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The inhibition mechanism of two homoisoflavonoids from Ophiopogon japonicus including methylophiopogonanone A (MO-A) and methylophiopogonanone B (MO-B) on tyrosinase (Tyr) was studied by multiple spectroscopic techniques and molecular docking. The results showed that the two homoisoflavonoids both inhibited Tyr activity via a reversible mixed-inhibition, with a half inhibitory concentration (IC50) of (10.87 ± 0.25) × 10−5 and (18.76 ± 0.14) × 10−5 mol L−1, respectively. The fluorescence quenching and secondary structure change of Tyr caused by MO-A and B are mainly driven by hydrophobic interaction and hydrogen bonding. Molecular docking analysis indicated that phenylmalandioxin in MO-A and methoxy in MO-B could coordinate with a Cu ion in the active center of Tyr, and interacted with amino acid Glu322 to form hydrogen bonding, occupying the catalytic center to block the entry of the substrate and consequently inhibit Tyr activity. This study may provide new perspectives on the inhibition mechanism of MO-A and MO-B on Tyr and serve a scientific basis for screening effective Tyr inhibitors.

The Melodinus species have been proved to be good resources of bisindole alkaloids. Six bisindole alkaloids were isolated from the leaves and stems of Melodinus cochinchinensis (Lour.) Merr. guided by HRESIMS data analysis. Among them, melokhanines K-M, epi-scandomelonine, and epi-scandomeline possessed aspidosperma-scandine skeleton linked by a C–C bond while meloyine II had a scandine-scandine skeleton. The structures were established by extensive spectroscopic analysis of their HRESIMS and NMR data. Melokhanines K-M were undescribed compounds, while epi-scandomelonine, epi-scandomeline and meloyine II were known compounds, which were reported from Melodinus species for the first time. The anti-inflammatory and cytotoxic activities of the isolates were also evaluated in vitro. Melokhanine K and meloyine II showed potent inhibitory activity on the production of nitric oxide, interleukin-6, and tumor necrosis factor-α in LPS-induced RAW 264.7 macrophages, whereas epi-scandomelonine and epi-scandomeline exhibited certain cytotoxic activity against MOLT-4 cells with IC50 values 5.2 and 1.5 μM, respectively.

Phytochemical investigation on the aerial parts of Trachelospermum dunnii led to the isolation and identification of 16 compounds, including nine dibenzylbutyrolactone lignans ( 1 – 9 ), two furanoid lignans ( 10 – 11 ), one dihydrobenzofuran lignan ( 12 ), one aryltetralin lignan ( 13 ), two flavonoids ( 14 – 15 ), and one phenolic compound ( 16 ). The structure of compound 1 was elucidated by means of spectroscopic analyses, including HRESIMS, and 1D and 2D NMR experiments. Compounds 1–16 are reported from title plant for the first time, while compounds 1 – 2 , 10 – 12 , and 14 – 16 have not been recorded previously in genus Trachelospermum . The dibenzylbutyrolactone lignans may serve as chemotaxonomic markers of T. dunnii .

Methylophiopogonanone B (MO-B), which belongs to a group of homoisoflavonoids, present in Ophiopogon japonicus, has been identified as an active component with antioxidative and anti-tumor properties. The present study investigated whether MO-B may exert protective effects on human umbilical vein endothelial cells (HUVECs) against H2O2-induced injury in vitro, and whether the MO-B effects may be modulated by the NADPH pathway. HUVECs were treated with MO-B in the presence or absence of H2O2. Malondialdehyde (MDA), reactive oxygen species (ROS) levels, and superoxide dismutase (SOD) activity were analyzed to evaluate cell injury and the antioxidative potential of MO-B. The results revealed that MO-B inhibited the production of MDA and ROS, but enhanced SOD activity. Furthermore, MO-B could alleviate H2O2-induced apoptosis in HUVECs, which is consistent with the expression of apoptosis-associated genes and proteins in cells, including Bax/Bcl-2 and caspase-3. To explore the potential mechanism, the present study investigated the effects of MO-B on NADPH-related signaling via the analysis of neutrophil cytochrome b light chain (p22phox) expression, which is the membrane-associated subunit of NADPH oxidase. MO-B could improve the survival of endothelial cells and therefore may be a potential drug in the treatment of cardiovascular diseases.

We demonstrated a high-performance Si-organic hybrid heterojunction solar cell utilizing low-temperature and liquid-phase-processed TiO2 as an interlayer between poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and Si nanoholes to produce a conformal contact on the surface of the Si nanostructure. The hydrophilic TiO2/Si-nanohole surface enabled the PEDOT:PSS to flow into the spacing of the close-packed nanoholes. Scanning electron microscopy images were used to confirm the PEDOT:PSS nanohole filling induced by the TiO2. With forming gas annealing of the double-sided TiO2, high Voc (0.63 V) and Jsc (35.7 mA/cm2) values were obtained, yielding a high power conversion efficiency of 14.7%. The high Voc was attributed to the surface passivation of Si by annealed TiO2. The X-ray photoelectron spectroscopy investigation at the TiO2/Si interface indicates the TiOx signal decreased and the TiO2 and SiOx signals increased after annealing. The Si–O bonding found in the O 1s study appeared in the...

Melodinus cochinchinensis (Lour.) Merr. has been used in Traditional Chinese Medicine for the management of various ailments, yet its chemical constituents are rarely studied. This study was aimed to isolate terpenoid indole alkaloids (TIAs) from the aerial parts of M. cochinchinensis by the guidance of ultrahigh-performance liquid chromatography coupled with a tandem mass spectrometry (UHPLC-MS/MS), and to elucidate their cytotoxic, immunosuppressive and anti-inflammatory activities. Eight new TIAs (1 and 5-11) along with 21 previously described analogues were isolated with the basis of molecular networking developed by our previously reported TIAs from the species of Melodinus. The structures of new TIAs were elucidated by the analysis of extensive spectroscopic data. Among the tested isolates, 11-methoxytabersonine (25) exhibited considerable cytotoxic activity against human acute lymphoblastic leukemia (MOLT-4), breast adenocarcinoma (MCF-7), pro-myeloid leukemia (HL-60), lung adenocarcinoma (A-549), and hepatocelluar carcinoma (SMMC-7721) cell lines, which was more effective than the positive control, cisplatin. The 19β-hydroxyvenalstonidine (21) displayed moderate immunosuppressive effect against Con A-induced splenocyte proliferation at 40 μM, while 16,17-dehydro-19S-vindolinine (1) showed potent inhibitory activity on nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) expressions in LPS-induced RAW 264.7 macrophages.

Bandgap enlarged Mg-doped aluminum zinc oxide (Mg-doped AZO) film is a potential transparent conducting oxide for applications in photonics devices. The oxide film normally deposited by sputtering, particularly using ceramic targets, while maintaining its pristine property for the film deposited using metallic targets is rarely addressed. This study investigated the optical and electrical properties of Mg-doped AZO films that were performed by a magnetron reactive co-sputtering method using metallic Mg and Al&ndash, Zn targets. Doping of Mg in the AZO significantly affects the electrical resistivity and optical transmission of the films because Mg tends to replace part of Zn lattice sites. The 1.2 at.% Mg-doped AZO film had an electrical resistivity of 7.9 &times, 10&minus, 4 &Omega, &middot, cm, an optical transmittance of 92.6% in the visible light range, and a bandgap of 3.66 eV when the film was post-annealed at 600 &deg, C. The Mg doping widens the bandgap and, thus, increases the transmittance of the AZO film. Because of the superior electrical and optical characteristics, the Mg-doped AZO films prepared using the metallic targets can be a reliable transparent conducting oxide for applications.

The structures of pestalrones A-B were revised via reinterpretation of the NMR data and a brief chemical transformation from the co-occurring polyketides, in our investigation on the secondary metabolites of Pestalotiopsis zonata, which also afforded a new α-pyrone derivative, pestazonatic acid, and four known analogs.

The overlying free film method was used to study the nanoTiO2 and UV absorbing agent modified water-borne acrylic varnish and polyurethane varnish of dyed veneer photochromic suppression effectiveness, using infrared spectrum analyzed the photochromic behavior of dyed veneer under different coated condition. Results showed that dyed veneer covered with UV modification film has the best light restraint, film modified by nanoTiO2 takes second place, and unmodified film worst. Photochromic inhibitory rate of UV modified polyurethane and acrylic paint film were 56.37% and 33.59% respectively, the rate of nanoTiO2 was 15.85% and 17.24%.

Wood plastic composite (WPC) in this study was made from high density polyethylene (DHPE) or low density polyethylene (LDPE) with different species wood flour using extrusion. Ethylene vinyl acetate (EVA) was used to improve the weathering resistance performance of WPC. Degradation test and ageing test were employed to study the weathering stability of WPC modified by EVA. The results show that EVA can improve the ageing resistant performance of WPC and have no significant effect on the degradation resistant performance of WPC. It suggests that EVA can be used to improve the weathering resistance performance of WPC.

The objective of this study was to investigate the effects of microbial transglutaminase (MTGase) on the rheological and textural characteristics of black soybean packed tofu containing agar as the coagulant. Results showed that the addition of MTGase increased the gelation temperature of soymilk, and produced a firmer and more elastic packed tofu with low cooking loss. Dynamic rheological and textural parameters of the tofu were significantly affected by enzyme concentration, incubation temperature and time. Both G′ and η∗ were positively correlated to the hardness, gumminess and adhesiveness of packed tofu, thus the rheological parameters (G′ and η∗) were good indicators of the texture of the packed tofu. Results suggested that good quality packed tofu could be produced by mixing 90 g black soymilk solid and 2 g agar powder in 1 L of water and incubating with 10 g MTGase for 30 min at 55 °C.

A new class of platinum(II) acetylide complexes with urea group, [Pt(tBu3tpy)(CCC6H4-4-NHC(O)NHC6H4-4-R)](OTf) (tBu3tpy = 4,4′,4′′-tri-tert-butyl-2,2′:6′,2′′-terpyridine; R = H (3a), Cl (3b), CF3 (3c), and NO2 (3d)), has been synthesized and characterized. The crystal structures of 3a, 3a·DMF·THF, 3b·CH3CN, and 3c·CH3CN have been determined by X-ray diffraction. Upon excitation at λ > 380 nm, the solid samples of complexes 3a–3d show orange light at 298 K. The anion binding properties of complexes 3a–3d have been studied by UV-vis titration experiments in CH3CN and DMSO. In general, the log K values of 3a–3d with the same anion in CH3CN depend on the substituent R on the acetylide ligand of 3a–3d and follow this order: R = NO2 (3d) > CF3 (3c) > Cl (3b) > H (3a). For the same complex with different anions, the log K values are in the following order: F− > OAc− > Cl− > Br− ≈ HSO4− ≈ NO3− > I−, which is in accordance with the decrease in the basicity of anions. Complex 3d with NO2 group shows a dramatic colour change towards F− in DMSO, allowing the naked eye detection of F−.

This experiment is to research the chemical compositions of the crosslink of the woolen, oxidized with H2O2 of various concentrations and temperatures, cured with the citric acid and TiO2/chitosan liquid of different proportions, and then observed by means of Fourier Trans- fer Infrared Spectrometer (FT-IR), Scanning Electronic Mi- croscope (SEM), Energy Dispersive Spectrometer (EDS), and Thermo-Gravity Analyzer (TGA). Its antishrinkage, antimi- crobes, antiultraviolet, strength, elasticity, softness, and yel- lowness are also investigated to study the changes in its physical properties. From the result, we can see, under the SEM, the sign of disappearance of woolen scales owing to the destruction by H2O2 oxidization; the more H2O2 and its oxidization temperature, the more serious their destruction. The phenomenon of crosslink is not obvious after oxidiza- tion and curing treatment with TiO2/chitosan, but it some- how apparently happens to the woolen surface. Because TiO2/chitosan does not intertwine with the woolen well, which has few effects of heat, the woolen shrinks less with more H2O2 and oxidization temperatures. Its antishrinkage is better. But the more wash, the more shrinkage. However, TiO2 covered with chitosan catches less sunlight, and thus cannot suppress or even kill microbes. The woolen pro- cessed with nanometer TiO2 enhances the effect of antiul- traviolet, which is better as the density of TiO2 increases. The strength and elasticity of the woolen are worse for more H2O2 and the higher temperature destroy scales and make the woolen coarse, yellow,and less soft. © 2006 Wiley Period

Background Some phthalic acid esters (PAEs) and nonylphenol (NP) are endocrine-disrupting chemicals (EDCs) that are widely used in consumer products. Consequently, the general population is exposed simultaneously to both groups of chemicals. Objective To investigate the single- and co-exposure effects of PAEs (DMP, DEP, DnBP, DiBP, BBzP, and DEHP) and NP on obesity and pubertal maturity to compare the body sizes of general adolescents with the complainants of the phthalate-tainted foods scandal that occurred in Taiwan. Methods This study included 270 general adolescents aged 6.5–15.0 years and 38 complainants aged 6.5–8.5 years. Nine metabolites of the five PAEs and of NP were measured in urine. We used a questionnaire to evaluate pubertal maturity, measured anthropometric indices (APs) to assess body size, and collected urine samples to measure the two groups of chemicals. Results We found that urinary PAE metabolite concentrations (specifically, metabolites of DEP, DnBP, DiBP, and DEHP) were positively associated with the APs for abdominal obesity (including skinfold thickness, waist circumference, waist-to-height ratio, and waist-to-hip) and indicated a dose–response relationship. Mono-methyl phthalate (MMP) exposure was inversely associated with pubarche among boys. The daily intake of DEHP in general adolescents exceeded the reference doses (RfD-20 μg/kg bw/day) and tolerable daily intake (TDI-50 μg/kg bw/day) by 3.4% and 0.4%, respectively. No associations were observed between NP exposure or co-exposure and the APs or pubertal maturity. No significant differences were observed between general adolescents and the complainants with regard to weight, height, or BMI. Conclusions The study suggests that PAE (specifically, DEP, DnBP, DiBP, and DEHP) exposure is associated with abdominal obesity in adolescents and that the APs for abdominal obesity are more sensitive than BMI for measuring obesity among adolescents. We suggest that the RfD and TDI for PAEs should be revised to provide sufficient protection.

Monte Carlo and molecular dynamics simulations of interlayer molecular structure in the one-, two-, and (hypothetical) three-layer hydrates of K-montmorillonite were performed concurrently in order to elucidate counterion speciation and water structure in the electrical double layer of this clay mineral. Calculated layer spacings, interlayer water potential energies, and counterion mobilities were in agreement with available experimental data. In the one-layer hydrate, both outer-sphere and inner-sphere surface complexes of K+ were observed, the latter always near sites of tetrahedral charge substitution, with the counterion species exchanging readily on the simulation time scale (up to 200 ps). In the two- and three-layer hydrates, the surface complexes persisted, but an incipient diffuse layer of counterions also was observed, with all three types of surface species engaging in sluggish exchange. Water molecules in the one-layer hydrate resided at the interlayer midplane, whereas in the two-layer hydrat...

Molecular structure in the interlayers of lithium-Wyoming montmorillonite with one, two, or three adsorbed water layers was investigated for the first time by concurrent Monte Carlo and molecular dynamics simulation, based on the MCY model of water−water interactions. Calculated layer spacings, as well as interlayer-species self-diffusion coefficients, were in good agreement with available experimental data. Inner-sphere surface complexes of Li+ with tetrahedral charge sites were observed in all hydrates, whereas outer-sphere surface complexes of Li+ with octahedral charge sites, found in the one-layer hydrate, dissociated from the clay mineral basal planes into a diffuse layer in the two- and three-layer hydrates, a signature of the strong interaction between Li+ and water molecules. Interlayer water molecules tended to solvate Li+, although some were entrapped within cavities in the montmorillonite surface. All of the adsorbed Li+ and interlayer water species exchanged on the time scale (0.2 ns) of the ...

The purpose of present study was to investigate, using a disk model, the effects of charge density and 1–1 electrolyte properties on the diffuse portion of the electrical double layer near a 2:1 clay mineral particle. Numerical solutions for the inner potential and anion exclusion volume were obtained by solving a Poisson–Boltzmann equation with varying parameter values for electrolyte ion radius, electrolyte concentration, basal plane charge density, and edge surface charge density. Although the negative electrostatic potential of the basal planes may spill over to dominate a positively charged edge surface at low electrolyte concentrations because of the typically large particle radius-to-thickness ratio, the simulation results suggested that the spillover effect diminishes with an increase in 1–1 electrolyte concentration. The electric potential surrounding the edge surface is more positive for large (0.4 nm) hard-sphere electrolyte ions than for small (0.2 nm) or point-charge ions. Reducing the basal plane charge density does not significantly affect the anion exclusion volume over a wide range of electrolyte concentration. A highly positive edge surface, however, may spill over to dominate the basal plane and thereby adsorb significant amounts of anions at low electrolyte concentrations. The disk model predictions of anion adsorption or exclusion behavior for 2:1 clay mineral particles were consistent with available experimental observations.

Molecular structure in the interlayers of sodium Wyoming montmorillonite with one, two, or three water monolayers was investigated by Monte Carlo and molecular dynamics simulation, based on tested water-water, water-counterion, clay-water, and clay-counterion potential unctions. Calculated layer spacings and thermodynamic properties, as well as interlayer water configurations and interlayer-species self-diffusion coefficients, were in good agreement with available experimental data. Inner-sphere surface complexes of Na+ with tetrahedral charge sites persisted in all hydrates, whereas the outer-sphere surface complexes with octahedral charge sites found in the one-layer hydrate dissociated partially into an incipient diffuse layer in the two- and three-layer hydrates. Even in the three-layer hydrate, interlayer water molecules did not replicate their structure or mobility in bulk aqueous solution. Improved diffraction and spectroscopic data on interlayer water are needed to guide future simulation studies.

Monte Carlo (MC) simulations of interlayer molecular structure in monolayer hydrates of Na- saturated Wyoming-type montmorillonites and vermiculite were performed. Detailed comparison of the stimulation results with experimental diffraction and thermodynamic data for these clay-water systems indicated good semiquantitative to quantitative agreement. The MC simulations revealed that, in the monolayer hydrate, interlayer water molecules tend to increase their occupation of the midplane as layer charge increases. As the percentage of tetrahedral layer charge increases, water molecules are induced to interact with the siloxane surface O atoms through hydrogen bonding and Na § counter-ions are induced to form inner-sphere surface complexes. These results suggest the need for careful diffraction experiments on a series of monolayer hydrates of montmorillonite whose layer charge and tetrahedral isomorphic substitution charge vary systematically.

Monte Carlo (MC) simulations of molecular structure in the interlayers of 2:1 Na-saturated clay minerals were performed to address several important simulation methodological issues. Investigation was focused on monolayer hydrates of the clay minerals because these systems provide a severe test of the quality and sensitivity of MC interlayer simulations. Comparisons were made between two leading models of the water-water interaction in condensed phases, and the sensitivity of the simulations to the size or shape of the periodically-repeated simulation cell was determined. The results indicated that model potential functions permitting significant deviations from the molecular environment in bulk liquid water are superior to those calibrated to mimic the bulk water structure closely. Increasing the simulation cell size or altering its shape from a rectangular 21.12 A × 18.28 A × 6.54 A cell (about eight clay mineral unit cells) had no significant effect on the calculated interlayer properties.

The purpose of the present study is to investigate theoretically, by using a disk model, the effect of finite particle size on the electrical double layer of a 2:1 clay mineral particle suspended in a 1-1 electrolyte solution. The clay mineral particle is represented as a thin disk with negatively charged basal planes and a positively charged edge surface. We applied modified Gouy-Chapman theory to the disk model and solved the Poisson-Boltzmann equation numerically using a self-adaptive finite-element method. To carry out the computer simulation, tree and linked-list structures, nested dissection node ordering, and dynamic memory allocation techniques were implemented in the program DISKMGCT. We found an adsorption barrier at an electrolyte concentration of 0.1 mol m-3 for anions approaching the edge surface. This adsorption barrier, originating from a negative inner potential near the edge surface, is mainly controlled by particle thickness. The anion exclusion volume is also determined by the individual values of particle thickness and radius. For a particle of very small radius (⩽10 nm), the anion exclusion volume as calculated from the disk model was significantly larger than that obtained from the conventional infinite-plane Gouy-Chapman theory in dilute electrolyte solutions. For a particle of thickness ⩾4.9 nm, the anion exclusion volume does not decrease monotonically, but instead changes from negative to positive values with an increase in electrolyte concentration. Differences between the predictions of the disk and the infinite-plane models decrease with increasing electrolyte concentration. Thus, the presence of a positively charged edge surface affects clay-electrolyte interactions most significantly at low electrolyte concentrations.

Paclitaxel (PTX) is usual for the treatment of a variety of malignancies, however, its applications are greatly limited due to its poor water solubility. Over the past years, there has been a considerable research interest in the area of nanoscale drug delivery systems (DDSs) as carrier for PTX due to their solubilization, safety, targeting and controlled release. There are many different types and shapes of nanoscale DDSs that have been prepared to deliver PTX, including nanoliposome, lipid nanoemulsion, nanosuspension, nanocapsule, nanofiber, nanotube, nanopolymersome, micelle and nanoparticle (NP). Nanoscale DDSs can be based on lipids, proteins, polysaccharides, polymers or other materials. The recent strategic developments of PTX formulation have been discussed with emphasis on lipid-, polymer- and protein-based nanoscale DDSs. Here we focus on the comparative analysis of the preparation, morphology, solubilization, targeting, penetrability, controllability and efficacy profile of various PTX-loaded nanoscale DDSs, which were reported in the different researches. Meanwhile the advantages and disadvantages are also discussed for each type of DDS. Furthermore, the current review embodies an in-depth discussion of human serum albumin (HSA) NP formulation, which showed significantly great efficacy and low toxicity. All the information obtained in this review might shed light on designing new and better nanoscale PTX formulations for potential anticancer applications in the clinic.

In order to shorten processing time for large grain polycrystalline Si thin films prepared by aluminum induced crystallization, the stack of a-Si/SiO2/Al is deposited by radio frequency magnetron sputtering and annealed at two different irregular temperature profiles. The influence of irregular temperature profile on the processing of amorphous silicon prepared by the aluminum induced crystallization is investigated and the condition is discussed under which whether new nucleation appears when the annealing temperature increases. It turns out that the formation of nucleation is governed by the relationship among the grain radium at low temperature, the distance of depletion region, and the distance of adjacent grains.