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Naturally occurring conjugated allenynes are of general interest owing to their potent and various biological activities. The 1,5‐H transfer of alka‐1,4‐diyn‐3‐yl amines would be one of the most straightforward yet challenging approaches to such compounds since, in principle, two regioisomers may be formed involving two C−C triple bonds. Herein, a catalytic recipe of copper halides with mixed oxidation states, i.e. CuCl/CuBr2, has been identified to address the issues of the side reaction of conjugate addition and the selectivity of 1,5‐H transfer of alka‐1,4‐diyn‐3‐yl amines in EATA (enantioselective allenation of terminal alkynes) reaction involving 2‐alkynals. This method provided various allenynes with excellent enantioselectivities, and was also applied to the first highly enantioselective total synthesis of natural product scorodonin. Mechanistic studies and DFT calculations elucidated the regioselectivity for the observed 1,5‐H transfer. [ABSTRACT FROM AUTHOR]

We have prepared an ultra‐large core, high numerical aperture (NA) chalcogenide (ChG) step‐index fiber (SIF) with a mode area of >43 600 μm2 at the wavelength of 5.5 μm by an improved extrusion method. The fiber based on two ChG glasses with similar softening temperature has a core diameter of 339.0 μm and ultra‐thin cladding. The fiber exhibits a minimum loss of 1.75 dB/m at 9.74 μm and an optical loss of <5.0 dB/m from 5.3 to 10.8 μm. Broadband supercontinuum (SC) covering from 1.2 μm to 13.7 μm has been generated in a 17‐cm‐long ultra‐large mode area fiber with large core and high NA. All these show that, the fiber possesses the potential for high‐power infrared laser transmission. [ABSTRACT FROM AUTHOR]

Herein, an injectable photothermal hydrogel system containing a therapeutic radionuclide 188Re is studied for combined radioisotope therapy and photothermal therapy (PTT) of cancer. A dopamine‐conjugated poly(α,β‐aspartic acid) copolymer (PDAEA) is used to trigger a sol–gel phase transition in mixture with Fe3+ ions, rapidly forming a gel by simply mixing PDAEA and FeCl3 phosphate buffer saline solutions. The injectable hydrogel exhibits strong near‐infrared light absorbance and can efficiently convert light into a heating effect for local PTT treatment. The obtained hydrogel possesses a porous 3D microstructure, and can be utilized for radionuclide loading. After the Na188ReO4 loading, the hydrogel is intratumorally injected into the tumor of mice bearing 4T1 murine breast cancer cells for studying the tumor retention and therapeutic efficiency. In vivo results show that Na188ReO4‐loaded hydrogel exhibits significantly longer time in the tumor sites than that of free Na188ReO4. The tumor growth of mice treated with Na188ReO4‐loaded hydrogel under near‐infrared radiation is significantly inhibited compared with control groups. Therefore, the results show that the developed strategy using an injectable and biocompatible hydrogel may promote the applications of radioisotope therapy and photothermal therapy for cancer. [ABSTRACT FROM AUTHOR]

Herein, we report a nickel‐catalyzed crossing‐coupling reaction for the synthesis of diaryl ethers. The desired products are achieved by coupling heterocyclic alcohols with aryl bromides bearing strong electron withdrawing nitro group under the catalyst system of NiCl2(PPh3)2 and weak base KHCO3. This mild reaction exhibits a broad functional group tolerance. Compound 4 as an important intermediate is suitable for further structural modification of MALT1 inhibitor MI‐2. [ABSTRACT FROM AUTHOR]

The observation of an unexpected oxidative rearrangement coupling reaction led to the development of a novel method for the efficient functionalization of tetrahydro-β-carbolines (THβCs). The treatment of THβCs with photogenerated singlet oxygen (1O2) afforded unstable dioxetanes, which underwent further transformation to form new bonds in the presence of trifluoroacetic acid. This operationally simple protocol exhibits broad functional-group tolerance and is suitable for the late-stage functionalization of complex druglike molecules. [ABSTRACT FROM AUTHOR]

An injectable dual redox responsive diselenide-containing poly(ethylene glycol) (PEG) hydrogel was successfully developed by combining the conceptions of injectable hydrogels and dual redox responsive diselenides. In the first step, four-armed PEG was modified with N-hydroxysuccinimide (NHS)-activated esters and thereafter, crosslinked by selenocystamine crosslinkers to form injectable hydrogels via the rapid reaction between NHS-activated esters and amino groups. The cross-sectional morphology, mechanical properties, and crosslinking modes of hydrogels were well characterized via scanning electron microscope (SEM), rheological measurements, and Fourier transform infrared spectra, respectively. In addition, the oxidation- and reduction-responsive degradation behaviors of hydrogels were observed and analyzed. The model drug, rhodamine B, was encapsulated in the hydrogel. The drug-loaded hydrogel exhibited a dual redox responsive release profile, which was consistent with the degradation experiments. The results of all experiments indicated that the formulated injectable dual redox responsive diselenide-containing PEG hydrogel can have potential applications in various biomedical fields such as drug delivery and stimuli-responsive drug release. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2451-2460, 2017. [ABSTRACT FROM AUTHOR]

Hydrogel systems based on cross-linked polymeric materials with adhesive properties in wet environments have been considered as promising candidates for tissue adhesives. The 3,4-dihydroxyphenylalanine (DOPA) is believed to be responsible for the water-resistant adhesive characteristics of mussel adhesive proteins. Under the inspiration of DOPA containing adhesive proteins, a dopamine-modified poly(α,β-aspartic acid) derivative (PDAEA) was successfully synthesized by successive ring-opening reactions of polysuccinimide (PSI) with dopamine and ethanolamine, and an injectable bioadhesive hydrogel was prepared via simply mixing PDAEA and FeCl3 solutions. The formation mechanism of the hydrogel was investigated by ultraviolet-visible (UV-vis) spectroscopic, Fourier transformation infrared (FT-IR) spectroscopic, visual colorimetric measurements and EDTA immersion methods. The study demonstrated that the PDAEA-Fe3+ hydrogel is a dual cross-linking system composed of covalent and coordination crosslinks. The PDAEA-Fe3+ hydrogel is suitable to serve as a bioadhesive agent according to the rheological behaviors and the observed significant shear adhesive strength. The slow and sustained release of the model drug curcumin from the hydrogel in vitro demonstrated the hydrogel could also be potentially used for drug delivery. Moreover, the cytotoxicity tests in vitro suggested the prepared polymer and hydrogel possessed excellent cytocompatibility. All the results indicated that the dopamine modified poly(α,β-aspartic acid) derivative based hydrogel was a promising candidate for bioadhesive drug delivery system. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1000-1008, 2017. [ABSTRACT FROM AUTHOR]

N,N-Dimethylaminophenyl moiety is a common fragment in medicinal chemistry as several pharmaceuticals bearing this privileged motif are on the market and under clinical evaluation. Oxidative N-demethylation is generally regarded as the major metabolic pathway. However, pharmacokinetics, metabolites studies as well as the further structural modification are precluded by the impracticality of chemical synthesis. Here we report that acetic acid can significantly accelerate visible-light photoredox catalyzed N-demethylation of N,N-dimethylaminophenyl derivatives. This approach is easy for large scale reaction and even for potential industrial manufacture. [ABSTRACT FROM AUTHOR]

ABSTRACT Two series of renewable nipagin and eugenol-based copoly(ether ester)s, PDN11− xE1 x and PDN11− xE2 x ( x = 0%, 10%, 20%, 30%, 40%, 50%), were prepared in the melt with 1,10-decanediol as a comonomer. The synthesized poly(ether ester)s have weight-average molecular weights ( Mw) in the range of 20,400-37,200 g mol−1, and dispersity ( D) values between 1.7 and 1.9. Thermal gravimetric analysis (TGA) reveal that all the poly(ether ester)s exhibit a two-step degradation mechanism with an initial degradation temperature above 350 °C. Results from differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD) analyses demonstrate that the poly(ether ester)s are all semicrystalline materials with glass transition temperature ( Tg) values ranging between −21.3 and −8.3 °C. The insertions of phenoxy-ether linkage and eugenol-derived composition have significant influence on the Tg, crystallinity, Young's modulus, and tensile strength, as well as the toughening effect and degradability. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2171-2183 [ABSTRACT FROM AUTHOR]

A pH-responsive polymeric micelle based on poly(aspartamide) derivative was explored as an efficient acid-triggered anticancer drug delivery system. Poly(α,β- l-asparthydrazide) (PAHy) was prepared by aminolysis reaction of polysuccinimide with hydrazine hydrate. Poly(ethylene glycol) and aliphatic chain (C18) were conjugated onto PAHy to afford an amphiphilic copolymer with acid-liable hydrazone bonds. The structure of the resulting copolymer and its self-assembled micelles were confirmed by 1H NMR, FTIR, DLS, and TEM. Furthermore, doxorubicin (DOX) was loaded into the polymeric micelles via the hydrophobic interaction between the C18 group and DOX molecules, and the π-π staking between the hydrazone conjugated DOX and free DOX molecules. Results showed that the DOX loaded nanoparticle (NP) was relatively stable under physiological conditions, while the DOX was quickly released in response to acidity due to the shedding of mPEG shells and dissociating of C18 segments because of the pH-cleavage of intermediate hydrazone bonds. In addition, the DOX loaded micelles presented a high cytotoxic activity against tumor cells in vitro. This pH responsive NP has appeared highly promising for the targeted intracellular delivery of hydrophobic chemotherapeutics in cancer therapy. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3045-3053, 2015. [ABSTRACT FROM AUTHOR]

An injectable hydrogel via hydrazone cross-linking was prepared under mild conditions without addition of cross-linker or catalyst. Hydrazine and aldehyde modified poly(aspartic acid)s were used as two gel precursors. Both of them are water-soluble and biodegradable polymers with a protein-like structure, and obtained by aminolysis reaction of polysuccinimide. The latter can be prepared by thermal polycondensation of aspartic acid. Hydrogels were prepared in PBS solution and characterized by different methods including gel content and swelling, Fourier transformed-infrared spectroscopy, and in vitro degradation experiment. A scanning electron microscope viewed the interior morphology of the obtained hydrogels, which showed porous three-dimensional structures. Different porous sizes were present, which could be well controlled by the degree of aldehyde substitution in precursor poly(aspartic acid) derivatives. The doxorubicin-loaded hydrogels were prepared and showed a pH-sensitive release profile. The release rate can be accelerated by decreasing the environmental pH from a physiological to a weak acidic condition. Moreover, the cell adhesion and growth behaviors on the hydrogel were studied and the polymeric hydrogel showed good biocompatibility. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 628-638, 2014. [ABSTRACT FROM AUTHOR]

The article focuses on the catalyst-controlled high chemoselective coupling and oxygenation of olefins. It states that the catayst-controlled high chemoselective coupling and oxygenation for direct synthesis of alcohols, ketones, and diketones are vital synthons in organic chemistry. It adds that the selectivity for the synthesis of alcohols ketones, and ligands is switched by the selection of diferent catalysts.

Hollow microcapsules, composed of pH responsive polyelectrolytes via a layer-by-layer (LBL) adsorption technique, were prepared. Linear or star-shaped poly(glycerol metha crylate)s (PGOHMAs) modified with 1,4-butanediamine and 1,2-ethanediamine (EDA) were synthesized and used as polycations. Poly(acrylic acid) was employed as polyanion and SiO2 (about 170 nm) as template. After LBL absorption, SiO2 cores were removed by HF treatment. The particle size and zeta potential were measured by dynamic light scattering, showing that the diameter of star-shaped amino-PGOHMA was larger than linear counterpart. The LBL assembly and core-etching process were evidenced by scanning electron microscope, transmission electron microscope, and energy dispersive spectrometer. The cytotoxicity experiments on human umbilical vein endothelial cells were carried out to evaluate the toxicity of LBL assembly. The star-shaped and EDA-modified PGOHMA exhibited better cell viability. The microcapsules were then used to load an anticancer drug, doxorubicin hydrochloride. High loading capacity (about 42%) and entrapment efficiency (84%) were obtained for star-shaped polymer-based microcapsules. The cumulative release rate was evaluated in vitro, showing faster release at an acidic condition compared to neutral pH. Confocal laser scanning microscopy evidenced the successful cellular uptake of DOX-loaded microparticles. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by sustained fibrotic lesions. Orally administered drugs usually fail to efficiently penetrate the interstitial tissue and reach the lesions, resulting in low treatment efficiency. Luteolin (Lut) is a natural flavonoid, active metabolites of which possess antioxidant, anti‐inflammatory, anti‐fibrotic, and anti‐apoptotic properties. In this study, a nano‐formulation is developed by loading Lut into hyaluronidase nanoparticles (Lut@HAase). These Lut@HAase nanoparticles (NPs) exhibit small size and good stability, suitable for noninvasive inhalation and accumulation in the lungs, and hyaluronidase at the site of lesions can degrade hyaluronic acid in the interstitial tissue, enabling efficient penetration of Lut. Lut's therapeutic effect, when administered via NPs, is studied both in vitro (using MRC5 cells) and in vivo (using IPF mice models), and its anti‐fibrotic properties are found to inhibit inflammation and eliminate reactive oxygen species. Conclusively, this study demonstrates that Lut@HAase can improve lung function and enhance survival rates while reducing lung damage with few abnormalities during IPF treatment. [ABSTRACT FROM AUTHOR]

An alkenylation of indoles at C-3 is developed through tandem addition and oxidative dehydration. [ABSTRACT FROM AUTHOR]