Search

Three new tyramine-type alkamides (1-3), three new natural products (4-6), five new N-acylated/formylated aporphine alkamides with different ratios of rotational isomers (7-11), and 20 known alkamides (12-31) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of compounds 7, 8, and 10 were determined by single-crystal X-ray diffraction analysis. In the biological activity assay, compounds 3, 5, and 10-23 displayed inhibitory effects against lipopolysaccharide-induced NO release in BV-2 microglial cells, exhibiting IC50 values of 0.93-45 μM.

Three new pairs of lignan enantiomers (1a/1b‒3a/3b) and two pairs of known lignan enantiomers (4a/4b and 5a/5b) were isolated from the stems of Mappianthus iodoides. The structures of the enantiomers were elucidated by comprehensive spectroscopic analyses. Their absolute configurations were assigned by single-crystal X-ray diffraction analysis as well as comparison of the experimental and calculated ECD spectra. The antineuroinflammatory activity research revealed that compounds 2a, 2b, 3a, 4a, and 5b could moderately inhibit NO production in LPS-induced BV-2 microglial cells with IC50 values ranging from 13.42 to 48.34 μM.

Two pairs of cycloneolignane enantiomers, piperhancins A and B (1 and 2, respectively), along with two enantiomeric pairs of biosynthetic related neolignanes, hancinone C (3) and piperhancin C (4), were isolated from the stems of Piper hancei. Compound 1 is an unprecedented 1',2:1,2'-dicyclo-8,3'-neolignane. Their structures and absolute configurations were elucidated by spectroscopic analyses, X-ray diffraction, and electronic circular dichroism calculations. Among all of the isolates, compounds (+)-1, (-)-1, (+)-2, (-)-2, and (+)-3 could significantly inhibit the production of nitric oxide secreted by lipopolysaccharide (LPS)-induced neuroinflammation in BV-2 microglial cells, with IC50 values of 1.1-26.3 μM. In addition, compound (-)-1 could decrease the mRNA levels of iNOS, IL-6, and TNF-α induced by LPS in BV-2 microglial cells.

Nitrate (NO3-) is known to be actively involved in the processes of mineralization and heavy metal transformation; however, it is unclear whether and how it affects the bioavailability of antimony (Sb) in paddy soils and subsequent Sb accumulation in rice. Here, the effects of NO3- on Sb transformation in soil-rice system were investigated with pot experiments over the entire growth period. Results demonstrated that NO3- reduced Sb accumulation in brown rice by 15.6% compared to that in the control. After amendment with NO3-, the Sb content in rice plants increased initially and then gradually decreased (in roots by 46.1%). During the first 15 days, the soil pH increased, the oxidation of Sb(III) and sulfides was promoted, but the reduction of iron oxide minerals was inhibited, resulting in the release of adsorbed and organic-bound Sb from soil. The microbial arsenite-oxidizing marker gene aoxB played an important role in Sb(III) oxidation. From days 15 to 45, after NO3- was partially consumed, the soil pH decreased, and the reductive dissolution of Fe(III)-bearing minerals was enhanced; consequently, iron oxide-bound Sb was transformed into adsorbed and dissolved Sb species. After day 45, NO3- was completely reduced, Sb(V) was evidently reduced to Sb(III), and green rust was generated gradually. Thus, the available Sb decreased due to its enhanced affinity for iron oxides. Moreover, NO3- inhibited the reductive dissolution of iron minerals, which ultimately caused low Sb availability. Therefore, NO3- can chemically and biologically reduce the Sb availability in paddy soils and alleviate Sb accumulation in rice. This study provides a potential strategy for decreasing Sb accumulation in rice in the Sb-contaminated sites.

Copper selenide is widely considered to be a promising candidate for high-performance flexible thermoelectrics; however, most of the reported ZT values of copper selenides are unsatisfactory at a relatively low temperature range. Herein, we utilized some wet chemical methods to synthesize a series of copper selenides. XRD, SEM and TEM characterizations revealed that CuSe, Cu3Se2 and Cu2−xSe were prepared successfully and possessed different morphologies and sizes. Based on the analysis of their thermoelectric properties, Cu2−xSe exhibited the highest Seebeck coefficient and lowest thermal conductivity among the three samples owing to its unique crystal structure. After being sintered at 400 °C under N2 atmosphere, the electrical conductivity of Cu2−xSe enhanced considerable, resulting in a significant improvement of its ZT values from 0.096 to 0.458 at 30 to 150 °C. This result is remarkable for copper selenide-based thermoelectric materials at a relatively low temperature range, indicating its brilliant potential in the field of flexible thermoelectric devices.

Fast charge transfer and lithium-ion transport in the electrodes are necessary for high performance Li–S batteries. Herein, a N-doped carbon-coated intercalated-bentonite (Bent@C) with interlamellar ion path and 3D conductive network architecture is designed to improve the performance of Li–S batteries by expediting ion/electron transport in the cathode. The interlamellar ion pathways are constructed through inorganic/organic intercalation of bentonite. The 3D conductive networks consist of N-doped carbon, both in the interlayer and on the surface of the modified bentonite. Benefiting from the unique structure of the Bent@C, the S/Bent@C cathode exhibits a high initial capacity of 1,361 mA h g−1 at 0.2C and achieves a high reversible capacity of 618.1 m Ah g−1 at 2C after 500 cycles with a sulfur loading of 2 mg cm−2. Moreover, with a higher sulfur loading of 3.0 mg cm−2, the cathode still delivers a reversible capacity of 560.2 mA h g−1 at 0.1C after 100 cycles.

Background: Inhibition of cancer cell growth and low in vivo toxicity are two important criteria for the development of anti-cancer drugs. Curcumin is a promising candidate for developing novel anti-cancer drug analogs. The research group designed the 3,5-bis-(3,4,5- trimethoxybenzylidene)-1-methyl-piperidin-4-one analog of curcumin that significantly inhibited the growth of esophageal cancer cells in vivo. In this study, 81 curcumin analogs were synthesized, analyzed both in vitro and in vivo, and their structure activity relationships (SARs) were determined. Methods: Based on the parent structure of curcumin, 81 analogs of 3,5-bis(substitutedbenzylidene)- piperidin-4-one compounds were designed and synthesized. Their anti-cancer activity in the human cancer cell lines was evaluated using the MTT assay, and in vivo toxicity was evaluated in mice. The SARs of selected compounds were analyzed. Results and Discussion: Among the designed curcumin analogs, 61 compounds exerted anti-cancer effects higher than the parent compound in vitro; 23 compounds inhibited cell growth in the human cancer cell line at low concentrations (IC50 values below 1 μM). The acute toxicity of curcumin analogs was tested in mice; 13 compounds were selected, which did not show any obvious toxicity at doses as high as 25.0 mg/kg. The SARs of these shortlisted curcumin analogs were determined. Conclusion: Twenty-three curcumin analogs exhibiting promising in vitro anti-cancer activity and low in vivo toxicity were designed. SAR analysis indicated the optimal functional groups in the molecule required for anti-cancer activity. This study not only suggested a useful strategy to design curcumin analogs for the development of anti-cancer drugs, but also revealed a group of curcumin analogs which could be further explored.

Motivated by novel graphyne-like carbon nanostructure C68-GY, spin-polarized DFT calculations with dispersion-correction were performed to investigate the hydrogen adsorption capacity of Li decorated C68-GY nanosheet. The binding energy between Li and C68-GY was larger than the cohesive energy of bulk metal, indicating Li atoms would prefer to separately attached on C68-GY. The ab initio molecular dynamics simulation has been performed to confirm the stability of Li/C complex. When five Li atoms decorated on C68-GY, 14H2 molecules were captured. The maximum hydrogen storage density was 8.04 wt% with an average hydrogen adsorption energy of −0.227 eV per H2. The positively charged Li atoms aroused electrostatic field and induced the polarization of H2. It was notable to observe strong hybridization between the main peak of H-1s orbitals with Li below Fermi level, which was responsible for the enhancement of hydrogen binding energy, indicating its potential application on hydrogen storage.

Erosion control materials with long-term effective, economical and environmentally friendly properties play a critical role in controlling erodible and unstable sandy slopes deformed under rainfall. In this study, a novel cellulose-based curing agent was developed and applied as a sustainable sand fixation materisal. The novel cellulose-based curing agent was a dual-polymer composite material (DPCM), which was prepared by mixing two kinds of organic polymer materials: carboxymethyl cellulose (CMC) and polyacrylamide (PAM). The microstructure and composition of DPCM were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The adsorption kinetics of the curing agent on sand particles was discussed by fitting with pseudo-first-order and pseudo-second-order kinetic models. Water resistance and the compressive strength of the sand-fixing specimen at different curing ages were studied. Finally, the DPCM stabilization layer’s resistance to water erosion was investigated using a rainfall simulation test. The results demonstrated that the adsorption kinetic behavior of DPCM adsorbed on sand particles followed pseudo-second-order kinetics. Additionally, the interaction between the DPCM and sand particles was primarily hydrogen bonding, covalent bonds, and physical adsorption. The compressive stress was in the range from 53 to 915 kPa. Sandy slopes treated by DPCM showed excellent resistance to water erosion under a rainfall intensity of 120 mm/h.

For electrically conductive adhesives (ECAs), high electrical conductivity generally conflicts with excellent mechanical properties because electrical conductivity increases while desirable mechanical properties decrease with the increase in loading of conductive fillers or removal of lubricants on the silver filler surface. In this work, a method was developed to improve both the electrical conductivity and mechanical properties of the ECAs by introducing double bonds. Itaconic acid (IA) was used to replace the lubricant on the silver flake (Ag-F) surface, and acrylic acid (AA) was used as part of the ECA resin matrix. IA can replace the lubricant on the Ag-F surface, similar to other short-chain dibasic acids, to improve the ECA electrical conductivity. Furthermore, IA can be polymerized with AA to form covalent bonds between the silver flakes and the resin matrix, enhancing the mechanical properties of ECA. Compared with ECA filled with commercial silver flakes, the electrical conductivity of ECA filled with IA-treated silver flakes increased by ~ 21%, and the lap shear strength increased by ~ 29%.

Tyrosinase plays important roles in many different disease related processes, and the development of its inhibitors is particularly important in biotechnology. In this study, thirty-nine 3-/4-alkoxyphenylethylidenethiosemicarbazides were synthesized as novel tyrosinase inhibitors based on structure-based molecular design. Our experimental results demonstrated that thirty-one of them possess remarkable tyrosinase inhibitory activities with IC50 value below 1 µM, and 5a, 6e, 6g and 6t did not display any toxicity to 293T cell line at the concentration of 1000 µmol/L. According to the inhibitory activities, several compounds were selected for detail investigation on the structure-activity relationships (SARs), mechanisms of enzyme inhibition, inhibitory kinetics and cytotoxicity. In particular, the interaction between the selected inhibitors and the active center of tyrosinase was considered and discussed in detail based on their structural characteristics. Taken together, the results presented here demonstrated that the newly designed compounds are promising candidates for the treatment of tyrosinase-related disorders and further development of them may have significant contribution in biomedical science.

The hydrogen storage capacity of yttrium decorated graphyne nanotubes is calculated using spin polarized DFT method. The stabilities, electronic properties and the structures of Y attachment on graphyne tube are investigated. It is revealed that Y can be separately adsorbed on graphyne tube with the binding energy of 6.76 eV and the clustering of metal atoms is hindered. The geometry optimization shows that Y atoms decorated graphyne tube can capture 42H2 molecules through Dewar-Kubas like interaction and the polarization under the electrostatic potential formed by Y and graphyne tubes. The weight percent capacity is 5.71 wt%, with an average hydrogen adsorption energy of −0.153 eV per H2, indicating its potential application on hydrogen storage candidates.

Twenty new chebulic acid and brevifolincarboxylic acid derivatives, including eight optically pure or achiral compounds (1–7 and 14) and six pairs of enantiomers (8a/8b–13a/13b), along with nine kn...

Catalytic oxidation of formaldehyde (HCHO) at ambient temperature is an effective method for indoor HCHO removal. In this study, Ni/Co-Layered double hydroxides (LDHs) with different molar ratios were successfully synthesized via a one-step hydrothermal method. Their structure and morphology were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET)-specific surface area, X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (H2-TPR), respectively. The catalytic activity results show that Ni/Co-LDHs with the Ni/Co ratio of 1:2 exhibited enhanced activity for HCHO decomposition. The removal efficiency of indoor HCHO was up to 99.7% at ambient temperature, and it remained highly stable without any obvious deactivation even after a reaction time of 800 min. The abundant hydroxyl groups were favorable for catalytic activity, which could not only enrich the adsorption of HCHO on the surface of catalysts, but also directly react with HCHO to obtain CO2 and H2O. Moreover, the redox cycles of Ni3+/Ni2+ and Co3+/Co2+ would provide more reactive oxygen species and therefore promote catalytic reaction. This work can provide a new insight into LDH-based catalysts for low-concentration HCHO removal in practical application.

Six new quassinoids, named kumulactone F (1), kumulactone G (2), kumulactone H (4), kumulactone I (5), kumulactone J (6), and kumulactone K (7), a pair of undescribed epimers α- and β-nigakihemiacetal G (3), 15 known quassinoids (8-22), and a mixture of the known compounds α- and β-neoquassin (23) were separated from the dried stems of the medical plants Picrasma quassioides. The chemical structures of all of the new compounds were established by spectroscopic data analyses (HR-ESI-MS, 1D and 2D NMR spectroscopy, and electronic circular dichroism (ECD)). Biologically, compounds 9 and 21 showed toxicity toward the Asian citrus psyllid Diaphorina citri Kuwayama with potent activity even equal to that of the positive control (Abamectin), compound 11 exhibited an excellent neuroprotective effect against SH-SY5Y cells which were pretreated by H2O2 with potent activity equal to that of the positive control (Trolox), and none of them showed cytotoxic activity toward the HeLa or A549 cell lines (IC50 > 100 μM).

Thiol-ene click reactions are more oxygen tolerant alternative to the conventional (meth)acrylate chemistry that is frequently used for the rapid production of photopolymerized networks with numerous desirable properties. To attain a high curing efficiency while maintaining the advantages of thiol-ene systems, a castor oil-based hyperbranched urethane acrylate was employed in this work as a primary oligomer for UV-curable coating formulation. Subsequently, a tetrathiol monomer (PETMP) was introduced into the coating formulation to obtain a thiol-ene system. The effects of PETMP loadings on the UV-curing kinetics and final polymer properties were systematically investigated. Consequently, thiol-ene based films with excellent flexibility and water resistance were obtained as a result of the high efficient thiol-ene photopolymerization. The double bond conversion of the thiol-ene system was found to increase with the addition of more PETMP. Impressively, with the incorporation of 5 wt% PETMP, the resultant UV-cured film had the best acid resistance and exhibited a double bond conversion of 93.6%, a pencil hardness of 6H, a water absorption of 0.76%. Additionally, all of the prepared films were completely transparent and possessed good microstructures. These thiol-ene based films may provide insight into the preparation of high-performance UV-curable coatings with excellent flexibility.

Lignin was used herein to prepare chemical grouting materials as replacements for petroleum-based epoxy precursors. Demethylation, phenolation, and hydroxymethylation were conducted and the products were characterized via FT-IR, 1H NMR, and GPC. A quantitative NMR method was used to study the precise changes in the functional group composition. Raw lignin (RL), demethylated lignin (DML), phenolated lignin (PHL), and hydroxymethylated lignin (HML) were respectively reacted with epichlorohydrin to synthesize various lignin epoxy resin (LEP), including raw lignin epoxy resin (RLEP), demethylated lignin epoxy resin (DMLEP), phenolated lignin epoxy resin (PHLEP), and hydroxymethylated lignin epoxy resin (HMLEP). With LEP as feedstocks, new grouting materials were prepared and the effects of the RLEP content and the LEP variants were investigated. The results demonstrated that the prepared lignin epoxy grouting resin had outstanding viscosity and mechanical properties with RLEP content up to 16%, and this performance greatly exceeded the industry standard. DMLEP, PHLEP, and HMLEP were able to provide better tensile properties, heat-resistance, chemical-resistance and curing performance compared with that achieved with RLEP. Overall, lignin has displayed great potential in replacing petroleum-based materials for the preparation of high-performance chemical grouting materials.

Fluoride removal from aqueous solution by adsorption using fly ash cenospheres (FAC) modified with paper mill lime mud (LM) as composite adsorbent had been investigated. The characterization of FAC and composite adsorbent were analyzed by Scanning electron spectroscope (SEM), Energy dispersive spectrometer (EDS), Brunauer emmett teller (BET) and Fourier transform infrared (FTIR), which demonstrated that the porous structure of composite adsorbent was obtained after surface modification. Adsorption of fluoride on modified fly ash cenospheres was fitted with pseudo-second-order model and Langmuir model. Response surface methodology (RSM) was employed to investigate the effects of F− concentration, pH, adsorbent dosage and temperature on the removal efficiency. Analysis of variance (ANOVA) was used to test the adequacy of the mathematical models. The Nonelectrostatic model of modified fly ash cenospheres adsorbing fluoride was built through the Generalized composite method, indicating that two inner-spherical complexes, ≡SF and ≡SOHF−, were formed in the adsorption process by means of the ligand exchange and surface complexation. Optimization of the adsorption conditions enabled the realization of the practical needs for fluoride contaminated water.

The structural, elastic, mechanical and thermodynamic properties of α, β, and h-CuGaO2 were investigated based on first-principles calculations. The obtained lattice parameters were in good...

Selective oxidation of sulfides into sulfoxides or sulfones is an important transformation in organic synthesis. Activated carbon supported Nb-based catalysts were prepared by the impregnation method and then characterized by the XRD, TEM and XPS. The characterization results indicate Nb species is amorphous Nb2O5. The catalysts were applied for the catalytic oxidation of sulfides in aqueous phase with H2O2 as the oxidant. Sulfides could be converted into the corresponding sulfoxides or sulfones with high conversion and selectivity at room temperature. The recycling experiments showed the Nb2O5/AC catalysts exhibited good reusability. They could be recycled for 10 times without obvious loss of activity and selectivity.

A new chlorinated diphenyl ether, ethyl dichloroasterrate (1), and a new sesquilignan, mappilignan A (2), along with two known diphenyl ethers (3 and 4) and one known sesquilignan (5), were isolated from the stems of Mappianthus tomentosus. The structures of 1−5 were assigned by spectroscopic data analysis and by comparison with literature data. The absolute configuration of 2 was established using experimental and calculated ECD data. Compound 2 displayed inhibition of nitric oxide production in lipopolysaccharide (LPS)-induced BV-2 microglial cells, with IC50 value of 38.87 ± 2.27 μM.

A novel hydrolysable cationic monomer of quaternary ammonium dialkyl maleate was synthesized and subsequently copolymerized with acrylic acid and isobutenyl polyethylene glycol to successfully yield an amphoteric polycarboxylate superplasticizer (APC). The effects of the APC on cement particles were systematically investigated. The fluidity, fluidity retention and mechanical properties were measured to evaluate the performances of the APC and compared with those of a polycarboxylate superplasticizer (PCE). In addition, X-ray diffraction, thermogravimetric and scanning electron microscopy characterization were performed to investigate the influences of the APC on cement particles from microscopic level. Furthermore, the interactions of the APC with cement particles were also investigated via adsorption, hydration heat and zeta potential measurements. It was found that the introduction of a hydrolysable cationic monomer could improve the micro-structure and delay the hydration of cement. Moreover, the APC could increase the cement paste fluidity and fluidity retention.

Fluorescein has been found as an efficient visible-light-induced oxidase mimic and its catalytic performance is group-dependent. Herein, a facile colorimetric strategy for β-galactosidase (β-gal) was developed using fluorescein di β-D-galactopyranoside (FDG) as a probe based on the analyte induced change in oxidase mimicking activity of fluorescein derivatives. FDG doesn’t possess any visible-light-induced oxidase activity and can generate fluorescein and fluorescein mono β-D-galactopyranoside (FMG) in the presence of β-gal. The in situ generated fluorescein and FMG possess high oxidase-like activities under visible-light illumination and could catalyze the oxidation of 3, 3′, 5, 5′-tetramethylbenzidine (TMB) upon short irradiation by light-emitting diode (LED) lamp. Thus, the β-gal activity can be selectively detected in linear range from 0.10 to 12.9 μg mL−1 with a limit of detection (LOD) of 0.04 μg mL−1. We further integrated with the visual detection of α-fetoprotein antigen (AFP) based on the corresponding colorimetric signal induced by β-gal-linked colorimetric immunoassay, a LOD of 0.08 ng mL−1 could be achieved. Significantly, our proposed assay provides a facile sensing platform based on the change in enzyme mimicking activity induced by analytes. In addition, this optical method works without complex synthesis procedure and efficiently avoids participation of unstable H2O2 as an oxidant. Therefore, the present work not only shows the excellent assay performance in β-gal and tumor biomarker detection, but also opens up a new avenue for its application in practical optical sensing.

Two new steroidal glycosides oxystauntoside A (1) and oxystauntoside B (2), together with sixteen known compounds (3–18) were isolated from the 95% ethanol extract of Merrillanthus hainanensis. Their structures were characterized by extensive spectroscopic analysis including NMR and mass spectra and single crystal X-ray crystallography. The absolute configuration of 1 and 2 were further determined by ECD calculations. All of these compounds were isolated from M. hainanensis for the first time. All the fractions and compounds were tested for the anti-inflammatory activity against the TNF-α factor. The ethyl acetate fraction showed the most potent inhibition (71.3%) at 10 μg/mL and compounds 5 (78.9%) and 9 (73.4%) in this fraction with both carboxyl and phenolic hydroxyl groups showed significant inhibition at 10 μM. Our study provided the first scientific report for the medicinal value of M. hainanensis.

Four new diterpenoids (1–4), three new triterpenoids (12–14), and seven known diterpenoids (5–11) were obtained from an aqueous EtOH extract of the aerial parts of Triadica rotundifolia. The structures of new compounds were determined by spectroscopic techniques. Their absolute configurations were verified via single-crystal X-ray diffraction data, Mo2(OAc)4 induced electronic circular dichroism (ECD), and ECD calculations. The antineuroinflammatory effects of the isolates were assessed by inhibiting NO production in LPS-induced BV-2 microglial cells. Compared with the positive control minocycline (IC50 = 16.1 μM), compounds 3, 8, 11 showed moderate inhibitory activities with IC50 values of 35.9, 17.0, 31.5 μM, respectively.

In this study, by incorporating imide-fused benzothiadiazole (BIBT) as the electron-withdrawing core unit, for the first time we designed and synthesized a novel A1–D–A2–D–A1 type small molecule acceptor denoted BIBT-NI for organic solar cell (OSC) applications. Its thermal, optical and electrochemical properties were thoroughly investigated. Density functional theory was also applied to shed light on the molecular configuration and energy level distribution of the acceptor. This molecule exhibited a strong absorption spectrum in the range of 420–550 nm together with an optical bandgap of 2.04 eV. The inverted OSC devices based on BIBT-NI as an electron-acceptor combined with the classical polymer poly(3-hexylthiophene) (P3HT) as an electron-donor afforded an optimal power conversion efficiency of 2.11% with a comparatively high open-circuit voltage of 0.78 V. These results underscore the promising potential of BIBT as an electron-deficient building block in constructing nonfullerene acceptors for OSCs.

This work aims to explore the feasibility of self-matting coatings based on soybean oil. A novel reactive waterborne polyurethane (RWPU) dispersion containing unsaturated CC double bonds was synthesized from epoxidized soybean oil (ESO). Subsequently, the RWPU dispersion was copolymerized with hard/soft monomers at different weight ratios to prepare polyurethane/acrylate (MPU) hybrid emulsions. The results reveal the gloss levels of MPUs to be as low as 3.3 gloss units at 60°. A scanning electron microscope and three-dimensional surface profilometer were employed to observe the morphology of the MPU-based films, and the relation between the surface roughness and gloss was determined. Further, thermal gravimetric analysis was conducted to determine the thermal stability of the MPU-based films, and the results denoted that these MPU-based films exhibited excellent thermal stability. Tensile tests indicated that the RWPU dispersion, which was copolymerized at a hard monomer weight of 30%, exhibited a good tensile strength of 13.2 MPa and a high elongation percentage of 578%. Furthermore, after one year, the MPU emulsions exhibited a narrow particle size distribution and their zeta potential values were approximately −30.0 mV, revealing the excellent storage stabilities (>one year) of all the MPU emulsions.

Two new cadinane sesquiterpene glucosides (1, 2), two new phenylpropanoid glycosides (3, 4), and two new diterpenoid glucosides (5, 6), as well as 6 known compounds were isolated from the stems of Tinospora sinensis. The structures of these compounds were elucidated by extensive spectroscopic analysis and chemical methods. The absolute configuration of compound 1 was determined by timedependent density functional theory (TDDFT) electronic circular dichroism (ECD) calculations and in situ dimolybdenum CD method. All the isolated compounds except for compounds 7, 11 and 12 were evaluated for their anti-neuroinflammatory effect by inhibiting the nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine BV-2 microglial cells, and compound 4 showed anti-neuroinflammatory activity with IC50 values 42.90 μM in vitro assay.

Synthesis, characterization, and coating performance of castor oil (CO)-based waterborne hyperbranched polyurethane acrylate (WHPUA) emulsions are highlighted in this work. Herein, a second-generation CO-based hyperbranched polyester (C20) was synthesized by introducing the renewable CO as a B3 core and dimethylolpropionic acid as an AB2 monomer via a pseudo-one-pot condensation procedure. Three types of CO-based WHPUA emulsions were prepared through the addition of the hyperbranched C20 with maleic anhydride (MA) and the isocyanate-bearing semiadduct (IPDI-HEA) at different MA/IPDI-IH molar ratios without the addition of any emulsifiers. The prepared emulsions were further formulated into UV-curable coating formulations and exposed to a medium-pressure mercury lamp. Consequently, the obtained UV-cured coatings exhibited outstanding adhesion performance, excellent transparency, and an acceptable degree of final double bond conversion. Owing to a relatively low concentration of hydrophilic units and a large number of acrylate functionalities in the waterborne oligomer, the obtained films were endowed with high crosslinking density and low hydrophilic nature, thus producing enhanced tensile strength, pencil hardness, water resistance, and chemical resistance. Due to their combination of renewable materials, a waterborne system and a UV-curing technique, these CO-based WHPUA emulsions offer promising opportunities to be used as environmentally friendly coatings.

Photoresponsive complex emulsions are prepared in a three-phase system consisting of two oils: hexane (H) and perfluorooctane (F). An aqueous solution of a mixed surfactant of fluorosurfactant, F(CF2)x(CH2CH2O)yH (Zonyl FS-300), and a synthesized light-responsive surfactant, 2-(4-(4-butylphenyl)diazenylphenoxy)ethyltrimethylammonium bromide (C4AZOC2TAB) was employed as the continuous phase. Complex emulsions with various geometries were prepared by one-step vortex mixing and a temperature-induced phase-separation method. It was noticed that the topology of the complex emulsion was highly dependent on the mass ratio of Zonyl FS-300/C4AZOC2TAB. Light microscopy images showed that phase inversion from an H/F/W- to an F/H/W-type double emulsion via a Janus emulsion was achieved by gradually increasing the mass ratio of C4AZOC2TAB/Zonyl FS-300. Upon UV/blue light irradiation, the topology of complex emulsions was turned to switch from an F/H/W double emulsion to a Janus emulsion to an entirely inverted H/F/W d...

Two previous undescribed cyclic pentapeptide-type compounds (1–2), with two known ones (3–4), were first isolated and purified from Clerodendrum japonicum (Thunb.) Sweet. Their structures were elucidated by extensive spectroscopic data (1D and 2D NMR) analysis. The absolute configurations of the two compounds were assigned using a combination of Marfey’s method and HPLC-MS analysis. All four compounds showed weak cytotoxicity against four human cancer cells lines (T24, A549, HepG2, MGC-803), with IC50 values ranging from 23.8 to 39.6 μM.

Block copolymers (BCPs) have stimulated widespread research interest due to their applications as facile templates in the fabrication of optimized thermosets with micro– or nanostructured morphologies. In the present work, a novel block copolymer was obtained from a commercial poly(styrene-block-butadiene-block-styrene) (SBS) triblock copolymer precursor by a two-step process including reaction with hydrogen peroxide in a water/dichloroethane biphasic system to achieve an epoxidized derivative with a 46 mol% degree of epoxidation (thus denoted as eSBS46), which was then followed by reaction with 1-(2-aminoethyl)piperazine (AEP, thus yielding eSBS46-AEP) as a reactive functional group that was incorporated to prepare nanostructured epoxy thermosetting blends. As a result of the oxirane ring-opening achieved (to a conversion degree of 10 mol%) by reaction with AEP, the nanostructured morphology was converted from spherical micelles in the case of eSBS46 to branched wormlike micelles for eSBS46-AEP. ...

A novel waterborne polyurethane (WPU) resin with low gloss and micro-roughness was synthesized by the prepolymer and self-emulsification method. It was achieved by introducing multi-hydroxyl castor oil and reactive bisphenol A-type epoxy E-44 or E-51 resin to polyurethane prepolymer to form a cross-linking network structural waterborne polyurethane emulsion, which demonstrated the distinctive characteristic of the shear-thinning pseudoplastic fluid with a yield stress. The chemical structures and rough surface morphologies of the WPU films were characterized by FTIR-ATR, LCRS, AFM, SPMS and SEM, respectively. The specular gloss values at 20°, 60° and 85° incident angles were measured, and the values of different kinds of roughness parameters were obtained. The relationship between the gloss and the castor oil content was also discussed in detail. In general, this WPU resin endowed the film with micro-roughness, moderate hardness and good adhesive strength, making it very prospective in substitution for the traditional low gloss coatings.

A novel environmentally friendly method was developed to fabricate hollow core–shell conductive nanoparticles using a natural and nontoxic material, nanocrystalline cellulose (NCC), as the template. The NCC used in this study has nano-scale rod-like structure. After the oxidization to dialdehyde cellulose, the insulated NCC was functionalized by poly(dopamine) (PDA) in weakly alkaline conditions through Schiff base reaction and self-polymerization. The Schiff base can be hydrolyzed in an aqueous acetone solution via ultraviolet radiation so that the hollow structure constructed. This structure not only strengthened the mechanical properties but also provided more active sites for silver deposition. Utilizing the chelating ability of the catechol groups in PDA, electroless plating method was used to form the silver coating layer. Scanning electron microscope and Dynamic Light Scattering measurements indicated that these nanoparticles (NPs) had well-defined morphology and a mean diameter of 100–120 nm. Moreover, these prepared Ag–DA–NCC0 NPs exhibited excellent conductivity. Their electrical resistivity reached 0.2 mΩ·cm, which is much higher than that of many other conductive particles used in conductive adhesive.

Castor oil (CO) based hyperbranched urethane acrylates (HBUAs), namely C10-IH and C20-IH, were synthesized by modifying the hydroxyl groups of first (C10)- and second (C20)-generation of CO-based h...

Six previously undescribed oleanane-type triterpenoid saponins, fortunosides A–F, together with six known ones, were isolated from the aerial parts of Lysimachia fortunei Maxim. Their structures were established by spectroscopic data analyses (1D, 2D-NMR and HRESIMS) and chemical methods. All isolated triterpenoid saponins were evaluated for their cytotoxicity against four human liver cancer cell lines (SMMC-7721, Hep3B, HuH7, and SK-Hep-1). Three saponins with the aglycone protoprimulagenin A exhibited moderate cytotoxicity against all of the tested human cancer cell lines, with IC50 values ranging from 4.76 to 15.12 μM.

A series of low gloss waterborne polyurethane acrylate (WPUA) hybrid emulsions with different weight ratios of hard/soft monomers of acrylic monomers were synthesized successfully. Compared with the traditional low gloss coatings that achieve low gloss effects by adding a large number of pigments, fillers or both to roughen the surfaces, the low gloss effect of these WPUA emulsions was achieved through the formation of self-roughed surfaces during film formation with zero loading of extraneous dulling agent. Gloss levels could be as low as 3 units at 60° incident angle. The chemical structures of these WPUA films were characterized by nuclear magnetic resonance carbon spectroscopy ( 13 C NMR), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The rough surface topographies of these WPUA films were observed by scanning electron microscopy (SEM). The particle size distributions of these WPUA emulsions were analyzed by DLS measurement. The polymeric phase separation behaviors of these WPUA films were assessed by DSC analysis. In general, the WPUA emulsions that afforded films with good hardness, good adhesion strengths and excellent thermal stabilities, showed a great advantage in applications of low gloss aqueous coating.

This paper reports on a novel self-matte or bulk-matte waterborne polyurethane coating composite with inherently extremely low gloss. The coating composite was comprised of a siloxane-containing waterborne polyurethane (SPU) resin and a crosslinked waterborne polyurethane (CPU) resin. The CPU resin was mainly responsible for fabricating the micro-rough surface of the film, which was achieved by a crosslinking reaction between the waterborne polyurethane and bisphenol A-type epoxy E-44 resin. The SPU resin was used to improve the comprehensive properties of the film, which was ascribed to the addition of silane coupling agent KH792. Compared with traditional matte coatings, this coating composite made it possible to avoid high loadings of matting agent and to arrive at highly flexible low-gloss finishes. Gloss levels of as low as a few tenths of a percent, even at high incidence angles, have been achieved with zero loading of extraneous dulling agent. The chemical structures of the SPU and CPU resins were characterized by FTIR-ATR and NMR spectra. The micro-rough topographies and surface rough degrees of the SPU, CPU and their 50%/50% composite films were measured by SEM and MSP, respectively. The particle sizes and particle morphologies of the SPU and CPU resins were imaged by TEM. Finally, the comprehensive properties of the SPU, CPU and their 50%/50% composite resins were evaluated, including the water contact angle, film transparency, tensile strength and storage stability.

We prepared poly(N-isopropylacrylamide-co-4-tert-butylcalix[8]arene) (PNIPAM-TBCX) hydrogels by copolymerization of N-isopropylacrylamide (NIPAM) with 4-tert-butylcalix[8]arene (TBCX) to capture hazardous pentachlorophenol (PCP) from aqueous solution. Adsorption experiments showed that the adsorption capacities of PNIPAM-TBCX hydrogels reached 1.96, 2.08 and 2.02 mg PCP per 1 g of hydrogel, while the molar percentage ratio of TBCX in the hydrogels was as low as 0.5%, 0.7% and 1%. The equilibrium adsorption of PCP on the hydrogels was studied using different adsorption models. In addition, the PNIPAM-TBCX hydrogel still retained its performance when regenerated several times by immersing in water at 323 K.

Through inserting SiO2@Au into the reduced graphene oxide (rGO) layers, the rGO-SiO2@Au composites were prepared via the vacuum-assisted electrostatic self-assembly method. The obtained composites exhibit excellent electromagnetic interference (EMI) shielding effectiveness due to the successful construction of multi-nanocavities (spherical SiO2 cavities and layered air cavities between rGO), multi-reflection interfaces (rGO and Au shell) and continuous conductive network (rGO-Au-rGO). Among them, the total shielding effectiveness (SET) of the composites with 75.78 wt% SiO2 and 19.38 wt% rGO can reach 38.4 dB at 18 GHz. Thereinto, the shielding effectiveness absorption (SEA) is 36.4 dB, 1.3 and 13.5 times higher than that of rGO and SiO2@Au. And the shielding effectiveness reflection (SER) is always below 5 dB from 1 to 18 GHz, much lower than that of rGO (about 15 dB). Further studies found that the SEA values were enhanced at 12.6 GHz and 6.2 GHz due to the construction of cavities and location of Au nanoparticles between the rGO layers. This study provides a simple and mild method to prepare high-performance thin-layered materials with applications in the field of EMI absorption shielding.

A further phytochemical investigation of the aerial parts of Lysimachia foenum-graecum Hance led to the isolation of three new oleanane-type triterpenoid saponins, foegraecumosides L–N ( 1 – 3 ), along with one known saponin, 3- O - β - d -glucopyranosyl-(1 → 2)-α- l -arabinopyranosyl-cyclamiretin A ( 4 ). Their structures were elucidated by spectroscopic data analyses and chemical methods Compounds 1 − 4 were evaluated for their cytotoxicity against NCI-H460, MGC-803, HepG2, and T24 human cancer cell lines, and compound 4 showed moderate activity against all tested cell lines. Furthermore, the cytotoxicity of compound 4 was tested on drug-sensitive and drug-resistant lung cancer cell lines (A549 and A549/CDDP, respectively).

Manganese dithionate (MnS2O6), formed in the leaching process of pyrolusite slurry with SO2, is a concern because of its ability to decrease the purity of MnSO4 (industrial raw material). Information regarding the oxidation and recovery of dithionate ion is scarce. In this study, we investigated the leaching process of MnO2 with MnS2O6 in the liquid phase. The leaching reaction presented one way to oxidize MnS2O6. The most suitable operating parameters on the oxidation efficiencies of MnS2O6 were established as follows: MnO2 dosage, 21.7 g L−1; agitation speed, 450 rpm; initial H2SO4 concentration, 1.81 mol L−1; initial MnS2O6 concentration, 28.5 g L−1; and reaction temperature, 372.5 K. Under the optimum conditions, the removal efficiency of 97.55% for MnS2O6 was obtained in 30 min. The experimental results showed that increasing the initial concentrations of MnS2O6 and H2SO4 and the reaction temperature resulted in a decrease in the content of MnS2O6. The dithionate oxidation process could be well modeled by the shrinking core model with an inert product layer, which indicated that the process was controlled by the interfacial chemical reaction. The reaction orders with respect to initial H2SO4 concentration and initial MnS2O6 concentration were 1.64 and 0.18, and the activation energy was 60.1 kJ mol−1 as well as pre-exponential factor was 5.9 × 106.

For various applications, it is essential to enhance the colloidal stabilization of carbon nanotube (CNT) dispersions. Here, the polymers with carbazole pendants of poly(4-(N-carbazolyl)methylstyrene-bl-poly(ethylene glycol) methyl ether methacrylate) (PCMS5-b-PAPEG73 and PCMS16-b-PAPEG43) and PCMS30, synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization, were used for noncovalent functionalization of multiwalled carbon nanotubes (MWCNTs) in tetrahydrofuran (THF), offering efficient colloidal stabilization. Meanwhile, the adsorption of polymers onto MWCNTs was investigated. The results showed that the MWCNTs decorated with these three polymers in THF exhibited different colloidal stabilization and adsorption capacity. Moreover, the MWCNT dispersions could be stabilized for days and their colloidal stabilization elevated with the increase of polymer concentrations. The block copolymer PCMS16-b-PAPEG43 exhibited the optimal adsorption and dispersion capability for MWCNTs. The...

In this study, novel macro porous Ni2+-imprinted chitosan foam adsorbents (F-IIP) were prepared using sodium bicarbonate and glycerine to obtain a porogen for adsorbing nickel ions from aqueous solutions. The use of the ion-imprinting technique for adsorbents preparation improved the nickel ion selectivity and adsorption capacity. We characterised the imprinted porous foam adsorbents in terms of the effects of the initial pH value, initial metal ion concentration, and contact time on the adsorption of nickel ions. The adsorption process was described best by Langmuir monolayer adsorption models, and the maximum adsorption capacity calculated from the Langmuir equation was 69.93mgg-1. The kinetic data could be fitted to a pseudo-second-order equation. Our analysis of selective adsorption demonstrated the excellent preference of the F-IIP foams for nickel ions compared with other coexisting metal ions. Furthermore, tests over five cycle runs suggested that the F-IIP foam adsorbents had good durability and efficiency.

The high flexibility and adaptability of the soft actuator have attracted wide attention. However, under the stimulation of the external environment, the complex and controllable movement of materials remain a challenge. In this work, we make a bilayer composite film simply and quickly by depositing silicone rubber (Ecoflex00-30) on the side of the plant parchment. It spontaneously controls deformation and responds sensitively in the water. This bilayer composite film exhibits a good stable actuation effect and reversibility in a humid environment or in water. We cut the strips of plant parchment into different fiber directions and control the lateral gradient in the thickness direction to achieve complex and controllable motion (bending, S-shaped, -shaped and spiral). Inspired by the plant tendrils, we design and built a soft gripper that can achieve 30 times its own weight in the water, demonstrating promising bioinspired applications.

From the perspective of waste utilization, the invasive species, Eupatorium adenophorum was used to prepare biochar, which was then loaded with iron/nickel bimetals. Compared with pure biochar, the biochar-loaded nano-iron/nickel bimetals have a significant effect on the removal of 2,4,6-trichlorophenol (2,4,6-TCP) from water, and their degradation rate can be increased by 39.7%-71.6% under different conditions. Several factors can influence the removal of 2,4,6-TCP, including the load ratio, pH of the solution, concentration of 2,4,6-TCP, and coexisting ions in water (HCO3−, SO42−, NO3−). Based on the density functional model (DET), Ni can activate H2 (produced in the reaction between nano-Fe and H2O) to convert to H*, which can then substitute Cl. The activation energy is 109.5 kJ/mol, indicating the reaction is easy to take place.

It is still a challenge to disperse yellow iron oxides in organic media due to their susceptible aggregation, which limits their application in ceramic material area. In order to achieve colloidal stabilization in organic liquid, yellow iron oxides were dispersed in ethanol with p[methyl methacrylate-r-butyl methacrylate-r-N-(3-dimethylaminopropyl) methacrylamide] random copolymers (PMBAs) based on amino groups as anchoring groups and alkyl as solvent chains by reversible-addition fragmentation chain-transfer radical (RAFT) polymerization. The effect of PMBAs on viscosity, rheological properties and dispersion stability was investigated. In the presence of PMBAs, yellow iron oxide dispersion performed excellent colloidal stability and low viscosity with high solid loadings. Furthermore, it is suggested that PMBAs have outstanding dispersion ability, retarding yellow iron oxides aggregating and keeping it stable for more than 60 days at ambient temperature. This study reveals that PMBAs might find promising application in material dispersion area.

Seven new clerodane diterpenoids, dodovisnoids A−G (1–7), were isolated from Dodonaea viscosa. The structures of these compounds were identified by extensive spectroscopic data. The absolute configurations of 1, 2, and 6 were assigned by X-ray crystallographic analysis. Compound 1 is an unprecedented clerodane diterpenoid possessing a new carbon skeleton that could biogenetically derive from 5,10-secoclerodane. Compounds 2–5 are rare cyclopropyl-modified clerodanes and 6 is the first dinor-clerodane featuring an alkynyl moiety. Compounds 4–7 showed antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro.

Self-matt coating of waterborne polyurethane (WBPU) was synthesized by combining prepolymer and self-emulsification methods. The emulsion was fabricated from both hydroxy carboxylic acid and aminosulfonic acid types of hydrophilic chain-extending agents, in which the 2-[(2-aminoethyl) amino] ethane sulphonate sodium (AAS salt) was produced in laboratory. This emulsion demonstrated an excellent matt performance without the addition of extra matting agents after filming. Four different kinds of surface properties were measured on the film: the specular gloss (60° gloss meter), the contact angle (CA), the surface roughness degree (3D Surface Profilometer), and the topography of the coatings surface (SEM). The results showed that tons of spherical particles with diameter in a few micrometers were aggregated on the film surface. The effect of the roughness parameters (R a and R q ) and the average particle size of the emulsions on the specular gloss degree were probed. The research indicated that the emulsion with average particle size in the range of 2.5–3.0 µm and, meanwhile, the film with roughness parameters R a and R q both greater than 1 µm could attain the best matt effect. The WBPU emulsions showed good physical and mechanical properties, and were introduced into wood varnish for matting purpose.

The adsorption of Ni(II) ions from aqueous solution by chitosan (CTS) and its triethylenetetramine derivative beads (CCTS) was investigated in a batch adsorption system. Chitosan beads were crosslinked with epichlorohydrin and then grafted with triethylenetetramine to obtain sorbents that are insoluble in aqueous acidic solution and improve adsorption capacity, respectively. Elemental analysis, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy were used to analyze the structure and characteristics of chitosan and its derivative. It showed that the derivative of chitosan possessed good stability in acidic solution and achieved optimal adsorption capacity at pH higher than 4.5 and the max adsorption capacity of chitosan and chitosan derivate were 58.09 and 91.44 mg/L, respectively. Their adsorption processes could be best described by the pseudo second-order model, which suggested that the rate-limiting step may be the chemical adsorption rather than the mass transport. The experimental data of adsorption of Ni 2+ by chitosan derivate was fitted well by the Langmuir isotherm model with a high correlation coefficient (R 2 > 0.99), showing that monolayer adsorption took place on the surface of chitosan derivate absorbents, while the adsorption isotherm was well fitted by Freundlich for chitosan. Furthermore, the chitosan derivate exhibited good adsorption performance after regeneration for 5 cycles. At last, FTIR and XPS analysis showed that both the nitrogen and oxygen functional groups were involved in the adsorption of Ni 2+ .