The Diversity of a Polyclonal FluCell-SELEX Library Outperforms Individual Aptamers as Emerging Diagnostic Tools for the Identification of Carbapenem Resistant Pseudomonas aeruginosa

Textbook procedures require the use of individual aptamers enriched in SELEX libraries which are subsequently chemically synthesized after their biochemical characterization. Here we show that this reduction of the available sequence space of large libraries and thus the diversity of binding molecules reduces the labelling efficiency and fidelity of selected single aptamers towards different strains of the human pathogen Pseudomonas aeruginosa compared to a polyclonal aptamer library enriched by a whole-cell-SELEX involving fluorescent aptamers. The library outperformed single aptamers in reliable and specific targeting of different clinically relevant strains, allowed to inhibit virulence associated cellular functions and identification of bound cell surface targets by aptamer based affinity purification and mass spectrometry. The stunning ease of this FluCell-SELEX and the convincing performance of the P. aeruginosa specific library may pave the way towards generally new and efficient diagnostic techniques based on polyclonal aptamer libraries not only in clinical microbiology.     

Light-Activated Carbon Monoxide Prodrugs Based on Bipyridyl Dicarbonyl Ruthenium(II) Complexes

Two photoactivatable dicarbonyl ruthenium(II) complexes based on an amide-functionalised bipyridine scaffold (4-position) equipped with an alkyne functionality or a green-fluorescent BODIPY (boron-dipyrromethene) dye have been prepared and used to investigate their light-induced decarbonylation. UV/Vis, FTIR and ¹³C NMR spectroscopies as well as gas chromatography and multivariate curve resolution alternating least-squares analysis (MCR-ALS) were used to elucidate the mechanism of the decarbonylation process. Release of the first CO molecule occurs very quickly, while release of the second CO molecule proceeds more slowly. In vitro studies using two cell lines A431 (human squamous carcinoma) and HEK293 (human embryonic kidney cells) have been carried out in order to characterise the anti-proliferative and anti-apoptotic activities. The BODIPY-labelled compound allows for monitoring the cellular uptake, showing fast internalisation kinetics and accumulation at the endoplasmic reticulum and mitochondria.     

CdS@g-C3N4复合核壳纳米微粒的制备与光催化性能

采用水热法,在乙二胺和EDTA-2Na作用下,成功制备了CdS@g-C3N4复合核壳纳米微粒,并探讨了其生长机理。结果显示:CdS@g-C3N4复合核壳纳米微粒的比表面积是纯CdS纳米颗粒的14.0倍,具有良好的光催化活性和光稳定性。当反应条件为180℃、4 h、CdS/g-C3N4质量比1.9∶1时,CdS@g-C3N4的可见光催化性能最好,300 W氙灯光照2 h,RhB的降解率达95.2%,明显高于纯CdS。重复使用3次后,CdS@g-C3N4形貌、结构及光催化性能无明显变化。     

Structurally Interesting Diarymethane Derivatives from Securidaca inappendiculata

Securines A—E, three dimeric diarymethane derivatives ( 1 — 3 ) and two enantiomeric diarymethane derivative monomers ( 4 and 5 ), were isolated and characterized from the medicinal plant Securidaca inappendiculata. Compounds 1 and 2 are a pair of enantiomeric diarymethane derivative dimers, and compound 3 is a mesomeric diarymethane derivative dimer. Their structures were determined by a combination of spectroscopic data, X‐ray crystallography, electronic circular dichroism (ECD) analysis, and computational ECD calculations. Dimeric compounds 1 — 3 showed moderate antiplasmodial activities with IC₅₀ values of 0.9, 1.4, and 1.5 μM, respectively.     

Synthesis of Z-scheme g-C3N4 nanosheets/Ag3PO4 photocatalysts with enhanced visible-light photocatalytic performance for the degradation of tetracycline and dye

Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange(MO),rhodamine B(RhB)and tetracycline(TC)under visible light irradiation.The solutions containing RhB(10 mg/L)and MO(10 mg/L)can be efficiently degraded within15 min and 30 min.Especially,nearly 80%of TC(50 mg/L)is degraded within 20 min.which are much better than those of pure g-C3N4 nanosheets and Ag3PO4,implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries.Furthermore,the g-C3N4/Ag3PO4 composites exhibit the improved stability,and only a slight decrease is observed after three recycling runs.Moreover,the impact of inorganic ions and PH values on the degradation performance is rather small.The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed.This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues.     

Fabrication linalool-functionalized hollow mesoporous silica spheres nanoparticles for efficiently enhance bactericidal activity

To develop a novel food preservation technology for efficiently enhance bactericidal activity in a long term, hollow mesoporous silica spheres (HMSS) with regular nanostructures were applied to encapsulate natural organic antimicrobial agents. The chemical structures, morphologies and thermal stabilities of linalool, HMSS and linalool-functionalized hollow mesoporous silica spheres (L-HMSS) nanoparticles were evaluated by polarimeter, field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), fourier transform infrared (FT-IR), thermal gravimetric analyzer (TGA), nitrogen adsorption-desorption, zeta potential and small angle X-ray diffraction (SXRD). The results show that the linalool was successfully introduced into the cavities of HMSS, and the inorganic host exhibited a high loading capacity of about 1500 mg/g. In addition, after 48 h of incubation, the minimum bactericidal concentrations (MBC) of L-HMSS against Escherichia coli (E. coli), Salmonella enterica (S. enterica) and Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes) were decreased to be 4 (< 5) mg/mL and 8 (< 10) mg/mL, respectively. These results revealed linalool-functionalized hollow mesoporous spheres could efficiently improve the bactericidal activities of the organic component. Furthermore, SEM images clearly showed that L-HMSS indeed had an extremely inhibitory effect against gram-negative (E. coli) and gram-positive (S. aureus) by breaking the structure of the cell membrane. This research is of great significance in the application of linalool in nano-delivery system as well as food industry.     

Evaluation of pharmaceutical activities of G-protein coupled receptor targeted pharmaceuticals in Chinese wastewater effluent

The occurrence of biologically active pharmaceuticals in aquatic environments raised the potential risks to aquatic species. Among these marketed biological active pharmaceuticals, it has been estimated that 40% of them target G-protein-coupled receptors (GPCRs). We have illustrated pharmaceutical activities of GPCR targeted pharmaceuticals in English and Japanese wastewater by the in vitro transforming growth factor-α (TGFα) shedding assay. However, as the most important producer and consumer of pharmaceuticals, the occurrence of GPCR targeted pharmaceuticals in China had remained unclear. In this study, we investigated the pharmaceutical activities of GPCR targeted pharmaceuticals in secondary effluents of Chinese wastewater treatment plants. We discovered antagonistic activities against angiotensin (AT1) receptor at up to 7.2 × 102 ng-valsartan-equivalent quantity/L in Chinese wastewater for the first time as well as agonistic activities against dopamine (D2) receptor. Furthermore, in parallel with the assay, we determined concentrations of GPCR targeted pharmaceuticals in target wastewater by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). Through the comparison of predicted antagonistic activities calculated by concentrations and potency values from the assay, we found that the measured antagonistic activities against AT1 receptor from the assay were higher than the predicted AT1 activities from valsartan, irbesartan, and losartan, indicating the potential existence of other unknown AT1 antagonists in wastewater.     

Combining electronic properties and virtual screening for the development of new antioxidants: Trolox-like compounds as application example

Oxidative stress is an imbalance between the production of free radicals and the antioxidant defenses of the organism. Heart diseases, anemia, inflammation, and neurodegenerative disorders have been associated with this biological condition. Trolox is a notable antioxidant drug similar to vitamin E, and it is used to decrease the oxidative stress or repair the damage caused by it. In this work, the virtual screening technique is applied to identify compounds with antioxidant activities similar to Trolox. The antioxidant activity of these compounds was assessments by the mechanisms of hydrogen atom transfer and single electron transfer. Properties such as bond dissociation enthalpy, adiabatic ionization potential, Gibbs free reaction energy, spin density, highest occupied molecular orbital (HOMO), and GAP (HOMO-LUMO) energies, obtained from the DFT approach, point out to the predominance of the HAT mechanism for the antioxidant action of these compounds. The obtained results contribute to a better understanding of the chemical and physical properties responsible for antioxidant activity and the design of new antioxidant agents.     

新型α-蒎烯基苯磺酰胺类化合物的合成及其抗真菌活性

以天然产物α蒎烯为原料,经多步反应合成了9个新型α-蒎烯基苯磺酰胺类化合物（7a~7i）,其结构经¹H NMR、 ¹³C NMR、 FT-IR和MS(ESI)表征。采用离体法测试了化合物的抗真菌活性。结果表明：在50 μg·mL^-1浓度下,目标化合物对黄瓜枯萎病菌、花生褐斑病菌、苹果轮纹病菌、小麦赤霉病菌以及番茄早疫病菌等5种植物病原菌有一定的抑制活性,其中化合物α-蒎烯基p-氯苯基磺酰胺(7d, R=p-Cl)和α-蒎烯基o-硝基苯基磺酰胺(7h, R=o-NO₂)对苹果轮纹病菌的抑制率分别为83.9%和79.6%（B级活性水平）,优于阳性对照百菌清（75.0%）;化合物α-蒎烯基m-甲基苯基磺酰胺(7b, R=m-Me)对番茄早疫病菌的抑制率为82.2%（B级活性水平）,优于阳性对照百菌清（73.9%）。-     

N,O-Nucleoside Analogues: Metabolic and Apoptotic Activity

Two new families of N,O-nucleoside analogues containing the anthracene moiety introduced through the nitrosocarbonyl ene reaction with allylic alcohols were prepared. The core structure is an isoxazolidine heterocycle that introduces either atom either a phenyl ring or dimethyl moiety at the C3 carbon. Different heterobases were inserted at the position 5 of the heterocyclic ring. One of the synthesized compounds demonstrated a good capacity to induce cell death and an appreciable nuclear fragmentation was evidenced in treated cells.