performance. These findings first suggested that B. rheum can be regarded as a promising redox mediator to improve MFC performance. This study provided a new thinking to apply herbal wastewater or pharmaceutical waste in improving the bioelectrochemical system.

Taking advantage of V-shaped ligands, a ZnII metallocryptand, namely {[Zn2(didp)2(m-bdc)2]} n , (1) [didp = 2,8-di(1H-imidazol-1-yl)-dibenzothiophene and m-H2bdc = isophthalic acid], has been hydrothermally synthesized. Single-crystal X-ray diffraction analysis reveals a 26-membered butterfly-type metallomacrocycle [Zn2(didp)2]. One m-bdc2− ligand bridges [Zn2(didp)2] units to form a laterally non-symmetric [Zn2(didp)2(m-bdc)] metallocryptand with an exo–exo conformation. Another crystallographically independent m-bdc2− functions as a secondary synthon to bridge discrete metallocryptands into a 1D zigzag chain architecture. Undoubtedly, the choice of two matched ligands in this work is crucial for metallocryptand construction and structure expansion. Interestingly, a rare helical chain with two flexures in one single L and/or R strand is observed. Another important feature is the C—O...π interactions, by which the dimensionality extension of (1) can be induced. Fluorescence measurements and density functional theory (DFT) calculations illustrate that the emission of (1) can probably be attributed to ligand-to-ligand charge transfer (LLCT).

Synthesis and self-assembly of stimuli-responsive amphiphilic alternating copolymers (AAC) are an emerging land of tremendous possibilities. Herein, by combining backbone polyethylene glycol (PEG) with pendent oligo-polyglycol simultaneously, two alternating LCST segments are knitted through enzymatic synthesis, giving a series of alternating poly[(PEG400-a-succinic acid)-co-(diol(3EG)-a-succinic acid)] (PPSDS) for the first time. All the PPSDSs show only one-step sharp temperature responsiveness in transmittance–temperature curve owing to stabilization effect of PEG400. The cloud points can be linearly controlled by simply adjusting the feeding ratio of PEG400/diol-3EG. Referring to published works and 1H-NMR spectra in D2O, all the obtained AAC formed penetrable nanovesicles under 4 °C. The TEM and 1H-NMR results confirmed that when heated to 18 °C, PPSDS of “9/1” transformed from nanovesicles to large-compound micelles due to large hydrophobic volume, while other PPSDS of “8/2, 7/3, 6/4” retained the vesicle structures, except that the hydrophilic layer turned from PEG400 + diol(3EG) to PEG400 alone, leading to the size reduction. The temperature-controlled size “expansion and contraction” of nanovesicles was unique for AAC, which was potentially good for enhancing loading rate. Further heating above cloud point resulted in the destruction of nanostructures and irregular intermolecular aggregations. The first reported dual temperature-responsive AAC was innovative in structure design, providing a potential opportunity for the design and synthesis of controllable self-assemble structures and smart biomacromolecules in biomedical applications.

Nickel-based composite coatings reinforced by spherical tungsten carbide were deposited on 42CrMo alloy steel using plasma transfer arc welding (PTAW) process. Their electrochemical corrosion properties in NaCl solution under atmospheric and high pressure were studied by polarization curve, electrochemical impedance spectroscopy. The corrosion and erosion resistance of the coatings were also investigated by salt spray corrosion and erosion corrosion tests. The results show that the self-corrosion potential of the composite coatings increased with the increase of tungsten carbide content, and the Cr element in Ni60 sample formed a stable and compact passivation film. Compared with corrosion at atmospheric pressure, the adsorption and penetration of Cl- on the coating surface enhanced due to the increase of Cl- activity under pressure, thereby to weaken the corrosion resistance. The Samples that passivated in salt spray environment, cannot completely hinder the corrosion of the coating, just only to slow down the corrosion. This study can provide theoretical basis for deep-sea oil drilling and production engineering equipment.

Background The mitogen-activated protein kinases (MAPKs), as a part of the MAPKKK-MAPKK-MAPK cascade, play crucial roles in plant development as an intracellular signal transduction pathway to respond various environmental signals. However, few MAPKK have been functionally characterized in grapevine. Results In the study, five MAPKK (MKK) members were identified in grapevine (cultivar ‘Pinot Noir’), cloned and designated as VvMKK1-VvMKK5. A phylogenetic analysis grouped them into four sub-families based on the similarity of their conserved motifs and gene structure to Arabidopsis MAPKK members. qRT-PCR results indicated that the expression of VvMKK1, VvMKK2, VvMKK4, and VvMKK5 were up-regulated in mature leaf and young blades, and roots, but exhibited low expression in leaf petioles. VvMKK2, VvMKK3, and VvMKK5 genes were differentially up-regulated when grapevine leaves were inoculated with spores of Erisyphe necator, or treated with salicylic acid (SA), ethylene (ETH), H2O2, or exposed to drought, indicating that these genes may be involved in a variety of signaling pathways. Over expression of VvMKK2 and VvMKK4 genes in transgenic Arabidopsis plants resulted in the production of seeds with a significantly higher germination and survival rate, and better seedling growth under stress conditions than wild-type plants. Overexpression of VvMKK2 in Arabidopsis improved salt and drought stress tolerance while overexpression of VvMKK4 only improved salt stress tolerance. Conclusions Results of the present investigation provide a better understanding of the interaction and function of MAPKKK-MAPKK-MAPK genes at the transcriptional level in grapevine and led to the identification of candidate genes for drought and salt stress in grapes.

Antisense oligonucleotides (ASOs) interact with target RNAs via hybridization to modulate gene expression through different mechanisms. ASO therapeutics are chemically modified and include phosphorothioate (PS) backbone modifications and different ribose and base modifications to improve pharmacological properties. Modified PS ASOs display better binding affinity to the target RNAs and increased binding to proteins. Moreover, PS ASO protein interactions can affect many aspects of their performance, including distribution and tissue delivery, cellular uptake, intracellular trafficking, potency and toxicity. In this review, we summarize recent progress in understanding PS ASO protein interactions, highlighting the proteins with which PS ASOs interact, the influence of PS ASO protein interactions on ASO performance, and the structure activity relationships of PS ASO modification and protein interactions. A detailed understanding of these interactions can aid in the design of safer and more potent ASO drugs, as illustrated by recent findings that altering ASO chemical modifications dramatically improves therapeutic index.

A copper-catalyzed three-component reaction of terminal alkynes, TsN3, and tertiary allylic amines is developed toward the one-pot synthesis of α-allylic amidines. The product was synthesized on gram scale under 1 mol % of catalyst loading. Transformations of products into alkenyl amine and other nitrogen-containing compounds are demonstrated without any loss of stereochemical information.

Purpose Currently, thalassemia is commonly detected using gap-polymerase chain reaction (PCR) and deoxyribonucleic acid (DNA) reverse dot blot, which have high requirements of space, instruments, and personnel. Therefore, it is necessary to develop a new method for thalassemia detection with high sensitivity, low cost, and simple and fast operation. In this study, we aimed to design and evaluate a new method for detecting three α-thalassemia genes including -Southeast Asian (SEA), -α3.7, and -α4.2 and five β-thalassemia genes including 654M, 41/42M, -28M, 17M, and 27/28M based on loop-mediated isothermal amplification (LAMP). Methods Primer sequences were designed using Primer Explorer V4 software. Blood samples (5 mL) were collected from all participants in EDTA. DNA was extracted using Chelex 100 and was subjected to LAMP. LAMP products were detected by fluorescence development in ultraviolet light. Results We found that LAMP assays for positive samples of thalassemia reached a plateau before 60 minutes, whereas the negative control samples entered the plateau after 70 minutes or showed no amplification. The concentration range of positive reactions was between 20-60 pg/μL and 20-60 ng/μL. Additionally, there were no cross-reactivities among 8 thalassemia subtypes. For clinical samples, the positive sample tube showed strong green fluorescence, whereas the negative tube showed light green fluorescence. According to these results, the LAMP method has high sensitivity for detecting thalassemia (252/254). However, 43 false-positive results were obtained in the LAMP test. The LAMP assay was also of low cost and with simple and fast operation. Conclusion The novel LAMP assay can be completed within 60 min using a heating block or a water bath, and the result can be read visually based on color change to detect thalassemia. The LAMP assay fulfills the requirements of field application and resource-limited areas, especially those with primary hospitals and rural areas.

Therapeutic oligonucleotides are often modified using the phosphorothioate (PS) backbone modification which enhances stability from nuclease mediated degradation. However, substituting oxygen in the phosphodiester backbone with sulfur introduce chirality into the backbone such that a full PS 16-mer oligonucleotide is comprised of 215 distinct stereoisomers. As a result, the role of PS chirality on the performance of antisense oligonucleotides (ASOs) has been a subject of debate for over two decades. We carried out a systematic analysis to determine if controlling PS chirality in the DNA gap region can enhance the potency and safety of gapmer ASOs modified with high-affinity constrained Ethyl (cEt) nucleotides in the flanks. As part of this effort, we examined the effect of systematically controlling PS chirality on RNase H1 cleavage patterns, protein mislocalization phenotypes, activity and toxicity in cells and in mice. We found that while controlling PS chirality can dramatically modulate interactions with RNase H1 as evidenced by changes in RNA cleavage patterns, these were insufficient to improve the overall therapeutic profile. We also found that controlling PS chirality of only two PS linkages in the DNA gap was sufficient to modulate RNase H1 cleavage patterns and combining these designs with simple modifications such as 2′-OMe to the DNA gap resulted in dramatic improvements in therapeutic index. However, we were unable to demonstrate improved potency relative to the stereorandom parent ASO or improved safety over the 2′-OMe gap-modified stereorandom parent ASO. Overall, our work shows that while controlling PS chirality can modulate RNase H1 cleavage patterns, ASO sequence and design are the primary drivers which determine the pharmacological and toxicological properties of gapmer ASOs.

The tumorigenic role and underlying mechanisms of lipid accumulation, commonly observed in many cancers, remain insufficiently understood. In this study, we identified an AMP-activated protein kinase (AMPK)–GATA-binding protein 3 (GATA3)–enoyl-CoA hydratase short-chain 1 (ECHS1) pathway that induces lipid accumulation and promotes cell proliferation in clear cell renal cell carcinoma (ccRCC). Decreased expression of ECHS1, which is responsible for inactivation of fatty acid (FA) oxidation and activation of de novo FA synthesis, positively associated with ccRCC progression and predicted poor patient survival. Mechanistically, ECHS1 downregulation induced FA and branched-chain amino acid (BCAA) accumulation, which inhibited AMPK-promoted expression of GATA3, a transcriptional activator of ECHS1. BCAA accumulation induced activation of mTORC1 and de novo FA synthesis, and promoted cell proliferation. Furthermore, GATA3 expression phenocopied ECHS1 in predicting ccRCC progression and patient survival. The AMPK–GATA3–ECHS1 pathway may offer new therapeutic approaches and prognostic assessment for ccRCC in the clinic. Significance: These findings uncover molecular mechanisms underlying lipid accumulation in ccRCC, suggesting the AMPK–GATA3–ECHS1 pathway as a potential therapeutic target and prognostic biomarker.

Luminescent metal-organic frameworks (LMOFs), as one branch of MOFs, have attracted considerable attention in recent years due to their good crystallinity, structural diversity, tunable porosity and easily induced fluorescence emission. Importantly, their photoluminescence (PL) properties can be adjusted by altering metal ions or metal clusters and organic ligands in one hybrid system. Among the various sensing applications, using LMOFs as chemical sensors to detect the explosive and environment pollution causing nitroaromatic compounds (NACs) is an important topic. In this account, we describe the recent advancements in the field of NAC detection by LMOFs based on the triphenylamine (TPA) unit as the π-conjugated fluorophore.

The purpose of this study was to evaluate the effects of diosgenin on the D-galactose-induced cerebral cortical widely dispersed apoptosis. Male 12-week-old Wistar rats were divided into four groups: Control (1[Formula: see text]mg/kg/day of saline, i.p.), DD0 (150[Formula: see text]mg/kg/day of D-galactose, i.p.), DD10, and DD50 (D-galactose[Formula: see text] or 50[Formula: see text]mg/kg/day of diosgenin orally). After eight weeks, histopathological analysis, positive TUNEL and Western blotting assays were performed on the excised cerebral cortex from all four groups. The TUNEL-positive apoptotic cells, the components of Fas pathway (Fas, FADD, active caspase-8 and active caspase-3), and mitochondria pathway (t-Bid, Bax, cytochrome [Formula: see text], active caspase-9 and active caspase-3) were increased in the DD0 group compared with the control group, whereas they were decreased in the DD50 group. The components of survival pathway (p-Bad, Bcl-2, Bcl-xL, IGF-1, p-PI3K and p-AKT) were increased in the DD50 group compared to the control group, whereas the levels of Bcl-xL, p-PI3K, and p-AKT were also compensatorily increased in the DD0 group compared to the control group. Taken together, diosgenin suppressed D-galactose-induced neuronal Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced the Bcl-2 family associated pro-survival and IGF-1-PI3K-AKT survival pathways, which might provide neuroprotective effects of diosgenin for prevention of the D-galactose-induced aging brain.

Aldosterone, which plays a key role in the regulation of blood pressure, is produced by zona glomerulosa (ZG) cells of the adrenal cortex. Exaggerated overproduction of aldosterone from ZG cells causes primary hyperaldosteronism. In ZG cells, calcium entry through voltage-gated calcium channels plays a central role in the regulation of aldosterone secretion. Previous studies in animal adrenals and human adrenal adrenocortical cell lines suggest that the T-type but not the L-type calcium channel activity drives aldosterone production. However, recent clinical studies show that somatic mutations in L-type calcium channels are the second most prevalent cause of aldosterone-producing adenoma. Our objective was to define the roles of T and L-type calcium channels in regulating aldosterone secretion from human adrenals. We find that human adrenal ZG cells mainly express T-type CaV3.2/3.3 and L-type CaV1.2/1.3 calcium channels. TTA-P2, a specific inhibitor of T-type calcium channel subtypes, reduced basal aldosterone secretion from acutely prepared slices of human adrenals. Surprisingly, nifedipine, the prototypic inhibitor of L-type calcium channels, also decreased basal aldosterone secretion, suggesting that L-type calcium channels are active under basal conditions. In addition, TTA-P2 or nifedipine also inhibited aldosterone secretion stimulated by angiotensin II- or elevations in extracellular K+. Remarkably, blockade of either L- or T-type calcium channels inhibits basal and stimulated aldosterone production to a similar extent. Low concentrations of TTA-P2 and nifedipine showed additive inhibitory effect on aldosterone secretion. We conclude that T- and L-type calcium channels play equally important roles in controlling aldosterone production from human adrenals.

A novel cascade reaction of 1-(o-aminophenyl)prop-2-ynols with the P(O)–H species has been developed, which leads to C2-phosphorylmethylindoles with sequential C–P and C–N bond formation in a single operation. Mechanistic studies suggest that the reaction proceeds via a carbocation initiated tandem phosphorylation/5-exo-dig cyclization, which firstly demonstrates the tandem allene formation/cyclization as a new reaction mode of 1-(o-aminophenyl)prop-2-ynols.

Isoliquiritigenin (2’,4’,4-trihydroxychalcone, ISL) is one of the most important chalcone compounds which is mainly derived from licorice root and many other plants. It exhibits a remarkable range of potent biological and pharmacological activities such as antioxidative, antitumor, antiaging, anti-inflammatory, anti-diabetic activities, etc. Numerous research teams have demonstrated that ISL posseses the ability to carry out antigrowth and proliferation in various cancer cells in vitro and in vivo. Meanwhile, the underlying mechanisms of ISL that inhibit cancer cell proliferation have not been well explored. However, the poor bioavailability and low water-soluble limit its clinical application. This review aims at providing a comprehensive overview of the pharmacology antitumor activity of ISL and its mechanisms in different malignancy especially in breast cancer cell line and summarize developments of formulation utilized to overcome the barrier between its delivery characteristics and application in clinics over the past 20 years.

Aim Our previous transcriptome sequencing analysis detected that retinol dehydrogenase 16 (RDH16) was dramatically downregulated in hepatocellular carcinoma (HCC). RDH16 belongs to the short-chain dehydrogenases/reductases super family, and its role in HCC remains unknown. This study aimed to investigate the expression and function of RDH16 in HCC. Methods The mRNA and protein level of RDH16 in HCC samples were detected by quantitative real-time polymerase chain reaction and immunohistochemistry analyses, respectively. The role of RDH16 in HCC was determined by in vitro and in vivo functional studies. Results Downregulation of RDH16 has been detected in approximately 90% of primary HCCs, which was significantly associated with high serum alpha-fetoprotein level, tumor size, microsatellite formation, thrombus, and poor overall survival of HCC patients. Compared with non-tumor tissues, higher density of methylation was identified in HCC samples. In addition, RDH16 increases the level of retinoic acid and blocks the de novo synthesis of fatty acid in HCC cells. Functional study shows that ectopic expression of RDH16 in HCC cells suppresses cell growth, clonogenicity, and cell motility. Conclusions RDH16 might be a prognostic biomarker and intervention point for new therapeutic strategies in HCC.

Sulfur dioxide (SO2) had been recognized as an environmental pollutant produced from industrial processes. SO2 is water soluble and forms hydrated SO2 (SO2·H2O), bisulfite ion (HSO3−), and sulfite ion (SO32−) upon dissolution in water. SO2 could be also produced endogenously from sulfur-containing amino acids l -cysteine in mammals. Endogenous SO2 can maintain the balance of biological sulfur and redox equilibrium in vivo, regulate blood insulin levels and reduce blood pressure. Excess intake of exogenous SO2 can result in respiratory diseases, cardiovascular diseases and neurological disorders. As a result, fluorescent probes to detect HSO3−/SO32− have attracted great attention in recent years. Herein, a general overview was provided with the aim to highlight the typical examples of the HSO3−/SO32− fluorescent probes reported since 2010, especially those in the past five years. We have classified HSO3−/SO32− fluorescent probes through different chemical reaction mechanisms and wish this review will give some help to the researchers in this field.

A novel 1,8-naphthalimide-based OFF-ON type fluorogenic sydnone (Naph-Syd) is designed as bioorthogonal probe for imaging. Sydnone moiety efficiently quenches the native fluorescence of 1,8-naphthalimide, which can be restored with the enhancement of about 300-fold, after reacting with strained cyclooctynes to form pyrazole products (Naph-Pyr). The second-order rate constant of this bioorthogonal cycloaddition can be up to 2.5 L mol−1 s−1, which benefits imaging of biomolecules at low concentrations in cellular environment.

Thirty-eight disulfides containing N-arylacetamide were designed and synthesized in an effort to develop novel urease inhibitors. Biological evaluation revealed that some of the synthetic compounds exhibited strong inhibitory potency against both cell-free urease and urease in intact cell with low cytotoxicity to mammalian cells even at concentration up to 250 µM. Of note, 2,2'-dithiobis(N-(2-fluorophenyl)acetamide) (d7), 2,2'-dithiobis(N-(3,5-difluorophenyl)acetamide) (d24), and 2,2'-dithiobis(N-(3-fluorophenyl)acetamide) (d8) were here identified as the most active inhibitors with IC50 of 0.074, 0.44, and 0.81 µM, showing 32- to 355-fold higher potency than the positive control acetohydroxamic acid. These disulfides were confirmed to bind urease without covalent modification of the cysteine residue and to inhibit urease reversibly with a mixed inhibition mechanism. They also showed very good anti-Helicobacter pylori activities with d8 showing a comparable potency to the clinical used drug amoxicillin. The impressive in vitro biological profile indicated their immense potential as therapeutic agents to tackle H. pylori caused infections.

Achieving selective release of chemical anticancer agents and improving therapeutic efficacy has always been a hot spot in the field of cancer research, yet how to achieve this remains a great challenge. In this work, we constructed a novel chemical anticancer agent (named MCLOP) by introducing naphthalimide into the skeleton of methylene blue (MB). Under the stimulation by cellular hypochlorous acid (HClO) and visible light, selective release of active naphthalimide can be achieved within breast cancer cell lines, the release process of which can be tracked visually using near-infrared fluorescence of MB (685 nm). More importantly, we developed biotinylated curcumin (Cur-Bio) as a new chemosensitizer, which significantly enhanced the ability of MCLOP to induce autophagic cell death of breast cancer cells. This synergistic treatment strategy exhibited an excellent anti-proliferation effect on breast cancer cells in vitro, three-dimensional (3D) cell sphere model, and mouse tumor model in vivo. This work provides a new strategy for the treatment of breast cancer and also opens new opportunities for the efficient treatment of cancer with curcumin-based chemosensitizer.

C24H21F6NO3, monoclinic, P21/c (no. 14), a = 16.6493(9) Å, b = 15.3005(8) Å, c = 8.8554(5) Å, β = 99.746(6)°, V = 2223.3(2) Å3, Z = 4, R gt (F) = 0.0444, wR ref (F 2) = 0.1094, T = 100 K.

A new copper-thiolate cluster assembled framework [Cu2(µ4-SCH3)Cl]n (1), has been solvothermally synthesized through in situ reaction viz., in situ ligand generation and metal reduction. Compound 1 represents the first 3D framework based on Atlas-sphere functionalized by single µ2-Cl− groups. DOS calculation reveals the interaction of electronic structures. It is found that the HOMO is mainly distributed on Cl, Cu and S bonding orbitals, while the LUMO is dominated by Cu-Cl antibonding orbitals.

The present paper aimed to investigate the roles of quinones contained in wastewater and the enhanced effects on microbial fuel cells (MFCs) under different redox conditions. The feasibility of using wastewater rich in quinones to act as co-substrate and redox mediators (RMs) library to strengthen the synergistic removal of azo dye in MFCs was evaluated. The results demonstrated that quinones achieved enhanced effects on electricity generation and COD removal of MFC better at higher current intensity. The addition of pure quinone decreased electron transfer resistance (Rct) of MFCs from 4.76 Ω to 2.13 Ω under 1000 Ω resistance and 1.16 Ω–0.75 Ω under 50 Ω resistance. Meanwhile, higher coulombic efficiency was achieved. Compared with sodium acetate, using quinone-rich traditional Chinese medicine (TCM) wastewater as the co-substrate enhanced the synergistic removal of reactive red 2 (RR2) in MFCs from 79.58% to 92.45% during 24 h. RR2 was also degraded more thoroughly due to the accelerated electron transfer process mediated by RMs. Microbial community analysis demonstrated that the presence of quinone in TCM wastewater can enrich different exoelectrogens under varied redox conditions and thus influenced the enhanced effects on MFC. Metagenomic functional prediction results further indicated that the abundance of functional genes involved in carbohydrate metabolism, membrane transport metabolism, biofilm formation, and stress tolerance increased significantly in presence of RMs. Redundancy analyses revealed that RMs addition was the more important factor driving the variation of the microorganism community. This study revealed the potential effect of quinones as redox mediators on the bioelectrochemical system for pollutants removal.

Realizing the early diagnosis of acute liver injury has become a hotspot in recent years. Since the current indexes are not specific, developing novel probes with new recognition group remains a necessity. In this work, we developed a novel fluorescent probe, NNP, for the detection of ONOO− in acute liver injury (ALI). The in vitro evaluation of NNP indicated the advantages including high sensitivity (LOD = 0.13 μM), rapid response (48 h) conditions. Accordingly, NNP achieved the dose-dependent detection of ONOO− in human hepatic stellate LX-2 cells. Further, in the ALI model mice, NNP could monitor the ONOO− level in the occurrence of ALI in situ (in the liver region) with a steady performance. Subsequent immunohistochemical and imaging studies confirmed that NNP could achieve the detection of endogenous ONOO− in ALI liver tissues. This work introduced a practical implement for the ONOO− detection in ALI as well as a referable example for the establishment of molecular indexes in pre-clinical diagnosis., Highlights • A novel fluorescent probe, NNP, for the detection of ONOO− in acute liver injury model. • High sensitivity, high selectivity, rapid response and steadiness for over 48 h. • Applications in human hepatic stellate cell line for cellular imaging of ONOO− level. • Achieving the detection of endogenous ONOO− in mice and liver tissues.

Lithocarpus polystachyus Rehd. known as Sweet Tea in China has attracted lots of interest for its good hypoglycemic effect and the potential as a hypoglycemic agent. Based on affinity separation-UPLC-Q-TOF-MS/MS, 54 potential α-glucosidase inhibitiors were identified and 44 were structurally determined. Out of them, 41 were identified for the first time from this plant including flavonoids, fatty acids, triterpenes, alkaloids, and coumarins. Enzyme assays revealed that flavonoids exhibited higher inhibitory activity against α-glucosidase than others with astilbin (IC50 = 6.14 μg·mL−1), morin (IC50 = 8.46 μg·mL−1), and naringenin (IC50 = 10.03 μg·mL−1) showing 2- to 4-fold higher potency than the positive control acarbose. They were proved as reversible inhibitors with mixed inhibition mechanism. K i ( K i ' ) values and molecular dockings strongly supported the potency order of astilbin, morin and naringenin that showed in the enzyme assays.

Antisense oligonucleotides modified with phosphorothioate linkages (PS-ASOs) can enter cells via endocytic pathways and must escape from membraned organelles to reach target RNAs. We recently found that membrane destabilization induced by different lipid species contributes to PS-ASO release from late endosomes (LEs). In this study, we characterized intracellular uptake, trafficking, and activities of PS-ASOs conjugated with different lipid species. We found that palmitic acid-, tocopherol-, and cholesterol-conjugated PS-ASOs have increased protein binding and enhanced intracellular uptake compared to unconjugated PS-ASOs. Similar to the parental PS-ASO, the lipid-conjugated PS-ASOs traffic from early to LEs without incorporation into lipid droplets. Unlike parental PS-ASOs, the lipid-conjugated PS-ASOs tend to remain associated with plasma or endosomal membranes, and this appears to influence their release from endosomes. The lipid-conjugated PS-ASOs were released more rapidly than parental PS-ASO. These results suggest that lipid conjugation enhances the interactions of PS-ASOs with proteins or membranes, in turn facilitating intracellular trafficking and endosomal release.

Introduction of (S)-configuration is the key step in the synthesis of the anti-dementia drug Rivastigmine. Twenty-one alkylation products were obtained through simple washing with hexane/ethyl acet...

Mutated adenomatous polyposis coli (APC) selectively combining with Asef has been reported to be implicated in promoting colon cancer proliferation, invasion and metastasis in several cancer biotherapy studies. However, there were universally resistance and harsh terms in disrupting APC-Asef interaction in biotherapy. Under the circumstances small-molecule inhibitors as the new APC interface could resolve the problems. In this research, a series of novel dihydropyrazole derivatives containing morpholine as high potent interaction inhibitors between APC and Asef were first synthesized after selection by means of docking simulation and virtual screening. Afterwards they were evaluated interaction inhibition of APC-Asef and pharmacological efficiency both in vitro and in vivo utilizing orthotopic transplantation model with multi-angle of view. Among them, compound 7g exhibited most excellent anti-proliferation activities against HCT116 cells with IC50 of 0.10 ± 0.01 μM than Regorafenib (IC50 = 0.16 ± 0.04 μM). The results favored our rational design intention and provides a new class of small-molecule inhibitors available for the development of colon tumor therapeutics targeting APC-Asef interaction inhibitions.

Hydrogen peroxide (H2O2), as one kind of the most significant reactive oxygen species (ROS), is associated with many physiological and pathological processes in biological systems. Therefore, in order to understand the vital roles of H2O2 in living systems, many small-molecule fluorescent probes for its detection in biological field have been reported in recent years. To highlight the recent advances in fluorescence imaging of H2O2, in this review, small-molecule fluorescent probes that detect H2O2 over the recent years (2003–2018) were summarized and organized based on their different response mechanisms. We divided the probes into nine categories. The design strategies of different combinations between fluorophores, recognition groups, and detection mechanisms were all discussed. Finally, we briefly scoped the challenges and future directions in this field. We believe that the essential role of H2O2 in living systems will be understood along with more novel probes or mechanisms coming to light.