Imaging metabolic mechanisms and the binding behavior of nutrients/transporters of edible Matricaria flowers VOCs.

To promote the consumption of flowers and to utilize the nutritional value of proteins, the efficacy of the beneficial components of flowers has been intensively studied. Anthemis nobilis was used as the study object, and all its volatile components (VOCs) were fingerprinted using headspace solid-phase micro-extraction gas-mass spectrometry (HS-SPME/GC-MS). GC-MS fingerprints of five parts of Anthemis nobilis were established using three proteins, bovine lactoferrin (BLF), bovine lactoglobulin (ß-Lg), and human serum albumin (HSA), as nutrient transporters. The interactions between the volatile components from different parts of the mother chrysanthemum plant and the nutrient/transport proteins were investigated. The results of fingerprinting showed that the flavor components were dominated by alkenes. In addition, this study revealed that among the three nutrient transporters, the strongest binding to the adsorbed volatile components was HSA, followed by BLF, and ß-Lg was second. In addition, a characteristic molecule, camphene, was screened. Integrated molecular simulation using fluorescence spectroscopy was used to validate the results of the interaction of the nutrient/transport proteins systems with characteristic molecule. The properties of the characteristic molecules such as absorption, distribution, metabolism, excretion and toxicity in vivo were analyzed using ADMET to provide a theoretical basis for the preparation of flower-flavored dairy products.

Controlled synthesis of polycarbonate diols and their polylactide block copolymers using amino-bis(phenolate) chromium hydroxide complexes.

A diamine-bis(phenolate) chromium(III) complex, CrOH[L] ([L] = dimethylaminoethylamino-N,N-bis(2-methylene-4,6-tert-butylphenolate)), 2, in the presence of tetrabutylammonium hydroxide effectively copolymerizes CO2 and cyclohexene oxide (CHO) into a polycarbonate diol. The resultant low molar mass (6.3 kg mol-1) diol is used to initiate ring-opening polymerization of rac-lactide with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) giving ABA-type block copolymers with good molar mass control through varying rac-LA-to-diol loadings and with narrow dispersities. As the degree of rac-LA incorporation increases, the glass transition temperatures (Tg) are found to decrease, whereas decomposition temperatures (Td) increase. (Diphenylphosphonimido)triphenylphosphorane (Ph2P(O)NPPh3) was used as a neutral nucleophilic cocatalyst with 2, giving phosphorus-containing polycarbonates with an Mn value of 28.5 kg mol-1, a dispersity of 1.13, a Tg value of 110 °C and a Td value of over 300 °C. A related Cr(III) complex (4) having a methoxyethyl pendent group rather than a dimethylaminoethyl group was structurally characterized as a hydroxide-bridged dimer.

Development of Carbon Nanotube/Graphene-Based Alginate Interpenetrating Hydrogels for Removal of Antibiotic Pollutants.

The extensive use of pharmaceutical antibiotics in treatment of human and animal infections has resulted in growing concerns about antibiotic pollution worldwide. In this work a novel interpenetrating polymer network (IPN) hydrogel has been developed to function as an effective and non-selective adsorbent for various antibiotic pollutants in aqueous solution. This IPN hydrogel is made of multiple active components, including carbon nanotube (CNTs), graphene oxide (GO), and urea-modified sodium alginate (SA). It can be readily prepared through efficient carbodiimide-mediated amide coupling reaction followed by calcium chloride-induced alginate cross-linking. The structural properties, swellability, and thermal stability of this hydrogel have been investigated, while its adsorption properties towards an important antibiotic pollutant, tetracycline, was thoroughly characterized based on adsorption kinetic and isotherm analyses. With a BET surface area of 38.7 m2 /g, the IPN hydrogel shows an excellent adsorption capacity of 84.28±4.2 mg/g towards tetracycline in water, while the adsorption capacity is decreased by only 18 % after four cycles of use, demonstrating very good reusability. Adsorptive performance in removing two other antibiotics, neomycin and erythromycin, has also been examined and compared. Overall, our studies disclose that this newly designed hybrid hydrogel is an effective and reusable adsorbent material for treating antibiotic pollution in the environment.

Highly catalytic supramolecular host-guest complex for high value directional conversion of lignin to syringyl monomer.

In order to meet the challenge of enzyme catalysis of waste lignin, laccase (LAC)- guaiacyl(G)-type monomers noncovalent supramolecular system (LGS) were constructed for conversion of lignin. In this contribution, the catalytic effect of LGS formed by LAC and G-type monomers was studied. LAC changes the secondary structure conformation of its binding site to accommodate the G-type monomer, which is bound by hydrogen bonding and hydrophobic interactions. A mechanistic study highlights that the non-covalent complexation accelerates the internal electron transfer rate of LGS and syringol substrate for subsequent coupling reactions. In the presence of guaiacol/4-ethylguaiacol/vanillin-LAC, the conversion of dealkali lignin were 16.44, 29.12 and 22.72, respectively, higher than that in the presence of LAC alone. And the product of syringyl monomer was significantly increased in the actual lignin catalysis. Our work explains the mechanisms underlying existing enzyme-substrate interactions and enhanced catalytic system can be used for efficient utilization of waste.

Effects of polystyrene microplastics on the seed germination of herbaceous ornamental plants.

Although microplastic (MP) pollution has become an environmental issue worldwide, most related research has been confined to marine ecosystems. The impacts of MPs on terrestrial ecosystems, and especially on terrestrial plants, are poorly studied. In our study, different particle sizes (2 µm and 80 nm) and different concentrations (0, 10, 50, 100, and 500 mg·L-1) of polystyrene MPs were selected as the experimental materials, and their effects on three herbaceous ornamental plants, Trifolium repens, Orychophragmus violaceus, and Impatiens balsamina, were investigated. Seed germination tendency, germination rate, and various physiological and biochemical indicators were observed in the treated plants. The germination rates and germination potentials of these plants decreased significantly as the polystyrene MP concentration increased. Root formation, as well as a decrease in root hair density, was observed. The catalase, superoxide dismutase, hydrogen peroxide, proline, soluble protein, and soluble sugar contents all showed overall trends that increased first and then decreased, which conformed to the "Plant-ES" equation. Thus, polystyrene MPs appeared to have significant inhibitory effects on the seed germination processes of herbaceous ornamental plants.

Electrocatalytic Properties of a Novel ß-PbO2/Halloysite Nanotube Composite Electrode.

To improve the efficiency of electrochemical degradation of wastewater, lead dioxide was synthesized by a hydrothermal method with low cost, simple operation, and high conversion rate. ß-PbO2/HNT composites were prepared by a hydrothermal method with Halloysite nanotubes (HNTs) and ß-PbO2. The PbO2/HNT/ITO electrode was prepared by modifying the ß-PbO2/HNT composite on an indium tin oxide (ITO) conductive glass electrode. The morphology of the material was characterized by scanning electron microscopy and transmission electron microscopy. The electrochemical performance of the electrode was measured by cyclic voltammetry, the galvanostatic charge-discharge method, and the AC impedance method. Electrolysis of typical dye wastewater by electrochemical oxidation was carried out. The effect of electrochemical degradation of wastewater with new electrodes was investigated and the degree of electrodes falling off was compared. The solubility of electrodes was investigated by inductively coupled plasma mass spectrometry lead element analysis of wastewater. The results showed that the ß-PbO2/HNT electrodes were prepared successfully and had good charge-discharge performance and lifetime. The removal rate of electrolytic dye wastewater was 85.86%, and the degradation effect was better than that of pure PbO2 electrodes. In this work, a new type of ß-PbO2/HNT/ITO electrode has been prepared, which improved the degradation efficiency of wastewater and opened up the prospect of HNT application.

Kinetic Studies of Copolymerization of Cyclohexene Oxide with CO2 by a Diamino-bis(phenolate) Chromium(III) Complex.

A diamino-bis(phenolate) chromium(III) complex, CrCl(THF)[L], 1, where [L] = dimethylaminoethylamino- N, N-bis(2-methylene-4,6- tert-butylphenolate), has been synthesized in high yield and characterized by MALDI-TOF mass spectrometry, elemental analysis, UV-vis spectroscopy and single crystal X-ray diffraction. This complex combined with 4-dimethylaminopyridine (DMAP) or bis(triphenylphosphoranylidene)ammonium chloride or azide salts (PPNCl or PPNN3) shows improved activity over previously reported amine-bis(phenolate) chromium(III) complexes for copolymerization of cyclohexene oxide (CHO) and CO2 to yield poly(cyclohexene) carbonate (PCHC). Kinetic studies of the complex/DMAP system showed the activation energy for polycarbonate formation to be 62 kJ/mol. End group analysis of resulting polycarbonates by MALDI-TOF MS reveals either the chloride of the Cr(III) complex or the external nucleophile initiates the copolymerization reaction.

A MALDI-TOF MS analysis study of the binding of 4-(N,N-dimethylamino)pyridine to amine-bis(phenolate) chromium(III) chloride complexes: mechanistic insight into differences in catalytic activity for CO2/epoxide copolymerization.

Amine-bis(phenolato)chromium(III) chloride complexes, [LCrCl], are capable of catalyzing the copolymerization of cyclohexene oxide with carbon dioxide to give poly(cyclohexane) carbonate. When combined with 4-(N,N-dimethylamino)pyridine (DMAP) these catalyst systems yield low molecular weight polymers with moderately narrow polydispersities. The coordination chemistry of DMAP with five amine-bis(phenolato)chromium(III) chloride complexes was studied by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The amine-bis(phenolato) ligands were varied in the nature of their neutral pendant donor-group and include oxygen-containing tetrahydrofurfuryl and methoxyethyl moieties, or nitrogen-containing N,N-dimethylaminoethyl or 2-pyridyl moieties. The relative abundance of mono and bis(DMAP) adducts, as well as DMAP-free ions is compared under various DMAP : Cr complex ratios. The [LCr](+) cations show the ability to bind two DMAP molecules to form six-coordinate complex ions in all cases, except when the pendant group is N,N-dimethylaminoethyl (compound ). Even in the presence of a 4 : 1 ratio of DMAP to Cr, no ions corresponding to [L3Cr(DMAP)2](+) were observed for the complex containing the tertiary sp(3)-hybridized amino donor in the pendant arm. The difference in DMAP-binding ability of these compounds results in differences in catalytic activity for alternating copolymerization of CO2 and cyclohexene oxide. Kinetic investigations by infrared spectroscopy of compounds 2 and 3 show that polycarbonate formation by 3 is twice as fast as that of compound 2 and that no initiation time is observed.

A new phenanthroline-oxazine ligand: synthesis, coordination chemistry and atypical DNA binding interaction.

1,10-Phenanthroline-5,6-dione and l-tyrosine methyl ester react to form phenanthroline-oxazine (PDT) from which [Cu(PDT)(2)](ClO(4))(2) and [Ag(PDT)(2)]ClO(4)·2MeOH are obtained. Binding to calf-thymus DNA by Ag(I) and Cu(II) PDT complexes exceed bis-1,10-phenanthroline analogues and the minor groove binding drugs, pentamidine and netropsin. Furthermore, unlike the artificial metallonuclease, [Cu(phen)(2)](2+), the [Cu(PDT)(2)](2+) complex does not cleave DNA in the presence of added reductant indicating unique interaction with DNA.