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A novel multistage wastewater purification and conversion system (MWPCS) was designed to effectively remove and convert water-soluble dinitrotoluene (DNT). The MWPCS comprises a unique configuration, including the U-shaped solar evaporator (U-SE) with a white body, a polyelectrolyte multilayer (PEM)-coated roof dome, and a catalytic filter. The U-SE achieved a DNT removal efficiency (RE) of 78.5%, constituting the first stage of purification. Upon integration of the PEM-coated roof dome, the RE increased to 84.7%, representing the second purification capability of MWPCS. Additionally, the catalytic filter facilitated the conversion of toxic DNT into valuable diaminotoluene (DAT) with a conversion rate of 94.2%, marking the third purification stage of MWPCS. The U-SE with a white body exhibited a water evaporation rate of 2.17 kg/m 2 h, which decreased to 1.37 kg/m 2 h within the dome. However, with improved ventilation provided by the dome with holes, the evaporation rate increased to 1.85 kg/m 2 h. A high water evaporation rate-based MWPCS is anticipated to be a multistage wastewater purification system capable of effectively removing and converting water-soluble DNT.

The study explores the synthesis and versatile properties of amphiphilic magnetic particles (AMPs) achieved through sequential coatings. Modulating the hydrophobic content in the synthesis process allows for the formation of hydrophilic, amphiphilic, and hydrophobic magnetic particles, with stable AMPs synthesis achieved at a ratio of hydrophilic to hydrophobic portions of approximately 71 to 29%. These AMPs exhibited outstanding dispersion in both oil and water within an oil/water mixture. Polyethylenimine in the AMP primarily enhances the removal of hydrophilic microparticles and facilitates dispersion in water. On the other hand, octadecylamine is specifically designed for the effective elimination of hydrophobic microparticles and their dispersion in oil. AMPs demonstrated effective removal capabilities for both hydrophilic and hydrophobic microparticles in water as well as hydrophobic microparticles in 100% oil. Our approach is also suited for eliminating hydrophobic microparticles dispersed in small quantities of oil floating on large bodies of water in real-world situations.

An approach to 2,3-benzotropone from 1-benzosuberone via palladium(II)-catalyzed aerobic dehydrogenation was developed. This method first provided a catalytic route to various 2,3-benzotropones from their corresponding 1-benzosuberones in good yields. In addition, the reaction could be applied to a one-pot Diels-Alder reaction with maleimide, providing a complex benzobicyclo[3.2.2]nonenone in ≤90% yield. Kinetic analysis supporting our proposed mechanism was also performed, underscoring the robustness of the developed synthetic pathway.

Oily wastewater, a global environmental concern, demands efficient oil/water separation and pollutant removal. Our compressible separator and catalyst (CSC) balls, prepared through sponge etching and metal nanoparticle synthesis, exhibited efficient degradation of dyes of varying sizes, spanning a molecular weight range from 139 to 696 g/mol during the oil/water separation. Control over the distance between catalysts was achieved by incorporating Ag-Pt-Pd catalysts into the sponge skeleton and by adjusting the compression rates. The dispersion of the catalysts improved degradation efficiency for larger dyes, while concentrating the catalysts proved to be more effective for the smaller ones. By optimizing the compression rates of CSC balls, we successfully achieved the effective removal of emulsions of different sizes and precise control of flux. Our CSC ball-loaded system offers efficient and versatile solutions for concurrent separation and purification of emulsions and pollutants with potential environmental benefits., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

In this study, an unprecedented approach to the xanthone scaffold from cyclohexyl(2-hydroxyphenyl)methanone via dehydrogenative cyclization and a successive aromatization cascade is reported. This methodology affords a novel route to the privileged structure with a wide substrate scope (a total of 29 compounds, ≤96% yield) in a highly atom-economic manner.

Facile construction of a meta -(indol-3-yl)phenol framework with a wide substrate scope (a total of 25 compounds) via a palladium(II)-catalyzed oxidative Heck reaction and dehydrogenative aromatization in a one-step sequence is reported. This methodology affords a novel route for the privileged structures that are challenging to access via a direct link between indole and phenol, in a highly efficient and atom-economical manner.

Pseudomonas aeruginosa ( P. aeruginosa ) is an opportunistic human pathogen that forms biofilms and produces virulence factors via quorum sensing (QS). Blocking the QS system in P. aeruginosa is an excellent strategy to reduce biofilm formation and the production of virulence factors. RhlR plays an essential role in the QS system of P. aeruginosa . We synthesized 55 analogues based on the chemical structure of 4-gingerol and evaluated their RhlR inhibitory activities using the cell-based reporter strain assay. Comprehensive structure-activity relationship studies identified the alkynyl ketone 30 as the most potent RhlR antagonist. This compound displayed selective RhlR antagonism over LasR and PqsR, strong inhibition of biofilm formation, and reduced production of virulence factors in P. aeruginosa . Furthermore, the survival rate of Tenebrio molitor larvae treated with 30 in vivo greatly improved. Therefore, compound 30 , a pure RhlR antagonist, can be utilized for developing QS-modulating molecules in the control of P. aeruginosa infections.

Microbial production of many lipophilic compounds is often limited by product toxicity to host cells. Engineering cell walls can help mitigate the damage caused by lipophilic compounds by increasing tolerance to those compounds. To determine if the cell wall engineering would be effective in enhancing lipophilic compound production, we used a previously constructed squalene-overproducing yeast strain (SQ) that produces over 600 mg/L of squalene, a model membrane-damaging lipophilic compound. This SQ strain had significantly decreased membrane rigidity, leading to increased cell lysis during fermentation. The SQ strain was engineered to restore membrane rigidity by activating the cell wall integrity (CWI) pathway, thereby further enhancing its squalene production efficiency. Maintenance of CWI was associated with improved squalene production, as shown by cell wall remodeling through regulation of Ecm33, a key regulator of the CWI pathway. Deletion of ECM33 in the SQ strain helped restore membrane rigidity and improve stress tolerance. Moreover, ECM33 deletion suppressed cell lysis and increased squalene production by approximately 12% compared to that by the parent SQ strain. Thus, this study shows that engineering of the yeast cell wall is a promising strategy for enhancing the physiological functions of industrial strains for production of lipophilic compounds.

Prostate-specific membrane antigen (PSMA) is an excellent biomarker for the early diagnosis of prostate cancer progression and metastasis. The most promising PSMA-targeted agents in the clinical phase are based on the Lys-urea-Glu motif, in which Lys and Glu are α-(l)-amino acids. In this study, we aimed to determine the effect of β- and γ-amino acids in the S1 pocket on the binding affinity for PSMA. We synthesized and evaluated the β- and γ-amino acid analogues with ( S )- or ( R )-configuration with keeping α-(l)-Glu as the S1'-binding pharmacophore. The structure-activity relationship studies identified that compound 13c , a β-amino acid analogue with ( R )-configuration, exhibited the most potent PSMA inhibitory activity with an IC 50 value of 3.97 nM. The X-ray crystal structure of PSMA in complex with 13c provided a mechanistic basis for the stereochemical preference of PSMA, which can guide the development of future PSMA inhibitors.

Stereo- and regioselective formation of glycosidic linkages is a challenging topic in oligosaccharide syntheses. The stereoselective construction of 1,2- trans -glycosides generally involves neighboring group participation, which is less successful when synthesizing β-1,3-linked oligosaccharides. The combined steric effect of a 2- O -substituent and an aglycon moiety in acceptors increases the efficiency of glycosylation via neighboring group participation. This steric effect was reduced by using vicinal polyol acceptors and was demonstrated in the synthesis of 1,3-linked branched oligosaccharides.

A total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92%.

There are few hybrid positron emission tomography (PET)/fluorescence imaging agents available for brain imaging. For this purpose, BODIPY dye is very attractive because one of its fluorine atoms can be readily exchanged with 18 F, and it can be modified to produce red-shifted fluorescence. In this study, therefore, we synthesized and investigated a 18 F-labeled red-shifted BODIPY dye as a prosthetic group for brain hybrid PET/optical imaging agents and determined the optimal dose of this radioligand for hybrid imaging. The red-shifted BODIPY dye (1) was synthesized, and one of its fluorine atoms was exchanged with 18 F using SnCl 4 in high yield. Partition coefficients of 18 F-labeled BODIPY dye ([ 18 F]1) and 1 were measured using its radioactivity and fluorescence, respectively, which were shown to be suitable for brain penetration. Optimal dose for hybrid imaging was determined by analysis of PET/CT and optical images of Balb/C nude mice injected with [ 18 F]1 and 1, respectively. Hybrid PET/optical images of mice injected with optimal dose of [ 18 F]1 showed strong radioactivity and fluorescence signal in the brain at 2 min after injection, with rapid clearance by 30 min. Tissue distribution data confirmed the in vivo and ex vivo PET/optical imaging data, indicating desirable brain pharmacokinetics of the radioligand. Taken together, the results of this study suggest that [ 18 F]1 can be widely used as a prosthetic group for brain hybrid PET/optical imaging agents.

Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation. The most potent compound 41, an analog of (R)-8-gingerol with restricted rotation, showed stronger LasR-binding affinity and inhibition of biofilm formation than the known LasR antagonist (S)-6-gingerol. This new LasR antagonist can be used as an early lead compound for the development of anti-biofilm agents to treat P. aeruginosa infections.

Conjugated polymer of poly(fluorene-co-quinoxaline) was synthesized via Suzuki coupling polymerization. The emission color of the polymer can be tuned depending on the concentration of the polymer in solution. A low-energy bandgap is observed both in the concentrated solution and in the solid state, caused by aggregation of the polymer chains, resulting in long wavelength emission from the quinoxaline moiety, while short wavelength emission can be seen in diluted, well-dissolved solution. The presence of quinoxaline units enables us to demonstrate fluorescence switching and imaging. Paper-based strips containing the polymer are prepared via simple immersion of filter paper in the polymer solution for practical use in the detection of nerve agents. The emission of the paper-based strip is quenched upon exposure to diethyl chlorophosphate (DCP), a nerve agent simulant, and the initial emission intensity can be almost restored by treatment with aqueous sodium hydroxide solution, making a possible reversible paper-based sensor.

In this article, we present results of our experimental and atomistic simulation studies of the pH-dependent protonation behaviors of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(ethylenimine) (PEI). The potentiometric titration profiles of the PDMAEMA polymer and its unpolymerized monomer (i.e., DMAEMA) were measured under identical conditions in order to study the influence of the covalent linkage of the amine groups on their protonation behavior. The titration curves of poly(ethylenimine-ran-2-ethyl-2-oxazoline) (P(EI-r-EOz)) random copolymers with varying monomer composition were measured in order to study the effect of the spacing between the EI monomers on the protonation behavior of the P(EI-r-EOz) copolymer. The results of these two sets of measurements demonstrate that the connectivity and tight spacing between amine groups in a polyamine chain causes the retardation of the protonation of the amine groups relative to the same compounds in their isolated state. The same titration measurements were also performed with added NaCl. The results of these measurements demonstrate that added NaCl weakens the electrostatic repulsion between charged amine groups in a polyamine chain and thus enhances the protonation of the chain, and this effect is quite significant at a physiological NaCl concentration of 150 mM. However, on the quantitative level, the effect of added NaCl was found to be very different between the PDMAEMA and P(EI-r-EOz) cases. In PDMAEMA, since the amine groups are located at the termini of the side chains, the interaction between adjacent charged monomers occurs through the aqueous medium, and therefore at a sufficiently high concentration of added NaCl, the amine groups on the chain behave almost identically to their unpolymerized equivalents. In contrast, the electrostatic interaction between two closely spaced charged EI monomers in a P(EI-r-EOz) chain is significantly less influenced by a change of the ionic strength of the medium, because it is dominated by the local dielectric property of the polymer segment located between the charged monomers. This interpretation is further supported by ab initio electron density functional theory (DFT) calculations on model oligomeric compounds whose structures imitate the repeat unit structures of the polymers. Lastly, in connection with potential applications of the PEI and PDMAEMA polymers in gene delivery technologies, it was also examined how complexation with negatively charged polymers at the physiological NaCl concentration (150 mM) impacts the protonation behaviors of the polyamines. We found that the oppositely charged polyanion greatly stabilizes the protonated form of the amine groups on the polyamine chain. However, the proton buffering capacity of the polyamine in the complexed form under the influence of added 150 mM NaCl for the intracellularly relevant pH change was found to be significantly lower than that of the pure polyamine in the uncomplexed state with no added salt.

In order to describe the degree of interaction of a molecule with its environments by descriptors, several three-dimensional descriptors have been proposed. With the physical properties calculated around a molecule, scalar, vector, and tensor (zeroth, first, and second moments) of the physical properties were calculated and were used as descriptors for calculating the similarity index between the molecules. The tensors contain the information on the spatial distribution of those physical properties around the molecule. Hydration Free Energy Density (HFED) proposed by No et al. was used to calculate HFED tensor. The descriptors were used for the similarity index calculations between substituted benzenes and between lead compounds of HIV-1 protease inhibitors. The substituted benzenes are grouped according to the similarity indices. The grouping seems reasonable from the viewpoint of a chemical sense. The lead fragments of the HIV-1 protease inhibitors have a high similarity among themselves though their chemical formulas are not very similar, the lead fragments are diverse. Although the chemical formulas are diverse, the spatial distribution of the physical properties around the molecules is similar. The descriptors have high discriminating power in the similarity calculation between the molecules.