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Botrytis cinerea is a phytopathogenic fungus that causes serious damage to the agricultural industry by infecting various important crops. 2-allylphenol has been used in China as a fungicide for more than a decade, and it has been shown that is a respiration inhibitor. A series of derivatives of 2-allylphenol were synthesized and their activity against B. cinerea was evaluated by measuring mycelial growth inhibition. Results indicate that small changes in the chemical structure or the addition of substituent groups in the aromatic ring induce important variations in activity. For example, changing the hydroxyl group by methoxy or acetyl groups produces dramatic increases in mycelial growth inhibition, i.e., the IC50 value of 2-allylphenol decreases from 68 to 2 and 1 μg mL−1. In addition, it was found that the most active derivatives induce the inhibition of Bcaox expression in the early stages of B. cinerea conidia germination. This gene is associated with the activation of the alternative oxidase enzyme (AOX), which allows fungus respiration to continue in the presence of respiratory inhibitors. Thus, it seems that 2-allylphenol derivatives can inhibit the normal and alternative respiratory pathway of B. cinerea. Therefore, we believe that these compounds are a very attractive platform for the development of antifungal agents against B. cinerea. [ABSTRACT FROM AUTHOR]

In this respect, the degradation of SMX was studied using a CuOx-BiVO SB 4 sb catalyst as either a photocatalyst or persulfate (sodium persulfate, SPS) activator [[14]]. The application of a solid catalyst in a removal experiment combines not only the oxidation reaction but also the adsorption of the contaminant on the catalyst surface. The most active catalyst was found to be the 0.75 CuOx-BiVO SB 4 sb , while a higher loading of CuOx delayed the degradation process. The main parameters of the degradation process, including the effect of arsenic and MTBE concentrations, catalyst mass, pH, etc., were studied. [Extracted from the article]

Two natural products, bongkrekic acid and carboxyatractyloside, are known to specifically inhibit the mitochondrial ADP/ATP carrier from its matrix side and cytosolic side, respectively, in concentration ranges of 10−6 M. In the present study, we investigated the manner of action of a synthetic bongkrekic acid derivative, KH‐17, lacking three methyl groups, one methoxy group, and five internal double bonds, on the mitochondrial ADP/ATP carrier. At slightly acidic pH, KH‐17 inhibited mitochondrial [3H]ADP uptake, but its inhibitory action was about 10 times weaker than that of its parental compound, bongkrekic acid. The main site of action of KH‐17 was confirmed as the matrix side of the ADP/ATP carrier by experiments using submitochondrial particles, which have an inside‐out orientation of the inner mitochondrial membrane. However, when we added KH‐17 to mitochondria at neutral pH, it had a weak inhibitory effect on [3H]ADP uptake, and its inhibitory strength was similar to that of bongkrekic acid. These results indicated that KH‐17 weakly inhibits the ADP/ATP carrier not only from the matrix side but also from the cytosolic side. To ascertain whether this interpretation was correct, we examined the effects of KH‐17 and carboxyatractyloside on mitochondrial [3H]ADP uptake at two [3H]ADP concentrations. We found that both KH‐17 and carboxyatractyloside showed a stronger inhibitory effect at the lower [3H]ADP concentration. Therefore, we concluded that the bongkrekic acid derivative, KH‐17, weakly inhibits the mitochondrial ADP/ATP carrier from both sides of the inner mitochondrial membrane. These results suggested that the elimination of three methyl groups, one methoxy group, and five internal double bonds present in bongkrekic acid altered its manner of action towards the mitochondrial ADP/ATP carrier. Our data will help to improve our understanding of the interaction between bongkrekic acid and the mitochondrial ADP/ATP carrier. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of Acid Red 26 was examined utilizing a graphitic carbon nitride (g-C3N4) catalyst and a UV-A light in this study. We investigated how successfully the photocatalytic approach removed Acid Red 26 from synthetic and actual municipal wastewater. Both aqueous matrices allowed for extremely high clearance rates. Wastewater degraded at a slower rate than the other matrices, this might be ascribed to the wastewater's complicated chemical composition. Using a liquid chromatography-mass spectrometry (LC-MS), the IPs in both synthetic and actual municipal effluent were determined. The photocatalytic degradation mechanisms of Acid Red 26 are hypothesised to comprise oxidation, dealkylation, and methoxy group cleavage based on the observed intermediate products (IPs). Using proven scavengers, we were also able to investigate the role of reactive species in the degradation process and illustrate the significance of h+ and O2• in the reaction. Chlorococcum sp. and Dunaliella tertiolecta microalgae were also utilised to assess the development of ecotoxicity. We observed low toxicity throughout the process when clean water was used as the matrix, with no production of hazardous IPs. In the case of actual municipal wastewater, there was an early rise in toxicity, which scientists believe was caused by the matrix's chemical make-up. To lower the toxicity, a heterogeneous photocatalysis was used, and at the end of the treatment, nearly full detoxification was obtained. [ABSTRACT FROM AUTHOR]

A series of pyrenyl and halogenated chalcone (PyBr and PyF) derivatives with different substituent groups have been constructed in this work for dye-sensitized solar cell (DSSC) applications. The compounds were synthesized using the Claisen–Schmidt condensation reaction and single crystals were successfully attained via the slow evaporation method. The existence of intermolecular interactions (C–H⋯O, C–H⋯π and π⋯π) in crystal packing was found to stabilize the crystal structure and enhance charge transfer within the molecules. UV-Vis analysis was conducted with the acetonitrile solvent to obtain the energy gap values of PyBr and PyF, which were particularly in the range suitable for photosensitizer materials used in DSSC (2.74 and 2.78 eV). The proposed compounds are situated in the appropriate HOMO and LUMO energy levels, confirming their suitability as dye sensitizer materials. Further, all compounds were investigated for solar cell performance. The fabrication of the DSSC layers was carried out and characterization using the FESEM-EDX analysis revealed the surface morphology and elemental composition of the compounds on the TiO2 layer. Owing to the D–π–A architecture and planar structure of PyBr, the compound showed an improved performance in DSSC compared with the twisted structure of PyF with the additional methoxy group. [ABSTRACT FROM AUTHOR]

The two‐step synthesis, structural, and photophysical properties of a series of heteroaryl‐substituted bis‐anil derivatives presenting aggregation‐induced emission (AIE) coupled with an excited‐state intramolecular proton transfer (ESIPT) process is described. The fluorescence color of the aggregates can be fine tuned by changing the electronic nature of the peripheral substitution, leading to a wide range of emission wavelengths (from green to the near infra‐red). Moreover, upon introduction of strong electron‐withdrawing groups such as cyano (CN), a competition between ESIPT and deprotonation is observed leading to the emission of the anionic species at low water percentage. This observation led to the synthesis of an additional mixed AIE fluorophore, functionalized by methoxy groups on one side and cyano groups on the other side. Upon addition of water, this dye displays first anionic emission, followed by typical AIE/ESIPT red fluorescence upon formation of the aggregates. TD‐DFT calculations on selected AIE dyes were performed to rationalize the nature of the emissive transitions in these derivatives. [ABSTRACT FROM AUTHOR]

In this paper, 11 compounds with five new compounds were isolated by silica gel column chromatography and repeated HPLC, and their structural characteristics were determined by NMR, high resolution mass spectrometry (HR-MS), X-ray, and circular dichroism/electronic circular dichroism (CD/ECD) data analyses. The isolated compounds were screened for antiplatelet aggregation activity, where Compounds 3-5 and 7-10 exhibited different degrees of activities with inhibition of 0.7%-15.91%, and among them, Compound 3 showed better inhibitory activity than the antiplatelet drug aspirin. Compared with Compound 1, the SP 13 sp C-NMR spectra of Compound 3 had two fewer hydroxyl carbon signals, but there were two additional olefinic carbon signals at SB C sb 149.2 (C-11) and SB C sb 109.9 ppm (C-13) in Compound 3 versus Compound 1. Compared with Compound 1, the SP 13 sp C-NMR spectra of Compound 2 were basically consistent, but the SP 1 sp H-NMR spectra had subtle differences at H-6, H-7, H-8, and H-13; therefore, we speculated that there was a configuration difference at C-7 or C-11 between Compounds 2 and Compound 1. [Extracted from the article]

Harmaline (1) and harmalol (2) represent two 3,4-dihydro-β-carboline (DHβCs) most frequently reported in a vast number of living systems. Fundamental aspects including the photosensitizing properties, cellular uptake, as well as the cyto- and phototoxicity of 1 and 2 were investigated herein. The molecular basis underlying the investigated processes are elucidated. Data reveal that both alkaloids show a distinctive pattern of extracellular DNA photodamage. Compound 1 induces a DNA photodamage profile dominated by oxidised purines and sites of base loss (AP sites), whereas 2 mostly induces single-strand breaks (SSBs) in addition to a small extent of purine oxidative damage. In both cases, DNA oxidative damage would occur through type I mechanism. In addition, a concerted hydrolytic attack is suggested as an extra mechanism accounting for the SSBs formation photoinduced by 2. Subcellular internalisation, cyto- and phototoxicity of 1 and 2 and the corresponding full-aromatic derivatives harmine (3) and harmol (4) also showed quite distinctive patterns in a structure-dependent manner. These results are discussed in the framework of the potential biological, biomedical and/or pharmacological roles reported for these alkaloids. The subtle structural difference (i.e., the exchange of a methoxy group for a hydroxyl substituent at C(7)) between harmaline and harmalol, gives rise to distinctive photosensitizing and subcellular localisation patterns. [ABSTRACT FROM AUTHOR]

Low barriers to internal rotations are especially challenging for both the experimental and theoretical determinations because they result in large tunneling splittings which are hard to assign and in potential functions that can be difficult to model. In the present work, the internal rotations of two methyl groups of 2,4-dimethylanisole were analyzed and modeled using a newly developed computer code, called ntop, adapted for fitting the high-resolution torsion-rotation spectra of molecules with two or more methyl rotors. The spectrum was measured using a pulsed molecular jet Fourier transform microwave spectrometer operating in the frequency range of 2.0–26.5 GHz, revealing internal rotation tunneling quintets with splittings of up to several gigahertz. The V3 potential barriers are 441.139(23) cm−1 and 47.649(30) cm−1 for the o- and p-methyl groups, respectively. Quantum chemical calculations predicted only one conformer with the methoxy group in the anti position related to the neighboring o-methyl group. While the results from geometry optimizations were reliable, ab initio calculations at the MP2 level did not reproduce the low torsional barriers, calling for further experiments on related systems and additional theoretical models. [ABSTRACT FROM AUTHOR]

The interest in investigating the structure and reactivity of halogen- and methoxy-substituted benzaldehydes has been motivated by the practical relevance of these substances in various fields, from the fragrance industry to agrochemicals and drug manufacturing. In this study, 3-chloro-4-methoxybenzaldehyde (3CMBA) was investigated by matrix isolation infrared spectroscopy and quantum chemistry calculations. Molecules of the compound were isolated in cryogenic argon and xenon matrices and the conformational composition of the as-deposited materials characterized by infrared spectroscopy. Two nearly degenerated conformers, differing by the orientation of the aldehyde group relatively to the chlorine ring substituent, were successfully trapped into the matrices from the room temperature vapor of the compound, the cis conformer being slightly higher in energy than the trans form. Both conformers belong to the Cs point group and have the methoxy group pointing to the opposite direction of the chlorine atom. The as-deposited matrices of 3CMBA were then irradiated by tunable monochromatic UV-light. Irradiation within the 302–299 nm range induced conversion of the cis into the trans conformer, while irradiation in the 298–296 nm range induced the inverse photoisomerization. Irradiation at higher energy (250 nm) was found to lead to decarbonylation of both conformers. Very interestingly, the observed UV-induced processes were found to take place in an essentially selective way as a function of the irradiation wavelength. In particular, the conformational isomerization reactions of 3CMBA occur with only a residual number of molecules undergoing simultaneous decarbonylation. [ABSTRACT FROM AUTHOR]

This document is a corrigendum for a scientific manuscript published in the journal Angewandte Chemie International Edition. The manuscript reports the identification of an FtsW inhibitor, but it has been discovered that the reported structures for certain compounds are incorrect. The corrigendum provides the correct structures for these compounds and also mentions a single word change in the text. Spectral data supporting the structural assignments is provided in an attached file. The authors apologize for the error. [Extracted from the article]

Xanthylium derivatives are curcumin analogs showing photochromic properties. Similarly, to anthocyanins, they follow the same multistate network of chemical species that are reversibly interconverted by external stimuli. In the present work, two new asymmetric monocarbonyl analogues of curcumin, 4-(4-hydroxy-3-metoxybenzylidene)-1,2,3,4-tetrahydroxanthylium chloride (compound 3) and 4-(4-hydroxybenzylidene)-6-methoxy-1,2,3,4-tetrahydroxanthylium chloride (compound 4) were synthesized, and their photochromic and biological properties were investigated. The UV-Vis spectroscopy and the direct and reverse pH-jumps studies confirmed the halochromic properties and the existence of different molecular species. A network of chemical reactions of these species was proposed. Furthermore, the antiproliferative properties of both compounds were evaluated using P19 murine embryocarcinoma cells and compared with each other. The results demonstrate that both new xanthylium derivatives modify the progression through the cell cycle of P19 cells, which translates into a significant antiproliferative effect. The effect of the methoxy group position is discussed and several checkpoint proteins are advanced as putative targets. [ABSTRACT FROM AUTHOR]

The aromatic biopolymer lignin, present in lignocellulosic material, can act as an antioxidant and has antimicrobial and UV blocking properties due to the presence of aromatic ring and phenolic hydroxyl groups with aliphatic hydroxyl, carboxyl, methoxy groups. It is produced in huge amounts as a by-product during the delignification process in the paper and pulp industries. Lignin-based polymer composites with advantageous properties can fulfill the growing demand for lightweight polymer composites. Incorporating lignin as reinforcement in polymer composite can make it more environmentally friendly. Among four technical lignin, kraft lignin and lignosulfonate have a unique molecular structure that includes sulfur and can be extracted from black liquor and spent liquor, respectively. Moreover, the negatively charged sulfite groups in lignosulfonate can have an electrostatic attraction to a wide range of positively charged polymers and materials, making it an ideal additive for the adsorbent material. The main intention of this review is to increase the knowledge on the use of cheap and widely available kraft lignin and lignosulfonate as reinforcement in polymer composites and to find the shortcomings to advance further research on the application of technical lignin. The article mainly focuses on advancements in kraft lignin and lignosulfonate polymer composites. [ABSTRACT FROM AUTHOR]

This work demonstrates the influence of the catalyst and alkyne nature on the regioselectivity of rhodium-catalyzed annulation of alkoxy-substituted benzoic acids (such as 3-methoxybenzoic, 3,4-dimethoxybenzoic, and piperonylic acids) with alkynes. Here, X-ray diffraction and DFT calculation data gave evidence that the observed regioselectivity is provided by both steric and coordination effects of methoxy groups. The latter is the result of weak non-covalent C–H⋯O interactions with the supporting ligand rather than with the rhodium atom. We believe that these results are also valid for other reactions of the C-H activation of methoxy-substituted arene compounds. [ABSTRACT FROM AUTHOR]

Four novel conformationally restricted (-)-muricatacin analogues, bearing a methoxy group at the C-5 position and with an alkoxymethyl group as the C-7 side chain, have been synthesised and their in vitro antiproliferative activity was evaluated against a panel of seven human tumour cell lines, as well as a single normal cell line. All analogues (9-12) showed diverse antiproliferative effects against all tested human malignant cell lines, but were devoid of any significant cytotoxicity towards the normal foetal lung fibroblasts (MRC-5). A structure-activity relationship study reveals that the introduction of tetrahydrofuran ring, the replacement of C-8 methylene group in the side chain of muricatacin analogues with the O-8 ether functionality, as well as the length of side chain may be beneficial for the antiproliferative effects of these lactones. All novel analogues were more potent than lead compound, (-)-muricatacin, against HL-60 cell line. [ABSTRACT FROM AUTHOR]

Methoxy polyethylene glycol (mPEG) is attached to many proteins, peptides, nucleic acids and nanomedicines to improve their biocompatibility. Antibodies that bind PEG are present in many individuals and can be generated upon administration of pegylated therapeutics. Anti-PEG antibodies that bind to the PEG "backbone" can accelerate drug clearance and detrimentally affect drug activity and safety, but no studies have examined how anti-methoxy PEG (mPEG) antibodies, which selectively bind the terminus of mPEG, affect pegylated drugs. Here, we investigated how defined IgG and IgM monoclonal antibodies specific to the PEG backbone (anti-PEG) or terminal methoxy group (anti-mPEG) affect pegylated liposomes or proteins with a single PEG chain, a single branched PEG chain, or multiple PEG chains. Large immune complexes can be formed between all pegylated compounds and anti-PEG antibodies but only pegylated liposomes formed large immune complexes with anti-mPEG antibodies. Both anti-PEG IgG and IgM antibodies accelerated the clearance of all pegylated compounds but anti-mPEG antibodies did not accelerate clearance of proteins with a single or branched PEG molecule. Pegylated liposomes were primarily taken up by Kupffer cells in the liver, but both anti-PEG and anti-mPEG antibodies directed uptake of a heavily pegylated protein to liver sinusoidal endothelial cells. Our results demonstrate that in contrast to anti-PEG antibodies, immune complex formation and drug clearance induced by anti-mPEG antibodies depends on pegylation architecture; compounds with a single or branched PEG molecule are unaffected by anti-mPEG antibodies but are increasingly affected as the number of PEG chain in a structure increases. [Display omitted] [ABSTRACT FROM AUTHOR]

The syntheses and crystal structures are reported of 4-phenoxy-substituted phthalonitriles with methoxy groups in the ortho- and meta-positions of the terminal benzene rings, respectively, namely, 4-(2-methoxyphenoxy)phthalonitrile and 4-(3-methoxyphenoxy)phthalonitrile, both C15H10N2O2. The https://journals.iucr.org/e/issues/2023/03/00/molecular structure was determined using the single-crystal X-ray diffraction method. It is shown that short contacts play a more decisive role in the molecular packing compared to van der Waals interactions. [ABSTRACT FROM AUTHOR]

The emergence of antibiotics-resistant bacteria has been a serious concern for medical professionals over the last decade. Therefore, developing new and effective antimicrobials with modified or different modes of action is a continuing imperative. In this context, our study focuses on evaluating the antimicrobial activity of different chemically synthesized flavonoids (FLAV) to guide the chemical synthesis of effective antimicrobial molecules. A set of 12 synthesized molecules (4 chalcones, 4 flavones and 4 flavanones), bearing substitutions with chlorine and bromine groups at the C6′ position and methoxy group at the C4′ position of the B-ring were evaluated for antimicrobial activity toward 9 strains of Gram-positive and Gram-negative bacteria and 3 fungal strains. Our findings showed that most tested FLAV exhibited moderate to high antibacterial activity, particularly against Staphylococcus aureus with minimum inhibitory concentrations (MIC) between the range of 31.25 and 125 μg/mL and that chalcones were more efficient than flavones and flavanones. The examined compounds were also active against the tested fungi with a strong structure-activity relationship (SAR). Interestingly, leakage measurements of the absorbent material at 260 nm and scanning electron microscopy (SEM) demonstrated that the brominated chalcone induced a significant membrane permeabilization of S. aureus. [ABSTRACT FROM AUTHOR]

The paper discusses the temperature dependencies of the complex dielectric permittivity obtained at different frequencies for the substituted cellulose derivatives with various concentrations of the hydroxypropoxy group. The substituted cellulose derivatives are shown to undergo a low-temperature dielectric relaxation. The input of the dielectric relaxation into dielectric permittivity decreases when the OH groups in cellulose molecules are substituted by the methoxy groups. In contrast, when OH groups in cellulose molecules are substituted by hydroxypropoxy groups, the dielectric relaxation region shifts to higher temperatures, and its intensity increases. The dielectric spectroscopy method is shown to be a reliable method to estimate the degree of the substitutions of the hydroxyl groups with hydroxypropoxy groups in the cellulose derivatives, used in the pharmaceutical industry as drug carriers and drug delivery rate regulators. [ABSTRACT FROM AUTHOR]

Molecular electrocatalysts for electrochemical carbon dioxide (CO2) reduction has received more attention both by scientists and engineers, owing to their well-defined structure and tunable electronic property. Metal complexes via coordination with many π-conjugated ligands exhibit the unique electrocatalytic CO2 reduction performance. The symmetric electronic structure of this metal complex may play an important role in the CO2 reduction. In this work, two novel dimethoxy substituted asymmetric and cross-symmetric Co(II) porphyrin (PorCo) have been prepared as the model electrocatalyst for CO2 reduction. Owing to the electron donor effect of methoxy group, the intramolecular charge transfer of these push–pull type molecules facilitates the electron mobility. As electrocatalysts at −0.7 V vs. reversible hydrogen electrode (RHE), asymmetric methoxy-substituted Co(II) porphyrin shows the higher CO2-to-CO Faradaic efficiency (FECO) of ~95 % and turnover frequency (TOF) of 2880 h−1 than those of control materials, due to its push–pull type electronic structure. The density functional theory (DFT) calculation further confirms that methoxy group could ready to decrease to energy level for formation *COOH, leading to high CO2 reduction performance. This work opens a novel path to the design of molecular catalysts for boosting electrocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • NaOH treatment enhances CH 3 O· groups migration from iron to silicon sites. • Diffusion and desorption of products on Fe-FER are promoted following alkaline treatment. • Stability of active oxygen species on Fe-FER can be controlled by NaOH treatment. The effect of desilication on the physic-chemical properties of ferrierite zeolite was investigated using spectroscopic and solid characterisation techniques including N 2 -adsorption, XRD, SEM, H 2 -TPR, NH 3 -TPD and in situ FTIR. Stability of active oxygen species formed from N 2 O over the Fe-FER catalysts and the catalytic activity for direct conversion of methane to value-added products at temperatures between 300 °C and 400 °C were studied. Ferrierite zeolites, pre-treated with 0.1 M, 0.2 M and 0.3 M NaOH solutions preserved the crystal structure of the ferrierite zeolite but their textural properties were significantly modified, leading to an increase in mesopore area and creating a greater concentration of terminal Si-OH groups, concomitant with increase in the amount of extra-framework Al and reduction in the number of bridging Si-OH-Al species. Batch-mode catalytic reaction studies of methane with N 2 O conducted in an in situ FTIR cell demonstrate that the methoxy groups formed on extraframework iron sites followed by the migration of these species to silicon defect sites, which resulted in a decline in the intensity of terminal Si-OH groups bands in the IR spectra. N 2 O-TPD experiments confirm that N 2 O is converted to N 2 , O 2 and NO over Fe-FER catalysts at 350 °C. The decline in the desorption temperature of these products observed over Fe-FER catalysts treated with alkaline solution is consistent with a significant increase in the mesopore surface area from 28.3 m2/g to 102.4 m2/g. The peak areas of desorbed O 2 and NO were estimated, and the different ratios of O 2 /NO observed on these catalysts appears to be related to the difference stabilities of surface oxygen species. Studies under continuous reaction conditions demonstrate that, at a similar level of methane conversion (ca. 2.8 %), Fe-FER catalysts prepared with the moderately alkaline solution (0.2 M NaOH) results the highest yield of methanol, dimethyl ether and formaldehyde. It is asserted that this enhanced selectivity is the result of the comparatively high concentrations of terminal silanol groups, Brønsted-acid sites, stability of active oxygen species and mesopore volume. [ABSTRACT FROM AUTHOR]

Four A2B cobalt corrole complexes 1–4 appending two methoxy or hydroxyl groups on the 10‐meso phenyl group had been synthesized. Four cobalt corroles showed high electrocatalytic activity for hydrogen evolution reaction (HER) in the organic phase and in the aqueous phase. The hydrogen evolution pathway was EECEC when using acetic acid as proton source. When trifluoroacetic acid was used as proton source, the hydrogen evolution route via EECEC or EECC depending on the concentration of trifluoroacetic acid. Cobalt corrole 4 showed the best HER performance with the kobs of 122.68 s−1 in organic phase and the TOF of 832.2 h−1 in aqueous phase respectively. The results suggested the phenyl hydroxyl group at the cobalt corrole peripheral may act as the proton relay group in HER and the o‐hydroxyl of phenyl was better than m‐ hydroxyl for proton relay. [ABSTRACT FROM AUTHOR]

Quinolinone/quinoline is one of the most unique structures in the discovery of heterocycles that have attracted much attention in the field of medicinal chemistry. The basic scaffold of fused quinoline derivatives is of great interest to medicinal chemists since large road maps of the gene and protein expression can be used to classify cancers or predict responses to certain types of treatments targeting the level of both transcription and translation and the level of enzyme activity. These specific regulations may open the door for the discovery of new drug candidates including anticancer targets. This review provides a comprehensive description of various quinolinone derivatives, especially by concentrating on compounds containing benzimidazole rings. Quinolone moieties are experimentally proven anticancer pharmacophores which may further enhance their activity due to various functional groups, mostly the electron-withdrawing groups such as fluoro, chloro, nitro, amino, and carbonyl groups that showed stronger activity than those with electron-donating groups such as methyl and methoxy groups. The presence of an electron-withdrawing or electron-donating group at the quinolone ring influences the redox properties affecting DNA synthesis. Structural motifs attributed to noteworthy inhibitory results are identified and highlighted to encourage further research and drug development. This work aims to help researchers in discovering more powerful, active, and less toxic quinoline-based anticancer drugs and developing new vision in the search for their rational design. [ABSTRACT FROM AUTHOR]

An efficient stereoselective synthesis of a pivotal intermediate, a cyclic allyl alcohol derivative containing two methoxy groups [(±)-22], using for the preparation of (±)-trans-dihydronarciclasine analogues was elaborated starting from easily available and inexpensive methyl gallate. This new synthetic route consists of 17 reaction steps, and provides an opportunity to obtain the wanted alkaloid derivative containing an additional methoxy group at position 11, in the ring A of the phenanthridone scaffold. [ABSTRACT FROM AUTHOR]

Three simple bisamide derivatives (G1, G2 and G3) with different structural modifications were synthesized with easy synthetic procedures in order to test their gel behaviour. The outcomes showed that hydrogen bonding was essential in gel formation; for this reason, only G1 provided satisfactory gels. The presence of methoxy groups in G2 and the alkyl chains in G3 hindered the hydrogen bonding between N-H and C=O that occurred G1. In addition, G1 provided thermally and mechanical stable gels, as confirmed with Tsol and rheology experiments. The gels of G1 were also responsive under pH stimuli and were employed as a vehicle for drug crystallization, causing a change in polymorphism in the presence of flufenamic acid and therefore providing the most thermodynamically stable form III compared with metastable form IV obtained from solution crystallization. [ABSTRACT FROM AUTHOR]

Rieske-type two-component vanillate O-demethylases (VanODs) catalyze conversion of the lignin-derived monomer vanillate into protocatechuate in several bacterial species. Currently, VanODs have received attention because of the demand of effective lignin valorization technologies, since these enzymes own the potential to catalyze methoxy group demethylation of distinct lignin monomers. In this work, we identified a phylogenetically divergent VanOD from Rhodococcus ruber R1, only distantly related to previously described homologues and whose presence, along with a 3-hydroxybenzoate/gentisate pathway, correlated with the ability to grow on other meta-methoxylated aromatics, such as 3-methoxybenzoate and 5-methoxysalicylate. The complementation of catabolic abilities by heterologous expression in a host strain unable to grow on vanillate, and subsequent resting cell assays, suggest that the vanAB genes of R1 strain encode a proficient VanOD acting on different vanillate-like substrates; and also revealed that a methoxy group in the meta position and a carboxylic acid moiety in the aromatic ring are key for substrate recognition. Phylogenetic analysis of the oxygenase subunit of bacterial VanODs revealed three divergent groups constituted by homologues found in Proteobacteria (Type I), Actinobacteria (Type II), or Proteobacteria/Actinobacteria (Type III) in which the R1 VanOD is placed. These results suggest that VanOD from R1 strain, and its type III homologues, expand the range of methoxylated aromatics used as substrates by bacteria. [ABSTRACT FROM AUTHOR]

Polymethoxyflavonoids (PMFs) are a large group of compounds belonging to the more general class of flavonoids that possess a flavan carbon framework decorated with a variable number of methoxy groups. Hydroxylated polymethoxyflavonoids (HPMFs), instead, are characterized by the presence of both hydroxyl and methoxy groups in their structural unities. Some of these compounds are the aglycone part in a glycoside structure in which the glycosidic linkage can involve the −OH at various positions. These compounds are particular to Citrus genus plants, especially in fruits, and they are present mainly in the peel. A considerable number of PMFs and HPMFs have shown promising biological activities and they are considered to be important nutraceuticals, responsible for some of the known beneficial effects on health associated with a regular consumption of Citrus fruits. Among their several actions on human health, it is notable that the relevant contribution in controlling the intracellular redox imbalance is associated with the inflammation processes. In this work, we aim to describe the status concerning the chemical identification and the anti-inflammatory activity of both PMFs and HPMFs. In particular, all of the chemical entities unambiguously identified by isolation and complete NMR analysis, and for which a biochemical evaluation on the pure compound was performed, are included in this paper. [ABSTRACT FROM AUTHOR]

In this work, the development of exo‐olefin compounds (R−CH2C(=CH2)Z) as chain‐transfer agents for the sulfur‐free reversible addition‐fragmentation chain transfer (RAFT) radical polymerization of methacrylates in homogeneous solution is described. A series of exo‐olefin compounds with a methyl methacrylate (MMA) dimer structure as the R group and a substituted α‐methylstyrene unit as the −CH2C(=CH2)Z (Z: Ph−Y) group were synthesized and used for the radical polymerization of MMA in toluene and PhC(CF3)2OH. These compounds underwent transfer of the CH2C(=CH2)Z group via addition‐fragmentation of the propagating methacryloyl radical. More electron‐donating (Y) substituents, such as methoxy and dimethylamino groups, produced polymers with narrower molecular weight distributions. A continuous monomer addition method further improved molecular weight control and enabled the synthesis of colorless, sulfur‐free, multiblock copolymers of methacrylates in homogeneous solutions. [ABSTRACT FROM AUTHOR]

The functionalization of the peri position of the bay chlorinated tetraazaperylene was investigated by varying the donor behavior of the substituents to assess the resulting photophysical and electrochemical properties. To accomplish this, electron donating alkyl‐ and arylsulfido substituents, methoxy and methyl groups were selectively introduced into the peri position via a nucleophilic aromatic substitution of the perchlorinated tetraazaperylene. Both the alkylated and benzylated thioethers displayed high fluorescence quantum yields of up to 80 %. Compounds from the latter group were integrated in resonant optical microcavities to achieve strong light‐matter coupling. The formation of exciton‐polaritons was observed by angle‐dependent reflectivity and photoluminescence that could be tuned by variation of the concentration of the fluorophores and of the thickness of the cavity. [ABSTRACT FROM AUTHOR]

The challenge of improving the activity of TiO2 by modifying it with metals and using it for targeted applications in microreactor environments is an active area of research. Recently, microreactors have emerged as successful candidates for many photocatalytic reactions, especially for the selective oxidation process. The current work introduces ultrasound-assisted catalyst deposition on the inner walls of a perfluoro-alkoxy alkane (PFA) microtube under mild conditions. We report Cu-Au/TiO2 and Fe-Au/TiO2 nanoparticles synthesized using the sol–gel method. The obtained photocatalysts were thoroughly characterized by UV–Vis diffuse-reflectance spectroscopy (DRS), high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and N2 physisorption. The photocatalytic activity under UV (375 nm) and visible light (515 nm) was estimated by the oxidation of lignin-based model aromatic alcohols in batch and fluoropolymer-based flow systems. The bimetallic catalyst exhibited improved photocatalytic selective oxidation. Herein, four aromatic alcohols were individually investigated and compared. In our experiments, the alcohols containing hydroxy and methoxy groups (coniferyl and vanillin alcohol) showed high conversion (93% and 52%, respectively) with 8% and 17% selectivity towards their respective aldehydes, with the formation of other side products. The results offer an insight into ligand-to-metal charge transfer (LMCT) complex formation, which was found to be the main reason for the activity of synthesized catalysts under visible light. [ABSTRACT FROM AUTHOR]

Syntheses of 6-halogen-substituted benzothiazoles were performed by condensation of 4-hydroxybenzaldehydes and 2-aminotiophenoles and subsequent O-alkylation with appropriate halides, whereas 6-amidino-substituted benzothiazoles were synthesized by condensation of 5-amidino-2-aminothiophenoles and corresponding benzaldehydes. While most of the compounds from non-substituted and halogen-substituted benzothiazole series showed marginal antiproliferative activity on tested tumor cell lines, amidino benzazoles exhibited stronger inhibitory activity. Generally, imidazolyl benzothiazoles showed pronounced and nonselective activity, with the exception of 36c which had a strong inhibitory effect on HuT78 cells (IC50 = 1.6 µM) without adverse cytotoxicity on normal BJ cells (IC50 >100 µM). Compared to benzothiazoles, benzimidazole structural analogs 45a–45c and 46c containing the 1,2,3-triazole ring exhibited pronounced and selective antiproliferative activity against HuT78 cells with IC50 < 10 µM. Moreover, compounds 45c and 46c containing the methoxy group at the phenoxy unit were not toxic to normal BJ cells. Of all the tested compounds, benzimidazole 45a with the unsubstituted phenoxy central core showed the most pronounced cell growth inhibition on THP1 cells in the nanomolar range (IC50 = 0.8 µM; SI = 70). QSAR models of antiproliferative activity for benzazoles on T-cell lymphoma (HuT78) and non-tumor MDCK-1 cells elucidated the effects of the substituents at position 6 of benzazoles, demonstrating their dependence on the topological and spatial distribution of atomic mass, polarizability, and van der Waals volumes. A notable cell cycle perturbation with higher accumulation of cells in the G2/M phase, and a significant cell increase in subG0/G1 phase were found in HuT78 cells treated with 36c, 42c, 45a–45c and 46c. Apoptotic morphological changes, an externalization of phosphatidylserine, and changes in the mitochondrial membrane potential of treated cells were observed as well. [ABSTRACT FROM AUTHOR]

As a result of our previous research focussed on benzimidazoles, herein we present design, synthesis, QSAR analysis and biological activity of novel N-substituted benzimidazole derived carboxamides. Carboxamides were designed to study the influence of the number of methoxy groups, the type of the substituent placed at the benzimidazole core on biological activity. Pronounced antioxidative activity displayed unsubstituted 28 (IC50 ≈ 3.78 mM, 538.81 mmolFe2+/mmolC) and dimethoxy substituted derivative 34 (IC50 ≈ 5.68 mM, 618.10 mmolFe2+/mmolC). Trimethoxy substituted 43 and unsubstituted compound 40 with isobutyl side chain at N atom showed strong activity against HCT116 (IC50 ≈ 0.6 µM, both) and H 460 cells (IC50 ≈ 2.5 µM; 0.4 µM), being less cytotoxic towards non-tumour cell. Antioxidative activity in cell generally confirmed relatively modest antioxidant capacity obtained in DPPH/FRAP assays of derivatives 34 and 40. The 3D-QSAR models were generated to explore molecular properties that have the highest influence on antioxidative activity. [ABSTRACT FROM AUTHOR]

Herein, we report a facile one-pot synthetic method for a new class of pyrazol-4-yl- and 2H-chromene-based substituted anilines (arenes) from ethyl 2-cyanoacetate, pyrazole aldehydes, and various nitrostyrenes in the presence of the catalyst Et3N (5 mol%) in ethanol under reflux conditions. This method requires a common organocatalyst, inexpensive starting materials, and short reaction times. A wide range of substrate scaffolds were tolerated well to afford the desired products in good to excellent yields (85–95%). Two compounds of pyrazolyl based anilines bearing the electron donating methoxy groups exhibited emissions in the redshift region and could have potential applications as fluorescence probes in biological imaging. Seven compounds of pyrazolyl based anilines bearing the electron donating methoxy and methyl groups demonstrated significant antibacterial and antifungal activity against the tested microbial strains and dermatophyte fungi, respectively. [ABSTRACT FROM AUTHOR]

Triphenylantimony(V) o-amidophenolate complexes (AP-OMe)SbPh3 (I) and (AP-C(O)Ph)SbPh3 (II) have been synthesized from N-(2-methoxyphenyl)- and N-(2-benzoylphenyl)-4,6-di-tert-butyl-o-aminophenols. The structures of the complexes in the crystalline state have been determined by X-ray diffraction (XRD) (CIF files CCDC 2205058 (I∙n-hexane) and 2205059 (II)). The Sb(1)...O(2) distances in complex I (3.018(3) Å) and Sb(1A)–O(2A) and Sb(1B)–O(2B) distances in two independent molecules A and B in complex II (2.503(3) and 2.878(3) Å, respectively) are less than the sum of the van der Waals radii of the antimony and oxygen atoms, indicating the Sb(1)...O(2) intramolecular interaction. However, the theoretical electron density studies show no interatomic interaction between the antimony atom and the oxygen atom of the methoxy group in the case of complex I but confirm these interactions in complex II. According to the Espinosa–Molins–Lecomte equation, the energy of these interactions is 11.9 and 4.1 kcal/mol for molecules A and B in complex II, respectively. [ABSTRACT FROM AUTHOR]

The possibility of obtaining volatile polynuclear heterometallic complexes containing lanthanides and transition metals bound by methoxy-β-diketonates was studied. New compounds were prepared by cocrystallization of monometallic complexes from organic solvents. Ln(tmhd)3 were used as initial monometallic complexes (Ln = La, Pr, Sm, Gd, Tb, Dy, Lu; tmhd = 2,2,6,6-tetramethylheptane-3,5-dionate) in combination with TML2 in various ratios (TM = Cu, Co, Ni, Mn; L: L1 = 1,1,1-trifluoro-5,5-dimethoxypentane-2,4-dionate, L2 = 1,1,1-trifluoro-5,5-dimethoxy-hexane-2,4-dionate, L3 = 1,1,1-trifluoro-5-methoxy-5-methylhexane-2,4-dionate). Heterometallic complexes of the composition [(LnL2tmhd)2TM(tmhd)2] were isolated for light lanthanides Ln= La, Pr, Sm, Gd, and L= L1 or L2. By single crystal XRD, it has been established that heterometallic compounds containing La, Pr, Cu, Co, and Ni are isostructural linear coordination polymers of alternating mononuclear transition metal complexes and binuclear heteroleptic lanthanide complexes, connected by donor–acceptor interactions between oxygen atoms of the methoxy groups and transition metal atoms. A comparison of powder XRD patterns has shown that all heterometallic complexes obtained are isostructural. Havier lanthanides Ln = Tb, Dy, Lu did not form heterometallics. Instead, homometallic complexes Ln(L3)3 were identified for Ln = Dy, Lu as well as for Ln = La. The thermal properties of the complexes were investigated by TG-DTA and vacuum sublimation tests. The heterometallic complexes were found to be not volatile and decomposed under heating to produce inorganic composites of TM oxides and Ln fluorides. In contrast, Ln(L3)3 is volatile and may be sublimed in a vacuum. Results of magnetic measurements are discussed for several heterometallic and homometallic complexes. [ABSTRACT FROM AUTHOR]

In order to discuss the polymerization effect from the substituted position and methoxy group of Type I photinitiators, a series of naphthalene-based oxime esters was designed and synthesized. Compared to the 2-naphthalene-substituted compound, the UV absorption region of the 1-naphthalene-based compound was greatly improved. In addition, the methoxy substitution exhibited longer absorption characteristics than did the methoxy-free one. The photochemical reaction behavior of these novel compounds was also studied by photolysis, cyclic voltammetry (CV), and electron spin resonance (ESR) experiments. Finally, the initiation abilities of naphthalene-based oxime esters toward trimethylolpropane triacrylate (TMPTA) monomer were conducted through the photo-DSC instrument under UV and a 405@nm LED lamp. Remarkedly, the naphthalene-based oxime ester (NA-3) that contains 1-naphthalene with o-methoxy substituent showed the rather red-shifted absorption region with the highest final conversion efficiency under UV (46%) and 405@nm LED (41%) lamp irradiation. [ABSTRACT FROM AUTHOR]

Bimetallic zeolitic imidazolate framework (BMZIF)-decorated Mo carbide catalysts were designed for the catalytic hydrodeoxygenation of guaiacol to produce phenol with high selectivity. A uniform layer of BMZIF was systematically coated onto the surface of the MoO3 nanorods. During carbonization at 700 °C for 4 h, BMZIF generated active species (ZnO, CoO) on highly dispersed N-doped carbons, creating a porous shell structure. Simultaneously, the MoO3 nanorod was transformed into the Mo2C phase. The resulting core@shell type Mo2C@BMZIF-700 °C (4 h) catalyst promoted a 97% guaiacol conversion and 70% phenol selectivity under 4 MPa of H2 at 330 °C for 4 h, which was not achieved by other supported catalysts. The catalyst also showed excellent selective cleavage of the methoxy group of lignin derivatives (syringol and vanillin), which makes it suitable for selective demethoxylation in future biomass catalysis. Moreover, it exhibits excellent recyclability and stability without changing the structure or active species. [ABSTRACT FROM AUTHOR]

Nitrenoid-mediated C–H insertion and cycloaddition reactions are gaining increasing importance in modern organic synthesis. However, the nitrene-mediated benzene ring expansion, which constitutes a potent tool for breaking the benzene ring, has sparely been explored for synthetic purposes. Herein we report that nitrene cycloaddition to the benzene ring can be enabled intramolecularly by iron catalysis. By using FeCl2 and N -heterocyclic carbene SIPr·HCl as the catalyst, α-azido- N -phenylamides can be converted into 1,3-dihydro-2 H -azepin-2-ones in good yields through a novel skeleton rearrangement. The rearrangement features a cascade of nitrene cycloaddition, C–N cleavage, water addition, and electrocyclic ring-opening. In the case that the N -phenyl ring is substituted with a methoxy group at the meta or para position, azepin-2-one-fused imidazolinones can also be obtained. The present reactions provide an effective method for benzene ring expansion as well as for the preparation of azepin-2-one compounds. [ABSTRACT FROM AUTHOR]

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In this research, ZnFe 2 O 4 @TiO 2 nanocatalyst was synthesized through solvothermal approach and then employed as a reusable and highly active catalyst in biodiesel synthesis from Jojoba oil. EDX, TEM, BET, CO 2 /TPD, FESEM, TGA, XRD, Raman, FTIR, and VSM analyzes were utilized to measure the structural features of ZnFe 2 O 4 and ZnFe 2 O 4 @TiO 2 nanoparticles. Also, CCD-RSM was employed to optimize effective factors on biodiesel efficiency. The uttermost biodiesel yield from Jojoba oil employing ZnFe 2 O 4 @TiO 2 nanoparticles was 97.56 %, which was obtained at temperature of 54.96 °C, catalyst concentration of 2.89 %, and MEOH/oil proportion of 12.13 mol/mol. This is the highest biodiesel efficiency ever attained from jojoba oil. Also, the reusability study showed that the ZnFe 2 O 4 @TiO 2 nanoparticles have significant stability, so that the yield of biodiesel employing this nanocatalyst was above 90 % after 7 cycles, which is a striking amount. Additionally, the biodiesel synthesis reaction utilizing ZnFe 2 O 4 @TiO 2 nanoparticles was endothermic (ΔH° =44.82 kJ/mol). Moreover, adding ZnFe 2 O 4 @TiO 2 nanoparticles to the biodiesel/petrodiesel mix resulted in improved performance of engine parameters such as BSFC, EGT, and BTE, as well as reduced CO, NO x , and UHC emissions. Furthermore, adding biodiesel to diesel declined UHC and CO emissions. Besides, HNMR and FTIR approved the existence of methyl ester methoxy group in the biodiesel structure. Owing to its high stability, remarkable biodiesel yield, and easy separation from the product, ZnFe 2 O 4 @TiO 2 nanocatalyst is recommended for use in industrial generation of biodiesel. [Display omitted] • Successful utilization of ZnFe2O4@TiO2 in biodiesel generation. • The RSM-CCD design was applied to optimize operational variables. • At optimum conditions, the biodiesel yield was achieved as 97.56 %. • The ZnFe2O4@TiO2 indicated substantial stability in 7 rounds. • Adding ZnFe2O4@TiO2 to the fuel mixture enhanced diesel engine features. [ABSTRACT FROM AUTHOR]

• Role of intermolecular hydrogen bonding interactions of freebase porphyrins with 2,4,6-trinitrophenol is analyzed. • Formation of 1:2 molecular adducts analyzed with SXRD, NMR and DFT. Three different types of meso ‑substituted freebase porphyrins (H 2 TTP, H 2 TMP and H 2 DDMP) with varied number and nature of electron donating groups (-CH 3 and –OCH 3) were synthesized. The molecular interactions of the porphyrins with different phenol derivative were explored using single crystal X-ray, NMR and their affinity by varied spectroscopic techniques. All three freebase porphyrins undergo strong intermolecular interactions with 2,4,6-trinitrophenol (TNP) and crystallized in a triclinic crystal system with iso-structural behaviour. The crystal lattices are stabilized through intermolecular hydrogen bonding interactions (N–H ∙∙∙ O and C–H ∙∙∙ O) and electrostatic interactions. Increases in the non-planarity of freebase porphyrins enhance the reactivity which results in the formation of picrate anions with 1:2 adduct formation by proton transfer process. The role of weak intermolecular interactions was analysed and quantified through Hirshfeld surface and finger print analysis. DFT studies revealed that the electron-donating effect of the methoxy group plays a major role in decreasing HOMO-LUMO gap and in-plane co-operation through the decrease in the dihedral angles. The electron density at bond critical points follows the order H 2 TTP.2TNP>H 2 TMP.2TNP>H 2 DDMP.2TNP. Absorption and emission studies showed that dramatic changes in the Soret and Q-band pattern and the binding constants were altered with different phenols of varied pKa. The stabilization of molecular adducts were analyzed in correlation with 1H- NMR study to reveal the involvement of the hydrogen bonding. [Display omitted] [ABSTRACT FROM AUTHOR]

Because of the important biological properties of β-amino acids in the present work, two new β-amino acid ethyl ester derivatives were synthesized, and their mechanistic occurrence was investigated. The title compounds were synthesized from related tetralone derivatives containing bromine and methoxy groups. Tetralone derivatives were reduced to their benzyl alcohol derivatives with NaBH 4, followed by elimination with p -toluenesulfonic acid (p TSA) to give the desired 1,2-dihydronaphthalene derivatives. The reactions of 1,2-dihydronaphthalenes with chlorosulfonyl isocyanate (CSI) afforded β-lactams. β-Amino acids were obtained from the reaction of β-lactams with EtOH in HCl. Computational studies are concerned with synthesizing four-membered lactams (β-lactam) formed by the reaction between 1,2-dihydronaphthalene derivatives and CSI. The mechanism of the formation of compounds has been elucidated using DFT at M06-2X. [Display omitted] • A total of five new compounds containing dihydronaphthalene derivative, β-lactam and β-amino acid ethyl ester derivatives were synthesized. • The mechanism of the formation of compounds has been elucidated using DFT at M06-2X. • The mechanisms proposed in this study also support the structures of β-lactams obtained in the reaction of CSI and cyclic olefins fused to the benzene ring. [ABSTRACT FROM AUTHOR]

• Pyrido-dipyrimidines (PDPs) are evaluated against different the bacteria and fungi. • The molecule with an additional OH group has better antimicrobial activity against. • S. aureus was the most sensitive bacteria. • The dominant role in the PDP- gyrase linking is played by hydrogen bonds. The escalating resistance of bacteria to multiple antibiotics utilized over many years has prompted the search for innovative antibacterial agents possessing structural attributes enabling them to overcome the resistance mechanisms. To find a new antimicrobial substance, two pyrido-dipyrimidines (A and B) are tested against ten microorganisms using the microdilution method. The key structural difference between A and B lies in their functional groups located at the meta position, A has a hydroxyl (OH) group, while B contains a methoxy group. Tested compounds possessed significant antimicrobial activity. Among tested compounds, A showed stronger antibacterial activity (MIC values ranged from 0.31 to 0.62 mg/mL) and marked antifungal activity (MIC values ranged from 0.62 to 5 mg/mL). In silico research was in good agreement with the experimental results and showed that both molecules effectively inhibit the DNA gyrases of Gram (−) bacteria, in contrast to the Novobiocin molecule. It was also shown that both considered molecules show higher inhibitory activity against the corresponding hydrolase A. niger compared to the Miconazole molecule. While the inhibitory activity of molecules A and B against oxidoreductase C. albicans is lower, it closely competes with the inhibitory activity of the Miconazole. The better antimicrobial efficacy of molecule A is supported by its previously observed strong antioxidant potential, indicating its dual activity capability. [ABSTRACT FROM AUTHOR]

Lignin commonly has a low antioxidant activity despite acting as a natural antioxidant. Most of the reported chemical reagents for enhancing lignin phenolic hydroxyl content contain halogen or metal elements, which is expensive, toxic environment and non-recyclable. Here, a cost-effective and eco-friendly technique for increasing the phenolic group content and antioxidant capability of lignin was described. Protic ionic liquids, an effective demethylating reagent with advantages of zero halogen, low cost and recyclability was applied for lignin demethylation. Quantitative 1H NMR and semi-quantitative 2D HSQC NMR analyses revealed the conversion of methoxy groups to phenolic groups. Typically, ethanolamine acetate was able to efficiently demethylate the methoxy of raw lignin at a rate as high as 44.73 %, which increased the amount of phenolic group in RL to 215.69 %. Besides, the recovery rate of [HOAc]-based protic ionic liquids and lignin was both over 90 %. The IC 50 value of organic lignin (OL) on scavenging of 2,2-Diphenyl-1-picrylhydrazyl was decreased to 0.15 mg/mL, which was better than natural or synthesized antioxidative chemicals. [Display omitted] • The demethylation process of lignin is halogen-free, cost-effective and eco-friendly. • The methoxyl group in lignin significantly decreased, and the phenolic hydroxyl group increased to 215.69 %. • The antioxidant capability of DL and OL is better than many natural or synthesized antioxidative chemicals such as BHT, natural plant extracts, polysaccharides, and synthetic antioxidants. [ABSTRACT FROM AUTHOR]

Introduction of methoxy and trifluoromethyl groups into zinc porphyrin sensitizers to improve the efficiency of dye-sensitized solar cells. [Display omitted] • In this work, we synthesized two novel self-assemblies based on the zinc porphyrin dyes ZnPx-ZnPAc (x = 1,2) and used them for dye-sensitized solar cells. • In order to enable the porphyrin dyes to have better absorption in the visible region, we introduced methoxy and trifluoromethyl groups into the upper zinc porphyrin ZnPx, respectively, with the aim of improving their optoelectronic properties. • We characterized the assembly mode by UV spectroscopy, theoretical calculations, photoelectric properties and electrochemical impedance spectroscopy, and the measurements were consistent with the conclusions. In this study, we have successfully constructed two novel self-assembled composites, the ZnPx-ZnPAc (x = 1,2), which based on zinc porphyrin derivatives, and applied them to the development of dye-sensitized solar cells. The upper dye of these self-assembly's features zinc porphyrin (ZnPx) as the core unit, while two different electron donors, methoxy (P1) and trifluoromethyl (P2), are introduced to enhance their photovoltaic properties. Photoelectrochemical studies showed that the power conversion efficiency of ZnP1-ZnPAc was superior to that of ZnP2-ZnPAc because ZnP1-ZnPAc had larger J sc and V oc , which could be attributed to the stronger electron-donating ability of methoxy than trifluoromethyl. To further validate the photoelectrochemical results, we also characterized the assembly mode by spectroscopy, theoretical calculations and electrochemical impedance spectroscopy. And the measurements were consistent with the conclusions. [ABSTRACT FROM AUTHOR]

The current production of aromatic hydrocarbons, crucial in fuel and polymer production, relies heavily on fossil resources. Finding carbon-neutral alternatives is necessary to address the current environmental challenges. Lignin emerges as a promising source for bio-based aromatics. However, existing catalytic hydrodeoxygenation processes often yield mixtures of cycloalkanes and aromatics. In our study, we investigated a selective route to obtain aromatics from phenols using the keto-tautomer reaction mechanism. According to this mechanism, the initial hydrogenation of the carbonyl group while a phenol compound is in its keto form leads to the removal of the hydroxyl group while preserving the aromatic structure. Our experiments focused on p -cresol, guaiacol, and mequinol, employing Pd/C and Ru/C catalysts. Experimental results revealed that aromatic hydrocarbons were favored during the hydrodeoxygenation of p -cresol and mequinol, while steric effects from the methoxy group hindered guaiacol's conversion. Furthermore, we observed significantly higher conversion rates when using hydrocarbon solvents compared to water, with toluene yields of up to 13.5 % by mass achieved on Pd/C. Our computational simulations confirmed the feasibility of the keto-tautomer mechanism on Pd cluster surfaces, similar to those found in Pd/C catalysts. [Display omitted] • Nonpolar solvents favor the keto-tautomer mechanism. • Decreased adsorptivity of saturated alcohols on the catalyst hinders hydrodeoxygenation. • Computational chemistry calculations confirmed the keto-tautomer mechanism on Pd surfaces. [ABSTRACT FROM AUTHOR]

HIV-1 reverse transcriptase (RT) inhibitors play a crucial role in the treatment of HIV by preventing the activity of the enzyme responsible for the replication of the virus. The HIV-1 Tat protein binds to transactivation response (TAR) RNA and recruits host factors to stimulate HIV-1 transcription. We have created a small library consisting of 4 × 6 polypyridyl Ru(II) complexes that selectively bind to TAR RNA, with targeting groups specific to HIV-1 TAR RNA. The molecule design was conducted by introducing hydroxyl or methoxy groups into an established potent TAR binder. The potential TAR binding ability was analysis from nature charge population and electrostatic potential by quantum chemistry calculations. Key modifications were found to be R 1 and R 3 groups. The most potent and selective TAR RNA binder was a3 with R 1 = OH, R 2 = H and R 3 = Me. Through molecular recognition of hydrogen bonds and electrostatic attraction, they were able to firmly and selectively bind HIV-1 TAR RNA. Furthermore, they efficiently obstructed the contact between TAR RNA and Tat protein, and inhibited the reverse transcription activity of HIV-1 RT. The polypyridyl Ru(II) complexes were chemical and photo-stable, and sensitive and selective spectroscopic responses to TAR RNA. They exhibited little toxicity towards normal cells. Hence, this study might offer significant drug design approaches for researching AIDS and other illnesses associated with RT, including HCV, EBOV, and SARS-CoV-2. Moreover, it could contribute to fundamental research on the interactions of inorganic transition metal complexes with biomolecules. A 4 × 6 combination library of TAR RNA selective binders has been constructed and molecule design and SAR have been analyzed by theoretical calculations and biochemical experiments. Key modifications were found to be R 1 = OH, R 2 = H and R 3 = Me. [Display omitted] • HIV-1 TAR RNA selective binding and Reverse transcriptase inhibition by polypyridyl Ru(II) complexes • Highly active HIV-1 RT inhibitors with low cytotoxicity to normal cells • Structure-activity relationship explored by a 4 × 6 combination library. [ABSTRACT FROM AUTHOR]

Conventionally, mesoporous silica nanoparticles are prepared by catalysing silicon alkoxides using acids or bases and are highly important in storage, delivery, and catalysis. Here, for the first time, we demonstrate that a transition metal ion (such as Ni(II), Co(II), and Mn(II)) also catalyses the hydrolysis and condensation reactions of silicon alkoxides in aqueous media without any additional acid or base to synthesize mesostructured and micro/mesostructured silica nanoparticles. An aqueous solution of a transition metal salt (specifically, nitrate salts of Ni(II), Co(II), or Mn(II), or chloride and sulphate salts of Ni(II)), 10-Lauryl ether (C 12 H 25 (OCH 2 CH 2) 10 OH, C 12 E 10) and cetyltrimethylammonium bromide (C 16 H 33 N(CH 3) 3 Br, CTAB), and tetramethyl orthosilicate (TMOS) undergoes a precipitation reaction at room temperature, yielding ultra-small ordered mesostructured silica nanoparticles. These nanoparticles are subsequently calcined to produce mesoporous silica (meso -SiO 2) with a high surface area (680–871 m2/g), large pore-volume (2.2–3.71 cm3/g), and small pore-size (1.2–3.0 nm). Moreover, the counter anions of the salts play an important role in the assembly process to obtain nanoparticles with an additional well-defined secondary pore (7.5–33.4 nm or larger). Coordinated water of the metal ion and methoxy group of the silica source react to produce a complex in which two hydroxy sides are in close vicinity to speed up the condensation reaction. We propose a hydrolysis and condensation reaction mechanism for TMOS to highlight the role of the metal ion as a catalyst. [Display omitted] • Green synthesis of mesoporous silica nanoparticles at room temperature. • Transition metal ion catalysed silica hydrolysis and condensation reactions. • Role of anions on the silica-surfactant self-assembly process. • Reaction mechanism of silica hydrolysis and condensation reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] Molecules of new lead(II) complex with methoxy-substituted beta-diketone form chains of coordination polymers in crystals. Free methoxy-groups provide a network of hydrogen bonds making the complex to develop volatility under heating only after melting. Methyl-groups in the alpha-position causes condensation of the ligands with release of new pyran derivative. New complex of lead(II) with beta-diketonate ligand PbL 2 is described, where L= CH 3 COCHCOC (OCH 3)(CH 3) 2 , 5-methoxy-5-methylhexan-2,4-dionate). Crystal structure of the compound has been determined and its thermal properties have been studied. Chains of 1D coordination polymers form crystals of the complex, where the molecules are connected through the chelate-bridging oxygen atoms, methoxy groups remain free and form hydrogen bonds between the chains. PbL 2 sublimates at 120 °C under reduced pressure (P=10−2 Torr) with partial decomposition. When heated in the condensed phase the complex decomposes with the formation of lead(II) oxide and evolution of a pyran derivative into gas phase. The mechanism of lead(II) complex thermolysis in support of the condensation of two ligands is discussed. A new organic product was identified by 13C and 1H NMR, IR and PL spectroscopy and mass spectrometry; the crystal structure of the product was determined. [ABSTRACT FROM AUTHOR]