The polyphenolic profiles and antioxidant effects of Agastache rugosa Kuntze (Banga) flower,leaf, stem and root

Agastache rugosa Kuntze (Korean mint) is used as a spice and in folk medicine in East Asia. The present study identified a total of 18 polyphenols from the flower, leaf, stem and roots of this plant using high‐performance liquid chromatography–tandem mass spectrometry. Fourteen of these compounds had not previously been identified in these plant tissues. Each polyphenol was validated in comparison with external calibration curves constructed using structurally related compounds, with determination coefficients >0.9993. The limits of detection and quantification were 0.092–0.650 and 0.307–2.167 mg/L, respectively. Recoveries of 61.92–116.44% were observed at two spiking levels, with 0.91–11% precision, expressed as relative standard deviation (except anthraquinone spiked at 10 mg/L). Hydroxycinnamic acid was the most abundant compound in the root, while the flowers showed the highest total flavonoid level. Antioxidant activities, determined in terms of reducing power, Fe²⁺ chelating activity and the radical scavenging activities using α,α‐diphenyl‐β‐picrylhydrazyl and 2‐2?‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid, increased in a concentration‐dependent manner; the highest activity was identified in the stems, followed by leaves > flowers > roots. These findings indicate that A. rugosa is a good source of bioactive compounds and can be used as a functional food. Copyright © 2015 John Wiley & Sons, Ltd.     

Residual determination and risk assessment of buprofezin in plum (Prunus domestica) grown in open‐field conditions following the application of three different formulations

This study was conducted to characterize the residual level and perform a risk assessment on buprofezin formulated as an emulsifiable concentrate, wettable powder, and suspension concentrate over various treatment schedules in plum (Prunus domestica). The samples were extracted with an AOAC quick, easy, cheap, effective, rugged, and safe, ‘QuEChERS’, method after major modifications. As intrinsic interferences were observed in blank plum samples following dispersive‐solid phase extraction (consisting of primary secondary amine and C₁₈ sorbents), amino cartridges were used for solid‐phase extraction. Analysis was carried out using liquid chromatography with diode array detection and confirmed by liquid chromatography–tandem mass spectrometry. The method showed excellent linearity with determination coefficient (R² = 1) and satisfactory recoveries (at two spiking levels, 0.5 and 2.5 mg/kg) between 90.98 and 94.74% with relative standard deviation (RSD) ≤8%. The limit of quantification (0.05 mg/kg) was considerably lower than the maximum residue limit (2 mg/kg) set by the Codex Alimentarius. Absolute residue levels for emulsifiable concentrates were highest, perhaps owing to the dilution rate and adjuvant. Notably, all formulation residues were lower than the maximum residue limit, and safety data proved that the fruits are safe for consumers. Copyright © 2016 John Wiley & Sons, Ltd.     

Volatile organic compounds of Angelica gigas Nakai, Korean medicinal herb

The study was performed to find out the profile of volatile flavor components from the aromatic medicinal plant, Angelica gigas Nakai. The volatile organic compounds of A. gigas Nakai were extracted by simultaneous steam distillation and extraction (SDE) method, and identified by gas chromatograph/mass spectrometric (GC/MS) analysis. A total of 116 compounds, including 40 hydrocarbons, 37 alcohols, 15 esters, 12 aldehydes, 7 ketones, and 5 miscellaneous were identified and quantified. Among them, 75 volatile organic compounds were detected which make up 90.52% of total volatile content. alpha-Pinene was detected as the prime volatile component which accounted for 30.89% of total volatile content and 2,4,6-trimethyl heptane, camphene, alpha-limonene, beta-eudesmol, vervenol, alpha-murrolene, and sphatulenol were detected as the major components of A. gigas Nakai.     

Application of pressurized fluid extraction technique in the gas chromatography-mass spectrometry determination of sterols from marine sediment samples

In order to determine steroid compounds in GC/MS an analytical method using pressurized fluid extraction (PFE) was developed. While extracting in-house reference material (coastal sediment) typical recovery in PFE ranged from 80 to 120% (+/-2.5-14.5) and the average extraction yield in PFE in comparison to conventional soxhlet extraction was 115%. In particular, the PFE showed higher extraction efficiency for C29 and dien sterols. Optimizing parameters such as temperature and pressure is critical in achieving this efficiency. Sterols in the sediment were derivatized with silyl reagent BSTFA in acetone for the final determination. A short column florisil cleanup offered the best separation of the GC/MS sensitive derivatives from co-contaminants. Thirty-three coastal sediment samples were analyzed using PFE and Soxhlet extraction methods. The results on extraction efficiency, silyl derivatization kinetics and purification efficiency demonstrated that PFE is far superior in extracting sterols from sediment samples. It is simple, fast, efficient and amenable for automation.     

Xanthine Sensors Based on Anodic and Cathodic Detection of Enzymatically Generated Hydrogen Peroxide

A xanthine biosensor was fabricated by the covalent immobilization of xanthine oxidase (XO) onto a functionalized conducting polymer (Poly‐5, 2′: 5′, 2″‐terthiophine‐3‐carboxylic acid), poly‐TTCA through the formation of amide bond between carboxylic acid groups of poly‐TTCA and amine groups of enzyme. The immobilization of XO onto the conducting polymer (XO/poly‐TTCA) was characterized using cyclic voltammetry, quartz crystal microbalance (QCM), and X‐ray photoelectron spectroscopy (XPS) techniques. The direct electron transfer of the immobilized XO at poly‐TTCA was found to be quasireversible and the electron transfer rate constant was determined to be 0.73 s^?1. The biosensor efficiently detected xanthine through oxidation at +0.35 V and reduction at ?0.25 V (versus Ag/AgCl) of enzymatically generated hydrogen peroxide. Various experimental parameters, such as pH, temperature, and applied potential were optimized. The linear dynamic ranges of anodic and cathodic detections of xanthine were between 5.0×10^?6?1.0×10^?4 M and 5.0×10^?7 to 1.0×10^?4 M, respectively. The detection limits were determined to be of 1.0×10^?6 M and 9.0×10^?8 M with anodic and cathodic processes, respectively. The applicability of the biosensor was tested by detecting xanthine in blood serum and urine real samples.     

Pt‐Nanoparticle Incorporated Carbon Paste Electrode for the Determination of Cu(II) Ion by Anodic Stripping Voltammetry

Pt‐nanoparticles were synthesized and introduced into a carbon paste electrode (CPE), and the resulting modified electrode was applied to the anodic stripping voltammetry of copper(II) ions. The synthesized Pt‐nanoparticles were characterized by cyclic voltammetry, scanning electron microscopy and X‐ray photoelectron spectroscopy techniques to confirm the purity and the size of the prepared Pt‐nanoparticles (ca. 20 nm). This incorporated material seems to act as catalysts with preconcentration sites for copper(II) species that enhances the sensitivity of Cu(II) ions to Cu(I) species at a deposition potential of ?0.6 V in an aqueous solution. The experimental conditions, such as, the electrode composition, pH of the solution, pre‐concentration time, were optimized for the determination of Cu(II) ion using as‐prepared electrode. The sensitivity changes on the different binder materials and the presence of surfactants in the test solution. The interference effect of the coexisted metals were also investigated. In the presence of surfactants, especially TritonX‐100, the Cu(II) detection limit was lowered to 3.9×10^?9 M. However, the Pt‐nanoparticle modified CPE begins to degrade when the period of deposition exceeds to 10 min. Linear response for copper(II) was found in the concentration range between 3.9×10^?8 M and 1.6×10^?6 M, with an estimated detection limit of 1.6×10^?8 M (1.0 ppb) and relative standard deviation was 4.2% (n=5).     

A rhodium‐catalyzed route for oxidative coupling and cyclization of 2‐aminobenzyl alcohol with ketones leading to quinolines

2‐Aminobenzyl alcohol undergoes oxidative cyclization with aryl(alkyl), alkyl(alkyl) and cyclic ketones in dioxane at 80° in the presence of a catalytic amount of RhCl(PPh₃)₃ along with KOH to afford the corresponding quinolines in good yields. The catalytic pathway seems to be proceeded via a sequence involving initial oxidation of 2‐aminobenzyl alcohol to 2‐aminobenzaldehyde by a rhodium catalyst, cross aldol reaction between 2‐aminobenzaldehyde and ketones, and cyclodehydration.     

All electron ab initio investigations of the electronic states of the MoN molecule

The low lying electronic states of the molecule MoN were investigated by performing all electron ab initio multi-configuration self-consistent-field (CASSCF) calculations. The relativistic corrections for the one electron Darwin contact term and the relativistic mass-velocity correction were determined in perturbation calculations. The electronic ground state is confirmed as being ⁴∑⁻. The chemical bond of MoN has a triple bond character because of the approximately fully occupied delocalized bonding π and σ orbitals. The spectroscopic constants for the ground state and ten excited states were derived. The excited doublet states ²∑⁻, ²Γ, ²Δ, and ²∑⁺ are found to be lower lying than the ⁴Π state that was investigated experimentally. Elaborate multi-configuration configuration-interaction (MRCI) calculations were carried out for the states ⁴∑⁻ and ⁴∏ using various basis sets. The spectroscopic constants for the ⁴∑⁻ ground state were determined as r_e=1.636 Å and ω_e=1109 cm⁻¹, and for the ⁴∏ state as r_e=1.662 Å and ω_e=941 cm⁻¹. The values for the ground state are in excellent agreement with available experimental data. The MoN molecule is polar with a charge transfer from Mo to N. The dipole moment was determined as 2.11 D in the ⁴∑⁻ state and as 4.60 D in the ⁴∏ state. These values agree well with the revised experimental values determined from molecular Stark spectroscopic measurements. The dissociation energy, D_e, is determined as 5.17 eV, and D₀ as 5.10 eV.     

Water Extract of Fritillariae thunbergii Bulbus Inhibits RANKL-Mediated Osteoclastogenesis and Ovariectomy-Induced Trabecular Bone Loss

Fritillariae thunbergii bulbus has been widely used to treat symptoms of coughs and airway congestion in the chest due to pathological colds and damp phlegm in traditional Chinese medicine. Despite its long history of traditional use, its pharmacological activities on osteoclastogenesis and osteoporosis have not been evaluated. This study investigated the effects of the water extract of Fritillariae thunbergii bulbus (WEFT) on osteoclast differentiation in bone marrow-derived macrophage cells and on ovariectomy (OVX)-induced osteoporosis in mice. We found that WEFT significantly inhibited osteoclastogenesis by downregulating the receptor activator of the NF-κB ligand (RANKL) signaling-induced nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) expression. In an OVX-induced osteoporosis model, WEFT significantly prevented the OVX-induced trabecular loss of femurs, accompanied by a reduction in fat accumulation in the bone marrow and liver. In addition, WEFT significantly prevented weight gain and gonadal fat gain without recovering uterine atrophy. Using ultrahigh-performance liquid chromatography-tandem mass spectrometry, seven alkaloids (peimisine glucoside, yibeissine, peiminoside, sipeimine-glucoside, peimisine, peimine, and peiminine) were identified in WEFT. The results of this study suggest that WEFT can be a potential pharmacological candidate to reduce menopausal osteoporosis and menopause-related symptoms, such as fat accumulation.     

Thickness dependence of thermally induced changes in surface and bulk properties of Nafion® nanofilms

Thermally induced changes in surface wettability, dewetting behavior, and proton transport of “self‐assembled” nanothin Nafion^® films (4–300 nm) on SiO₂ substrate is reported. Thermal annealing induces switching of the surface wettability of 55 nm and thinner films from hydrophilic to super‐hydrophobic. Thickness dependence of this behavior is observed with higher annealing temperature required for lower thickness films, indicating highly restrictive mobility of Nafion^® ionomer as film thickness decreases. Dewetting is only observed for 4‐nm thin film. Significant suppression in proton conductivity upon thermal annealing was noted. Similarly, two other bulk properties, water uptake and swelling, were found to decrease upon annealing. This work reports a systematic examination of the thickness dependence of thermally induced changes in both surface and bulk properties of ultra‐thin Nafion^®. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1267–1277