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In this study, we develop a novel urchin-like Co nanomatrix precursor that allows for precise control of the Sm/Pr ratio in the composite material, resulting in the successful synthesis of SmxPr1–xCo5 particles with tunable magnetic properties and strong anisotropy. Our analysis, including transmission electron microscopy and elemental mapping, confirmed the creation of single-crystal SmxPr1–xCo5 particles with controllable composition and desired properties. Notably, the Sm0.5Pr0.5Co5 particles demonstrated significant magnetocrystalline anisotropy and exceptional magnetic properties, including a high (BH)max of 16.1 MGOe and a high Hcj of 13.4 kOe. This innovative method may advance facile access to the chemical synthesis of multicomponent rare earth magnetic particles with adjustable properties to meet different application requirements. [ABSTRACT FROM AUTHOR]

Background: Two important flavonoids, kaempferol and quercetin possess remarkably potent biological impacts on human health. However, their structural complexity and low abundance in nature make both bulk chemical synthesis and extraction from native plants difficult. Therefore microbial production via heterologous expression of plant enzymes can be a safe and sustainable route for their production. Despite several attempts reported in microbial hosts, the production levels of kaempferol and quercetin still stay far behind compared to many other microbial-produced flavonoids. Results: In this study, Saccharomyces cerevisiae was engineered for high production of kaempferol and quercetin in minimal media from glucose. First, the kaempferol biosynthetic pathway was reconstructed via screening various F3H and FLS enzymes. In addition, we demonstrated that amplification of the rate-limiting enzyme AtFLS could reduce the dihydrokaempferol accumulation and improve kaempferol production. Increasing the availability of precursor malonyl-CoA further improved the production of kaempferol and quercetin. Furthermore, the highest amount of 956 mg L− 1 of kaempferol and 930 mg L− 1 of quercetin in yeast was reached in fed-batch fermentations. Conclusions: De novo biosynthesis of kaempferol and quercetin in yeast was improved through increasing the upstream naringenin biosynthesis and debugging the flux-limiting enzymes together with fed-batch fermentations, up to gram per liter level. Our work provides a promising platform for sustainable and scalable production of kaempferol, quercetin and compounds derived thereof. [ABSTRACT FROM AUTHOR]

Isoflavonoids comprise a class of plant natural products with great nutraceutical, pharmaceutical and agricultural significance. Their low abundance in nature and structural complexity however hampers access to these phytochemicals through traditional crop-based manufacturing or chemical synthesis. Microbial bioproduction therefore represents an attractive alternative. Here, we engineer the metabolism of Saccharomyces cerevisiae to become a platform for efficient production of daidzein, a core chemical scaffold for isoflavonoid biosynthesis, and demonstrate its application towards producing bioactive glucosides from glucose, following the screening-reconstruction-application engineering framework. First, we rebuild daidzein biosynthesis in yeast and its production is then improved by 94-fold through screening biosynthetic enzymes, identifying rate-limiting steps, implementing dynamic control, engineering substrate trafficking and fine-tuning competing metabolic processes. The optimized strain produces up to 85.4 mg L−1 of daidzein and introducing plant glycosyltransferases in this strain results in production of bioactive puerarin (72.8 mg L−1) and daidzin (73.2 mg L−1). Our work provides a promising step towards developing synthetic yeast cell factories for de novo biosynthesis of value-added isoflavonoids and the multi-phased framework may be extended to engineer pathways of complex natural products in other microbial hosts. Isoflavonoids are a class of industrially important plant natural products, but their low abundance and structural complexity limits their availability. Here, the authors engineer Saccharomyces cerevisiae metabolism to become a platform for efficient production of daidzein which is core chemical scaffold for isoflavonoid biosynthesis, and show its application for production of bioactive glucosides from glucose. [ABSTRACT FROM AUTHOR]

One of the most significant challenges in boron neutron capture therapy (BNCT) is to have an ideal boron delivery agent which can deliver sufficient numbers of boron atoms to designated tumor cells. In this work, mild synthetic conditions for synthesis of dipeptidyl multiple boron-containing analogs under microwave-assisted condition were investigated. The results showed that the reaction generally took place at 50 °C, but higher reaction temperature was required when a fluorinated building block was used. The resulting peptidyl skeletons generated by Ugi four-component reaction resemble basic cell metabolites and could potentially be used as alternative replacements for current boron carrier agents in BNCT. [ABSTRACT FROM AUTHOR]

ABSTRACT Two new electron-transporting copolyphenylenes P1NH and P2NH possessing balanced charges crucial to emission efficiency of polymer light-emitting diodes (PLEDs) have been synthesized and applied as an electron-transporting layer (ETL). The main chain structure is all para-linkage for P1NH and both para- and meta-linkage for P2NH, with the same pendant electron-withdrawing benzimidazolyl and polar diethanolaminohexyloxy groups. Both copolymers possess excellent thermal stability ( Td > 300 °C, Tg > 100 °C) due to their rigid backbones. In addition, the pendant groups effectively lower LUMO (∼ −2.70 eV) and HOMO (∼ −5.70 eV) levels, resulting in improved electron-transporting and hole-blocking capabilities. Multilayer yellow-emitting PLEDs with a configuration of ITO/PEDOT:PSS/SY/ETL/LiF/Al were successfully fabricated by the spin-coating process. The maximum luminance and maximum current efficiency of the P1NH-based device were 12,881 cd/m2 and 10.94 cd/A, respectively, superior to the performance of P2NH-based device (4938 cd/m2, 3.70 cd/A) and the device without ETL (8690 cd/m2, 2.78 cd/A). Current results indicate that P1NH is highly effective in enhancing electron transport and device performance. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2494-2505 [ABSTRACT FROM AUTHOR]

ABSTRACT Carrier balance is essential to obtain efficient emission in polymer light-emitting diodes (PLEDs). A new polymer 3P5O composed of alternating p-terphenyl and tetraethylene glycol ether segments is designed and synthesized by the Suzuki coupling reaction and successfully employed as hole-buffer layer to improve carrier balance. Multilayer PLEDs [ITO/PEDOT:PSS/ 3P5O/SY/LiF/Al], with Super Yellow (SY) as the emitting layer and 3P5O as the hole-buffer layer, reveal maximum luminance (17,050 cd/m2) and maximum current efficiency (6.6 cd/A) superior to that without the hole-buffer layer (10,017 cd/m2, 3.0 cd/A). Moreover, it also shows better performance than that using conventional BCP as hole-blocking layer [ITO/PEDOT:PSS/SY/BCP/LiF/Al (80 nm): 13,639 cd/m2, 4.1 cd/A]. The performance enhancement has been attributed to hole-buffering characteristics of 3P5O that results in improved carrier recombination ratio and wider carrier recombination region. Current results indicate that the 3P5O is a promising hole-buffer polymer to enhance the performance of optoelectronic devices. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 785-794 [ABSTRACT FROM AUTHOR]

Naturally occurring forms of materials have complex morphology and excellent performance, which provides new strategies for synthesising materials. In this paper, strontium oxalate crystals with different morphologies can be obtained simultaneously on either side of the membrane of mung bean sprouts (MBS). The as-obtained products were characterised by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of ethylene diamine tetraacetic acid (EDTA) on the morphologies was investigated and discussed. The results showed that EDTA played a more important role in the formation of the products inside the MBS membrane. A presumable mechanism was proposed. This research may provide insights into the cooperation between bionic research and living vegetal cells. [ABSTRACT FROM AUTHOR]

Two cobalt(II) complexes [Co(QCT)2]·Cl·1.5H2O (1) (QCT = quinoline-2-carboxaldehyde thiosemicarbazone) and [Co(QCMT)(CH3OH)Cl2] (2) (QCMT = quinoline-2-carboxaldehydeN4-methyl-thiosemicarbazone) have been synthesized and structurally characterized. Complex1crystallizes in a triclinic system with space groupP–1 and complex2crystallizes in a monoclinic system with space groupP2(1)/n. In both complexes the cobalt(II) center is six coordinated with distorted octahedral geometry. The interactions of two complexes with CT-DNA were investigated by electronic absorption spectra, circular dichroism (CD) spectra and fluorescence spectra. Results suggest that the complexes bind to DNAviagroove binding mode, and complex2has stronger binding ability than complex1. Thein vitrocytotoxicity has been tested against the human lung adenocarcinoma cell line A-549, cisplatin-resistant cell line A-549/CDDP, and human breast adenocarcinoma cell line MCF-7. Complex2is more cytotoxic than complex1, and both of them show higher cytotoxicity than the parent ligands alone. Compared with cisplatin, the two cobalt(II) complexes are more active against A-549/CDDP and MCF-7 cell lines at most experimental concentrations. Notably, although complex 2 is found to be less effective than cisplatin against the parent cell line A-549, it is much more effective than cisplatin against the resistant cell A-549/CDDP. [ABSTRACT FROM PUBLISHER]

Highlights: [•] Microbial production of chemicals is an attractive alternative to chemical synthesis. [•] An integrated approach would be required to construct robust microbial chemical factories. [•] Computational algorithms allow for systematic design. [•] Novel modules and methods make engineering faster and easier. [•] Integrative analysis advances multiple-objective optimization. [Copyright &y& Elsevier]

A synthesis of N-ethyl- n-butylamine with simple separation method in a fixed-bed reactor using CuO-NiO-PtO/γ-AlO as the catalyst was proposed and investigated. The present catalytic system gave high activity and good selectivity, and the reaction conditions such as temperature and liquid hourly space velocity were optimized. Since no water was generated, the protocol proved to be easy to separate, and N-ethyl- n-butylamine was collected at 110 °C by distillation. The yield and the purity were 60.7 and 99.5 %, respectively. [ABSTRACT FROM AUTHOR]

A new macrocyclic dinuclear Zn(II) complex, [Zn2(OAc)L] · ClO4 (H2L was obtained by condensation between 3,3′-(ethane-1,2-diylbis(benzylazanediyl))bis(methylene)bis(2-hydroxy-5-methylbenzaldehyde) and aniline (1 : 2 molar ratio)), was synthesized and characterized by spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The interactions of the complex with DNA have been measured by UV spectroscopy and viscosity experiment. The interaction of the complex with calf thymus DNA has a binding constant of 1.18 × 104 mol−1 L. Phosphate hydrolysis of the complex was investigated using bis(4-nitrophenyl)phosphate as the substrate. The observed first-order rate constant is 4.23 × 10−5  s−1. [ABSTRACT FROM AUTHOR]

A series of sulfonyl-containing spiropyrans exhibiting negative photochromism were designed and synthesized. The prepared compounds show more stability for the brightly colored state in the dark-adapted than the colorless state under visible irradiation. Negative photochromic properties and fatigue resistance of these compounds in solution were confirmed by UV spectroscopy with time variation. Single-crystal X-ray diffraction analysis, NMR and variable-time absorption spectra studies suggest that the negative photochromism of the compounds involved a ring-opening spiro C O bond cleavage of the spiropyran followed by an intramolecular proton transfer. [ABSTRACT FROM AUTHOR]

• A microfluidic device for fiber spinning based on chemical synthesis were designed. • Formation mechanism of ordered coil structure by the microfluidic device was analyzed. • Magnetic microspring with ordered helical structure were fabricated using this microfluidic spinning setup. The helical structure is one of the most intriguing structures in nature; such an ingenious structure can be found from macromolecules to macroscopic areas, and the fabrication of helical structures has attracted research interest from mechanisms to applications. However, the fabrication of helical microfiber still remains a big challenge. In this study, a coaxial microfluidic device was made to continuously and controllably fabricate helical hydrogel microfibers with flexible shape by simply adjusting the flowrates. Various experimental conditions that can influence the diameter (d), pitch (p) and amplitude (A) of these formed coiled fibers were discussed. For the first time, the effects of G/M ratio of the alginates on the microfiber coiling phenomenon were examined. Additionally, magnetically responsive helical fibers were synthesized, and it is envisioned that hydrogel helical structure microfibers are highly versatile in different area, such as micro sensors, soft actuators and medical applications. [ABSTRACT FROM AUTHOR]

Abstract Series of (Zn, M) 3 (BO 3)(PO 4) (M = Ca, Mg):Ce3+ were synthesized by a high temperature solid state method, and the luminescence properties were investigated. Zn 3 (BO 3)(PO 4):Ce3+ presents two emission bands, which shows the different changing trends with increasing Ce3+ concentration. When introduced Mg2+ and Ca2+ into Zn 3 (BO 3)(PO 4), (Zn, M) 3 (BO 3)(PO 4) (M = Ca, Mg):Ce3+ also shows two emission bands because Ce3+ occupies three kinds of Zn sites and transits from 5d energy level to double ground state. Therefore, the two emission bands of Zn 3 (BO 3)(PO 4):Ce3+ should be assigned to the different occupancy sites of Ce3+. Moreover, the selective emission was realized and the emission intensity of Ce3+ was enhanced by the cationic substitution. Graphical Abstract Unlabelled Image Highlights • Series of (Zn, M) 3 (BO 3)(PO 4) (M = Ca, Mg):Ce3+ were synthesized. • (Zn, M) 3 (BO 3)(PO 4) (M = Ca, Mg):Ce3+ shows two emission bands. • Two emission bands of Zn 3 (BO 3)(PO 4):Ce3+ are assigned to the different occupancy sites. [ABSTRACT FROM AUTHOR]

Abstract: With the development of polymer-based biomaterials, aliphatic polyesters have attracted considerable interest because of their non-toxicity, non-allergenic property, and good biocompatibility. However, the hydrophobic nature and the lack of side chain functionalities of aliphatic polyesters limit their biomedical applications. In this study, we prepared four new polyesters: poly(sulfobetaine methacrylate)-, poly(2-methacryloyloxyethyl phosphotidylcholine)-, poly(ethylene glycol)-, and quaternized poly[(2-dimethylamino)ethyl methacrylate]-grafted poly(propargyl glycolide)-co-poly(ɛ-caprolactone). Their synthesis was conducted through ring-opening polymerization of acetylene-functionalized lactones and subsequent graft of bioactive units using click chemistry. The chemical structures of the polyesters were characterized through nuclear magnetic resonance and Fourier-transform infrared spectroscopy, and their physical properties (including molecular weight, glass transition temperature, and melting point) were determined using gel permeation chromatography and differential scanning calorimetry. For studies on their hydrophilicity, stability, and anti-bioadhesive property, a series of polymeric surfaces of these polyesters was prepared by coating them onto glass substrates. The hydrophilicity and stability of these polyester surfaces were examined by contact angle measurements and attenuated total reflection Fourier-transform infrared spectroscopy. Their anti-bioadhesive property was investigated through protein adsorption, as well as cellular and bacterial adhesion assays. The prepared polyesters showed good hydrophilicity and long-lasting stability, as well as significant anti-fouling property. The newly prepared polyesters could be developed as promising anti-fouling materials with extensive biomedical applications. [Copyright &y& Elsevier]