Structural Moieties Research Articles

One-Pot Synthesis and Characterization of 3,4-Dihydropyrimidin-2(1H)-one Derivatives using Sulphonated Reduced Graphene Oxide Nanoparticles via Biginelli Cyclocondensation and its Cytotoxic Studies

A facile one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones (4a-h) was performed in the presence of sulphonated reduced graphene oxide nanoparticles (SrGO NPs), using various substituted aromatic aldehydes (1a-h), β-keto ester (2) and urea (3). Methanol solvent mediated the reaction, under refluxing conditions. The synthesized SrGO NPs were characterized using XRD, SEM-EDS and Raman spectroscopic methods. The structural moieties of the organic compounds were confirmed by 1H NMR, 13C NMR, FTIR and Mass spectroscopic techniques. The in vitro anticancer activity of the synthesized derivatives (4a-h) was investigated using MTT (4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay as per American Type Culture Collection protocol. The cytotoxic studies were conducted against MCF-7, SKNSH human cells, using doxorubicin as the standard. Majority of the derivatives have exhibited superior anticancer activity.

Discovery of Small Molecules as Membrane-Bound Catechol-O-methyltransferase Inhibitors with Interest in Parkinson's Disease: Pharmacophore Modeling, Molecular Docking and In Vitro Experimental Validation Studies.

A pharmacophore-based virtual screening methodology was used to discover new catechol-O-methyltransferase (COMT) inhibitors with interest in Parkinson’s disease therapy. To do so, pharmacophore models were constructed using the structure of known inhibitors and then they were used in a screening in the ZINCPharmer database to discover hit molecules with the desired structural moieties and drug-likeness properties. Following this, the 50 best ranked molecules were submitted to molecular docking to better understand their atomic interactions and binding poses with the COMT (PDB#6I3C) active site. Additionally, the hits’ ADMET properties were also studied to improve the obtained results and to select the most promising compounds to advance for in-vitro studies. Then, the 10 compounds selected were purchased and studied regarding their in-vitro inhibitory potency on human recombinant membrane-bound COMT (MBCOMT), as well as their cytotoxicity in rat dopaminergic cells (N27) and human dermal fibroblasts (NHDF). Of these, the compound ZIN27985035 displayed the best results: For MBCOMT inhibition an IC50 of 17.6 nM was determined, and low cytotoxicity was observed in both cell lines (61.26 and 40.32 μM, respectively). Therefore, the promising results obtained, combined with the structure similarity with commercial COMT inhibitors, can allow for the future development of a potential new Parkinson’s disease drug candidate with improved properties.

Two structural types of dithiocarbamato-chlorido complexes of mercury(II): Preparation, supramolecular self-assembly, solid-state 13C and 15N NMR characterisation and thermal behaviour of pseudo-polymeric compounds of [Hg2(S2CNBu2)2Cl2] and [Hg4(S2CNiBu2)6][Hg2Cl6

Two new crystalline dithiocarbamato-chlorido complexes of mercury(II), [Hg2{S2CN(C4H9)2}2Cl2] (1) and [Hg4{S2CN(iso-C4H9)2}6][Hg2Cl6] (2), have been prepared and chemically identified by solution (1H, 13C) NMR and solid-state (13C, 15N) CP-MAS NMR and FT-IR spectroscopy. The crystal, molecular and supramolecular structures of these compounds were established using single-crystal X-ray diffraction (XRD) analysis. The obtained complexes reveal two principally different types of structural organisation. In the structure of the former neutral complex, there are two isomeric doubly-bridged binuclear molecules [Hg2(S2CNBu2)2Cl2] (‘A’ and ‘B’), whereas the latter compound comprises two ionic structural moieties: the tetranuclear cation [Hg4(S2CNiBu2)6]2+ and the binuclear anion [Hg2Cl6]2−. In both ionic units, pairs of iBu2Dtc or chloride ligands, which perform a bridging structural function, combine with neighbouring mercury atoms. In turn, intermolecular/interionic secondary interactions Hg···S/Hg···Cl are involved in the formation of supramolecular structures of complexes 1/2, yielding pseudo-polymeric chains of (···‘A’···‘B’···)n/(···[Hg4(S2CNiBu2)6]···[Hg2Cl6]···)n, which exhibit alternation of isomeric molecules of 1/ionic moieties of 2 along their lengths. Despite the significant structural difference between the above complexes, we established, using simultaneous thermal analysis (STA), that both exhibit very similar thermal behaviour. Moreover, during the thermal transformations of both compounds 1 and 2, the same two substances are generated: HgCl2 and HgS.

α-Glucosidase Inhibitory Activities and the Interaction Mechanism of Novel Spiro-Flavoalkaloids from YingDe Green Tea.

Flavoalkaloids are a unique class of compounds in tea, most of which have an N-ethyl-2-pyrrolidinone moiety substituted at the A ring of a catechin skeleton. 1-Ethyl-5-hydroxy-pyrrolidone, a decomposed product of theanine, was supposed to be the key intermediate to form tea flavoalkaloids. However, we have also detected another possible theanine intermediate, 1-ethyl-5-oxopyrrolidine-2-carboxylic acid, and speculated if there are related conjugated catechins. Herein, four novel spiro-flavoalkaloids with a spiro-γ-lactone structural moiety were isolated from Yingde green tea (Camellia sinensis var. assamica) in our continuing exploration of new chemical constituents from tea. The structures of the new compounds, spiro-flavoalkaloids A-D (1-4), were further elucidated by extensive nuclear magnetic resonance (NMR) spectroscopy together with the calculated 13C NMR, IR, UV-vis, high-resolution mass, optical rotation, experimental, and calculated circular dichroism spectra. We also provided an alternative pathway to produce these novel spiro-flavoalkaloids. Additionally, their α-glucosidase inhibitory activities were determined with IC50 values of 3.34 (1), 5.47 (2), 22.50 (3), and 15.38 (4) μM. Docking results revealed that compounds 1 and 2 mainly interacted with residues ASP-215, ARG-442, ASP-352, GLU-411, HIS-280, ARG-315, and ASN-415 of α-glucosidase through hydrogen bonds. The fluorescence intensity of α-glucosidase could be quenched by compounds 1 and 2 in a static style.

Exploring the Retinal Binding Cavity of Archaerhodopsin-3 by Replacing the Retinal Chromophore With a Dimethyl Phenylated Derivative.

Rhodopsins act as photoreceptors with their chromophore retinal (vitamin-A aldehyde) and they regulate light-dependent biological functions. Archaerhodopsin-3 (AR3) is an outward proton pump that has been widely utilized as a tool for optogenetics, a method for controlling cellular activity by light. To characterize the retinal binding cavity of AR3, we synthesized a dimethyl phenylated retinal derivative, (2E,4E,6E,8E)-9-(2,6-Dimethylphenyl)-3,7-dimethylnona-2,4,6,8-tetraenal (DMP-retinal). QM/MM calculations suggested that DMP-retinal can be incorporated into the opsin of AR3 (archaeopsin-3, AO3). Thus, we introduced DMP-retinal into AO3 to obtain the non-natural holoprotein (AO3-DMP) and compared some molecular properties with those of AO3 with the natural A1-retinal (AO3-A1) or AR3. Light-induced pH change measurements revealed that AO3-DMP maintained slow outward proton pumping. Noteworthy, AO3-DMP had several significant changes in its molecular properties compared with AO3-A1 as follows; 1) spectroscopic measurements revealed that the absorption maximum was shifted from 556 to 508 nm and QM/MM calculations showed that the blue-shift was due to the significant increase in the HOMO-LUMO energy gap of the chromophore with the contribution of some residues around the chromophore, 2) time-resolved spectroscopic measurements revealed the photocycling rate was significantly decreased, and 3) kinetical spectroscopic measurements revealed the sensitivity of the chromophore binding Schiff base to attack by hydroxylamine was significantly increased. The QM/MM calculations show that a cavity space is present at the aromatic ring moiety in the AO3-DMP structure whereas it is absent at the corresponding β-ionone ring moiety in the AO3-A1 structure. We discuss these alterations of the difference in interaction between the natural A1-retinal and the DMP-retinal with binding cavity residues.

Alkylverdazyls as a Source of Alkyl Radicals for Light-Triggered Cancer Cell Death.

Two alkylated verdazyl radicals (AlkVZs) were investigated as active compounds for photoinitiated controlled MCF-7 cell death. Observed results unambiguously showed that AlkVZ could be a potential structural moiety for the design of a novel family of photodynamic therapy agents. The main advantage of the proposed substances is an oxygen-independent generation of active radicals, which play a pivotal role in the treatment of oxygen-deficient tumors.

Structural Bases for Hesperetin Derivatives: Inhibition of Protein Tyrosine Phosphatase 1B, Kinetics Mechanism and Molecular Docking Study

In the present study, we investigated the structure-activity relationship of naturally occurring hesperetin derivatives, as well as the effects of their glycosylation on the inhibition of diabetes-related enzyme systems, protein tyrosine phosphatase 1B (PTP1B) and α-glycosidase. Among the tested hesperetin derivatives, hesperetin 5-O-glucoside, a single-glucose-containing flavanone glycoside, significantly inhibited PTP1B with an IC50 value of 37.14 ± 0.07 µM. Hesperetin, which lacks a sugar molecule, was the weakest inhibitor compared to the reference compound, ursolic acid (IC50 = 9.65 ± 0.01 µM). The most active flavanone hesperetin 5-O-glucoside suggested that the position of a sugar moiety at the C-5-position influences the PTP1B inhibition. It was observed that the ability to inhibit PTP1B is dependent on the nature, position, and number of sugar moieties in the flavonoid structure, as well as conjugation. In the kinetic study of PTP1B enzyme inhibition, hesperetin 5-O-glucoside led to mixed-type inhibition. Molecular docking studies revealed that hesperetin 5-O-glucoside had a higher binding affinity with key amino residues, suggesting that this molecule best fits the PTP1B allosteric site cavity. The data reported here support hesperetin 5-O-glucoside as a hit for the design of more potent and selective inhibitors against PTP1B in the search for a new anti-diabetic treatment.

Synthesis and comparative study of cytotoxicity and anticancer activity of Chalconoid-Co(II) metal complexes with 2-hydroxychalcones analogue containing naphthalene moiety

A series of six C1–C6 chalconoid based Co(II) complexes were prepared from bi-dentate 2-hydroxychalcones ligands L1-L6 containing naphthalene moiety. All synthesized metal-complexes have been evaluated to determine their cytotoxicity and anticancer activity against liver cancer cell line (Hep G2). Compared to standard 5-fluorouracil (IC50 ​= ​98.61 ​μg/mL), the metal complex C6 exhibits more potency with IC50 value 64.21 ​μg/mL against liver cancer cell line. While the remaining metal complexes such as C2, C4 and C5 are moderately active with IC50 value 314.93, 414.05 and 376.00 ​μg/mL respectively. The complexes C1 and C3 with IC50 value ​> ​1000 ​μg/mL are inadequate to display anticancer activity against Hep G2. Our perception towards the presence of organic group in the main structural moiety of complex C6 which associated with di-hydroxy (-OH) substituent at 3 and 4-position found more potent than complex C2, C4 and C5 which associated with halo (-Cl) substituent. The MTT assay revealed that the cytotoxicity and anticancer activity enhanced upon coordination of bio-ligand compared to free chalcone ligands. Therefore the present study may lead to the development of new class of anticancer drugs with structural modification.

Cytotoxic dammarane triterpenoids from the hydrolyzate of Gynostemma pentaphyllum

• Three undescribed triterpenoids with rare skeletons ( 1 - 3 ) were reported. • One unreported gypenoside ( 4 ) was isolated. • The absolute configurations were determined by ECD analysis. • Their antiproliferative effects were evaluated in a variety of cell lines. Three undescribed dammarane-type triterpenoids with rare carbon skeletons ( 1 - 3 ), together with one unreported gypenoside ( 4 ), were isolated from a acid hydrolysis product of Gynostemma pentaphyllum (Thunb.) Makino. Their molecular structures were elucidated via a combination of spectroscopic and spectrometric data, while the absolute configurations of compounds 1 , 2 and 4 were determined by electronic circular dichroism (ECD) analyse. Notably, compounds 1 - 3 possess a 19(10→1)abeo structural moiety in the A ring. Saponin 4 possesses an unusual cyclopentenone side chain. Compounds 1 , 2 and 4 were screened for their antiproliferative effects against HepG2, MCF-7 and DU145 cell lines.

Structure-based Virtual Screening of Natural Compounds as Potential Anti-Allergy Agents Against Cytokine Alarmins (TSLP and IL-33)

Background: Allergic diseases are turning into an expanding occurrence around the globe, imposing a socioeconomic burden, causing grimness and even death. Allergen encounter initiates the influx of TH2 cells, triggering the production of TH2 associated cytokines (IL-4, IL-5, and IL-13), which in turn promotes the detrimental allergic inflammation associated with asthma, allergic rhinitis, food allergy, urticaria, atopic eczema, and anaphylaxis. Cytokine alarmins (TSLP and IL-33) produced by epithelial cells play important roles in the promotion of TH2 cell development and the initiation of allergic pathogenesis. Objectives: To target cytokine alarmins (TSLP and IL-33) as novel therapeutic proteins, using natural compounds as a potential cure at an early stage of allergic diseases. Methods: Structure-based virtual screening of two large natural compounds databases (Universal Natural product Database (UNPD) and ZINC natural product database) was conducted for the identification of TSLP and IL-33 inhibitors using Autodock Vina followed by rescoring of the hit compounds. using Autodock 4.2 software. In silico physicochemical, pharmacokinetic, and toxicity analyses were conducted to assess the drug-like properties of the hit compounds. The binding mode stability of UNPD116849, ZINC01448143, and ZINC04096134 in the binding pocket of TSLP and IL-33 was probed by all-atom 50 ns molecular dynamics simulation. Results: Five natural compounds (UNPD111, UNPD116849, ZINC01448143, ZINC15957528, and ZINC04096134) containing different structural moieties (steroidal, chromone, benzodioxole, and indole) were identified to inhibit TSLP and IL-33, with limonin (ZINC04096134) found to demonstrate dual inhibitory activity potential. These compounds were found to be drug-like and toxicity-free using in silico Absorption, Distribution, Metabolism, Elimination, and Toxicity (ADME-T) prediction methods. Taken together, this study suggests the dual inhibition potential of limonin (ZINC04096134) against the cytokine alarmins. Conclusion: Five natural compounds with diverse structural moieties (steroidal, chromone, benzodioxole, and indole) were virtually identified as hit compounds against cytokine alarmins (TSLP and IL-33), with limonin showing dual inhibitory potential.

Microbially-mediated synthesis of activated carbon derived from cottonseed husks for enhanced sulfanilamide removal

This study provided a novel pathway to develop activated carbon with enhanced adsorption performance via feedstock pretreatment by fungi. The growth of Pleurotus ostreatus on cottonseed husks offered this feedstock an advantageous pore size for porous carbon making. The prepared activated carbons derived from cottonseed husks (CSH-ACs) during different fungal growth periods exhibited extraordinary performance than commercial activated carbon for sulfanilamide adsorptive removal. Their experimental data of adsorption capacities for sulfanilamide were 139.43, 146.15, and 146.16 mg g−1, respectively. The adsorption behaviors of sulfanilamide on CSH-ACs were evaluated by kinetic, isotherm and thermodynamic models. Pore filling, hydrogen-bond forming and π-π staking interactions all contributed to the rapid sulfanilamide removal. The microporous-mesoporous structure, stronger hydrophilicity, and richer functional groups moieties owing to the lignocellulose decomposition in the plant wall significantly strengthened the adsorption process on the microbial-mediated activated carbon. The effects of pH and water impurities (H2PO4-, CO32-, SO42-, Cl-, and humic acid) on sulfanilamide removal were investigated by a single factor experimental design. Results indicated that CSH-ACs were suitable for sulfanilamide removal in actual wastewater treatment with wide pH adaptability and resilience to interference.

Synthesis and Characterization of Activated Carbon Co-Mixed Electrospun Titanium Oxide Nanofibers as Flow Electrode in Capacitive Deionization.

Flow capacitive deionization is a water desalination technique that uses liquid carbon-based electrodes to recover fresh water from brackish or seawater. This is a potential second-generation water desalination process, however it is limited by parameters such as feed electrode conductivity, interfacial resistance, viscosity, and so on. In this study, titanium oxide nanofibers (TiO2NF) were manufactured using an electrospinning process and then blended with commercial activated carbon (AC) to create a well distributed flow electrode in this study. Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray (EDX) were used to characterize the morphology, crystal structure, and chemical moieties of the as-synthesized composites. Notably, the flow electrode containing 1 wt.% TiO2NF (ACTiO2NF 1 wt.%) had the highest capacitance and the best salt removal rate (0.033 mg/min·cm2) of all the composites. The improvement in cell performance at this ratio indicates that the nanofibers are uniformly distributed over the electrode’s surface, preventing electrode passivation, and nanofiber agglomeration, which could impede ion flow to the electrode’s pores. This research suggests that the physical mixture could be used as a flow electrode in capacitive deionization.

The synthesis and use of γ-chloro-enamides for the subsequent construction of novel enamide-containing small molecules

Enamides are a unique structural moiety in organic chemistry, present in numerous natural products and countless synthetic derivatives. In this report, we wish to disclose our recent work on the development of a novel, metal-free method to access trans-γ-chloro-enamides from the union of acrolein with secondary amides under mildly dehydrative conditions. Subsequent SN2 displacement of the primary alkyl chloride with a variety of nucleophiles allowed access to a number of trans-γ-functionalized-enamides. In addition to a concise substrate study, two of these derivatives were further reacted to form novel triazole products, as well as di- and trienamide-containing materials.

Noncovalently Tagged Gas Phase Complex Ions for Screening Unknown Contaminant Metabolites in Plants.

Screening the metabolites of emerging organic contaminants (EOCs) from complicated biological matrices is an important but challenging task. Although stable isotope labeling (SIL) is frequently used to facilitate the identification of contaminant metabolites from redundant interfering components, the isotopically labeled reagents are expensive and difficult to synthesize, which greatly constrains the application of the SIL method. Herein, a new online noncovalent tagging method was developed for screening the metabolites of 1H-benzotriazol (BT) based on the characteristic structural moieties reserved in the metabolites. By selecting β-cyclodextrin (β-CD) as a macrocyclic tagging reagent, metabolites with the reserved moiety were expected to exhibit a characteristic shift of the mass-to-charge ratio (Δm/z = 1134.3698) after being noncovalently tagged by β-CD. Based on the characteristic mass shift, the suspected features were reduced by 1 order of magnitude, as numerous interfering species that could not be effectively tagged by β-CD were excluded. From these suspected features, two metabolites of BT that have not been reported before were successfully screened out. The significant characteristic mass shift caused by the noncovalent tagging method is easier to identify with more confidence than the previously reported SIL method. Besides, noncovalent tagging reagents can be much more accessible and less expensive than isotopically labeled reagents. Hence, this online noncovalent tagging method can be an intriguing alternative to the conventional SIL method.

New 4-thiazolidinone/quinoline-2-ones scaffold: Design, synthesis, docking studies and biological evaluation as potential urease inhibitors

• Synthesis of two series of 6-substituted 2-quinolone 4-thiazolidinone derivatives. • The structure of the target compounds was proved by different spectroscopic together with elemental analysis. • Some compounds showed outstanding urease inhibitory with approximately ~10–50 fold more potent than thiourea. • The binding interactions of these compounds were confirmed through molecular docking studies. • The correlation between the structure moieties and urease inhibition activity was discussed. Synthesis of two series of 6-substituted 2-quinolone 4-thiazolidinone derivatives 3a-i and 4a-c was achieved. The structure of the target compounds was proved by different spectroscopic including NMR, mass and IR spectra as well as elemental analysis. All the designed final compounds exhibited varied degrees of urease inhibitory activity with IC 50 values 0.46–27.1 μM compared with the standard thiourea having which exhibit IC 50 value of 21.9 ± 0.89 μM. Compounds 3b, 3d and 3e showed outstanding urease inhibitory potential with IC 50 values of 0.92±0.17, 0.74±0.14 and 0.46±0.04 μM, respectively, which is much better than the standard thiourea. The binding interactions of these compounds were confirmed through molecular docking studies; the most active compounds displayed complete overlay and a similar binding mode and pose with the reference. Both compound 3d with the standard ligand inside the urease proteins (ID: 4UBP)

Synthesis, Characterization, Tribological and Rheological Properties of Oleyl Oleate Based Biolubricant

Oleyl oleate (liquid wax ester); is a principal component of sperm whale bubbler oil has an important industrial application such as cosmetic, pharmaceutical and biolubricant. In this work, synthesis of oleyl oleate was carried out through esterification between oleoyl alcohol and oleic acid using acidic heterogeneous catalyst, sodium hydrogen sulfate. About 95% of oleoyl oleate was produce at the optimal condition. The molecular structure of oleyl oleate has been confirmed by using FTIR, NMR and ESI-MS spectroscopies. The physicochemical properties of oleyl oleate were investigated. The results showed that the ester has pour point at -31 ± 1˚C, flash point at 320 ± 2˚C, viscosity index of 197.51 ± 1.4 and oxidative stability at 186.9 ˚C ± 1.8. Furthermore, tribological and rheological analysis of oleyl oleate were performed. Oleoyl oleate can be classified as a Newtonian fluid with having friction coefficient of 0.53 ± 0.08 at 100 ˚C operation condition. The presence of both ester functional group and long chain carbon moiety in oleyl oleate structure has a positive impact on wear protection thus plausible to be use as general purpose industrial biolubricant.

Cladosporitides A–C, three polyketides from an endophytic fungi Cladosporium tenuissimum

Three new polyketides, named cladosporitides A–C (1–3), were isolated from an endophytic fungi Cladosporium tenuissimum derived from the stem of Berberis heteropoda. Their structures were determined by extensive spectroscopic analysis including HRMS, 1D and 2D NMR data. Compound 1 possesses an unusual octahydro-2H-2,5-epoxychromene tricyclic structure moiety. An anti-inflammatory assay indicated that compounds 1–3 showed moderate inhibitory activities against LPS-induced NO production in RAW 264.7 cells with IC50 values ranging from 22.32 to 33.97 μM.

Structural Modification of Sylibin to Derivatives of Sylibin/Hydnocarpin D/Silandrin, and Evaluation of their Cytotoxicity against Cancer Cells.

Flavonolignans like silybin, hydnocarpin, and siliandrin are a group of natural compounds combining the structural moieties of flavonoid and phenylpropanoid (lignan). Hydnocarpin and silandrin have been less explored because of their trace occurrence in nature. The present study aimed at chemical conversion of silybin to hydnocarpin and siliandrin. Another objective was to synthesize a series of amide derivatives and biologically evaluate them with regard to their anti-cancer effects. In order to selectively convert silybin to 23-iodo silybin, 23-iodo hydnocarpin D and 23- iodo isosilandrin, the ratio of Ph3P, imidazole and molecular iodine was meticulously adjusted. These three iodide compounds were converted into amide compounds by chemical transformation. MTT method was applied to evaluate their anti-cancer potency. The binding affinity to related proteins was calculated by molecular docking. A total of 45 new amido-derivatives were synthesized and structurally characterized by NMR and HRMS. Some of them showed moderate to good antiproliferative potency against cancer cells. The activity of compound 10j was further testified by colony formation assay and molecular docking. The synthesis of 23-iodo silybin, 23-iodo hydnocarpin D and 23-iodo isosilandrin from silybin was successfully accomplished by one simple iodination reaction. Some of the amide derivatives of sylibin/hydnocarpin D /silandrin exhibited a remarkable inhibitory effect of proliferation on cancer cells compared to silybin. These results would pave the way for further investigation on the derivatives of flavonolignans for the treatment of cancer.

Theoretical Design of Novel Boron-Based Nanowires via Inverse Sandwich Clusters.

Borophene has important application value, boron nanomaterials doped with transition metal have wondrous structures and chemical bonding. However, little attention was paid to the boron nanowires (NWs). Inspired by the novel metal boron clusters Ln2Bn − (Ln = La, Pr, Tb, n = 7–9) adopting inverse sandwich configuration, we examined Sc2B8 and Y2B8 clusters in such novel structure and found that they are the global minima and show good stability. Thus, based on the novel structural moiety and first-principles calculations, we connected the inverse sandwich clusters into one-dimensional (1D) nanowires by sharing B−B bridges between adjacent clusters, and the 1D-Sc4B24 and 1D-Y2B12 were reached after structural relaxation. The two nanowires were identified to be stable in thermodynamical, dynamical and thermal aspects. Both nanowires are nonmagnetic, the 1D-Sc4B24 NW is a direct-bandgap semiconductor, while the 1D-Y2B12 NW shows metallic feature. Our theoretical results revealed that the inverse sandwich structure is the most energy-favored configuration for transition metal borides Sc2B8 and Y2B8, and the inverse sandwich motif can be extended to 1D nanowires, providing useful guidance for designing novel boron-based nanowires with diverse electronic properties.

Novel monomers with N‐methyl‐D‐glucamine segments and their application in structured porous materials for arsenic capture

AbstractThe N‐methyl‐D‐glucamine moieties exhibit high ability and selectivity toward arsenate ions in water by a complexation mechanism that involves their hydroxyl groups. In this work, the syntheses of two monomers containing N‐methyl‐D‐glucamine, namely 4‐vinylbenzyl‐N‐methyl‐D‐glucamine (VbNMDG), and N‐methyl‐D‐glucamine methacrylamide (MNMDG) were studied. Different synthetic routes were considered in order to obtain liquid monomers able to polymerize and selectively capture arsenic. Furthermore, the incorporation of protective groups like trimethylsilyl moieties in the molecular structure was assessed to prevent transfer reactions during further polymerization. After polymerization, hydroxyl groups were deprotected using hydrofluoric acid. Following this methodology, structured microporous polymeric films based on colloidal crystal templates were prepared. NMR and FTIR techniques were used to follow the reactions and to determine the chemical structure of the obtained products. The morphology of materials was characterized by SEM. The performances of the developed polymeric films to selectively capture arsenic were determined. Films showed an improved and reproducible sensitivity to arsenic detection exhibiting high values of arsenic capturing capability (around 90%).