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Tunable aryl imidazolium ionic liquids acting as Br&oslash, nsted acid ionic liquids were found to be efficient catalysts for per-O-acetylation and reductive ring opening of benzylidene acetals. This method requires a truly catalytic amount of the least expensive available ionic liquids that are water-stable and reusable and also stable at room temperature. The reactions were obtained in one hour with good to excellent yields. These reactions can form C&minus, O and C&minus, H bonds with a high atom economy. Furthermore, the ionic liquid is an anomeric selective catalyst in per-O-acetylation and reductive ring opening of benzylidene acetals of sugar moieties.

Unique tunable aryl imidazolium ionic liquids successfully catalyzed Friedel&ndash, Crafts acylation and thioesterification in sealed tubes. These reactions can form a C&minus, C bond and a C&minus, S bond with high atom economy. Ionic liquids exhibited high activity and catalyzed essential reactions with good to excellent yields while retaining their catalytic activities for recycling.

Unique tunable aryl-imidazolium magnetic ionic liquids with dual functions as a solvent&ndash, catalyst and dual Br&oslash, nsted&ndash, Lewis acidity (B-L MILs) are applied for Friedel&ndash, Crafts alkylation without additional solvents. The catalytic properties of these B-L MILs in the Friedel&ndash, Crafts alkylation of p-xylene with benzyl chloride are investigated. The various reaction parameters, including the catalyst dosage, reaction time, reaction temperature, molar ratio of reactants, and reusability, are discussed. The results show that the B-L MIL 5c has more excellent product selectivity (&gt, 99%) and reactant conversion (&gt, 99%) under the following optimum conditions (reaction temperature = 80 &deg, C, reaction time = 0.5 h, molar ratio of p-xylene to benzyl chloride = 6:1, and catalyst 5c dosage = 1.0 mole %) than traditional catalysts reported in the previous literature. Specifically, due to the mesomeric effect between the FeCl4 anion and hydrogen atom at cationic moiety, the catalyst B-L MILs with the molar fraction of FeCl3 equal to 0.5 can be easily recovered and provide satisfactory catalytic activity after being re-used six times.

Herein, we describe the synthesis of tunable aryl imidazolium ionic liquid catalysts and tested for esterification of fatty acids to biodiesel. In this work, six tunable aryl imidazolium ionic liquids (TAIILs) 1a-1f were prepared. These ionic liquids were used as the economical and reusable catalysts for the synthesis of biodiesel fuels. The reaction has been preceded in a monophase at 80 °C for 4 h, after which the product was separated from the catalyst system by a simple liquid/liquid phase separation at room temperature with excellent yields. With the simple post-process, the catalyst is reusable at least 6 times. This novel method offers a short reaction time, good yields, and environmentally benign characteristics.

A new imidazolium ionic liquid polymer was synthesized and prepared as GC stationary phase for separation of coal tar samples. The coated capillary GC columns exhibited good thermal stability from room temperature to 380 °C, high separation efficiencies for coal tar samples, phthalates, PAHs and a maximum programmable temperature up to 400 °C.

The protective effect of an aqueous Pericarpium Granati extract (APG) against carrageenan-induced inflammatory damage in mice was investigated. The results showed that APG displayed radical scavenging, reducing activity, and liposome protection activity in acellular systems. The implementation of an HPLC helped identify polyphenolic components including epicatechin (11.9 mg/g), gallic acid (3.9 mg/g), ellagic acid (2.4 mg/g), ferulic acid (1.0 mg/g), quercetin (0.7 mg/g), and kaempferol (0.5 mg/g). APG administration in the range of 0.25–1.0 g/kg showed a concentration dependent inhibition on inflammatory response in carrageenan induced mice. The anti-inflammatory effects of APG could be related to the suppression of tissue nitric oxide and tumor necrosis factor-α, and associated with the reduction of lipid peroxidation and an increase in antioxidant enzyme activities including catalase, superoxide dismutase, and glutathione peroxidase in vivo. The results showed that APG might serve as a natural source of anti-inflammatory and antioxidative compounds in vivo.

This report is the first to study behaviors of nano-scale colloids prepared by long alkyl-chain imidazolium-based ionic liquids (LILs), namely, 1-hexadecyl-3-methylimidazolium hexafluorophosphate (C 16 MIMPF 6 ) and 1-hexadecyl-3-methylimidazolium bromide (C 16 MIMBr), as well as phosphatidylcholines (PCs), including hydrogenated soybean phosphatidylcholine (HSPC) and egg phosphatidylcholine (EPC). The effects of LILs on the physicochemical characteristics of PC vesicles are investigated using morphological observations and measurements of particle size, zeta potential, and fluorescence polarization. The experimental data reveal that the incorporation of LILs into PC vesicles shows significant changes in the size, turbidity, zeta potential, storage stability, and membrane fluidity of colloids, which may be correlated with the counter-ions of the LILs, the degree of saturation of the PCs, and the vesicular composition. In addition, the cell viability of HaCaT, A431, and SCC25 cells decreases in a dose-dependent manner and is associated with the composition of the PC vesicles that are incorporated with LIL. The apoptotic characteristic of cells is more significant for the PC vesicles that incorporate a higher molar ratio of LILs at dispersion concentrations of 0.1 and 1 mM. This work suggests that cytotoxicity is dependent on the counter-ions of LILs, the composition and concentration of dispersions, and the physicochemical properties of mixed LIL/PC colloids.

We synthesize a NIR MHI-148 dye, a lipophilic heptamethine cyanine, with capability in tumor-targeting property to accumulate in the mitochondria of tumor. In the context of MHI-148 dye, we demonstrate effective tumor targeting and NIR fluorescence in vitro and in vivo for MHI-148 as compared to ICG. A series of porous Gd silicates related nanoparticles, i.e. Gd silicate, Gd silicate@mSiO(2) (mSiO(2): mesoporous silica shell), and Gd(3+)-chelated Gd silicate@mSiO(2) (Gd(3+)-DOTA chelated on the mSiO(2)) are fabricated to demonstrate their magnetic resonance (MR) contrast imaging effects. Those Gd silicates related nanoparticles exhibit dual MR effect, expressing T(1)-brightened and T(2)-darkened effects, in lower magnetic field. In high magnetic field, an abnormal enhanced transverse relaxivity (r(2)) appears, showing an effective T(2)-lowering effect, possibly due to concentrated Gd amount and porous architecture. The r(2) value increases 4-5 times as the field strength increased from 3T to 7T. The Gd(3+)-chelated Gd silicate@mSiO(2) has given large r(2) (T(2)-lowering effect) up to 343.8 s(-1) mM(-1), which is even larger than the reported magnetic Fe(3)O(4) nanoparticles measured at the same field. Using a 9.4T animal micro MRI system we have seen effectively darken in signal for those porous Gd silicates related NPs, while no such phenomenon appears in commercial Gd-DOTA agent. The MHI-148 is then conjugated on the porous Gd silicate@mSiO(2) nanoparticles for a new paradigm with three functionalities for in vivo tumor targeting, near-infrared fluorescent and MR imaging by means of only using MHI-148 dye.

New tetrachlorocobaltate (II) and tetrachloromanganate (II) ionic compounds containing various counterdications were synthesized and characterized. These salts are soluble in polar solvents such as methanol and water. Physical properties such as thermal stability, melting point, and magnetic susceptibility of these salts depend on the cation or anion structure. The thermal stability of the phosphinium or imidazolium based salts is higher than that of the pyridinium or triethylaminonium analogues. The melting point of these compounds is following the order of triphenylphosphinium > pyridinium > imidazolium dications, and symmetrical dicationic salts > unsymmetrical ones. The magnetic susceptibility (χMT values) of tetrachloromanganate (II) anions-based salts is higher than that of tetrachlorocobaltate (II) anions-based salts. These dicationic salts exhibit weak antiferromagnetic interactions and have higher magnetic susceptibility than that of the previously reported tetrachloromanganate (II) and tetrachlorocobaltate(II) salts with monocationic counterion.

A series of unique tunable aryl-imidazolium magnetic ionic liquids (MILs) with dual acidity that contain both Br&oslash, nsted and Lewis acidic sites (abbreviated as B-L MILs) were synthesized and characterized using nuclear magnetic resonance and mass spectrometry. Physical properties, such as thermal properties, magnetic susceptibility, and Br&oslash, nsted and Lewis acidity, were measured. These properties were found to depend on the cation structure. These B-L MILs had good solubility in many organic solvents, good thermal stability, and low melting points, and exhibited magnet-like behavior. For these B-L MILs, the Br&oslash, nsted acidity was measured using ultraviolet-visible (UV-Vis), and the Lewis acidity was measured using Fourier transform infrared spectroscopy (FTIR). The results showed that B-L MILs with an electron-withdrawing group in the aryl-imidazolium moiety had higher Br&oslash, nsted acidity, whereas those with an electron-donating group had higher Lewis acidity. This type of ionic liquid, with both Br&oslash, nsted and Lewis acidic sites, is expected to be a useful solvent and catalyst for organic reactions.

New (μ-oxo)bis[trichloroferrate(III)] dianions-based ionic compounds that contain various counterdications were synthesized and characterized with regards to their crystal structures, thermal properties, and magnetic susceptibility. These salts are soluble in polar solvents such as methanol and water. The melting point of these compounds is affected by the dication following the order of triphenylphosphinium > pyridinium > imidazolium dications, and symmetrical dicationic salts > unsymmetrical ones. In these compounds, the trichloroferrate dianion exists in either a linear or a bent form, which is affected by the dications. Interestingly, the dicationic diferrate compounds show magnetic coupling constants fairly smaller than those reported in literature for diferrate salts in which monocations are the counterion. Furthermore, unlike the diferrate salts associated with separate monocations, the linear diferrate dicationic compounds show magnetic coupling constant lower than that of bent diferrate dicationic salts.

A series of dicationic ionic liquids, in which each dication is associated with both a hydrophobic anion and a hydrophilic anion, are synthesized. The thermal properties and solubility in organic solvents of these ILs are characterized. The ionic liquids show interesting properties, which are different from those of dicationic ionic liquids, in which each dication is associated with two identical anions.

Twelve main-chain-type polymerized ionic liquids that have alkylimidazolium cation units were prepared using simple synthetic processes. The polymers were prepared using the self-polymerization of a single monomer; no polymerization initiators were required. The thermal stability and solvent miscibility of these polymers were studied. Results show that the combined anions greatly influence the solubility and thermal stability of the polymers. Among these polymers, poly-alkylimidazolium bis(trifluoromethylsulfonyl)imide polymers exhibited the highest thermal stability (>400 °C), which makes them candidates for many applications.

To improve the transfection efficiency of polycations with DNA, we synthesized poly(ester-co-urethane)(PEU-g-PEI800) with short chain PEI800 in the side chain, and poly(ester-co-urethane)(PEU) without short chain PEI800. Both PEU-g-PEI800 and PEU, readily self-assembled with plasmid DNA (pCMV-betagal) in a HEPES buffer, were characterized by dynamic light scattering and zeta-potential. The results reveal that PEU-g-PEI800 and PEU were able to self-assemble particles with DNA and yield nano-sized complexes (200nm) with positive charge at N/P ratios of 20/1 and 120/1, respectively. The degradation studies indicate that the half-life of PEU-g-PEI800 and PEU in the HEPES buffer were 14 and 35h at pH 7.4, respectively. Titration studies were performed to determine the buffering capacities of the polymers. The COS-7 cell viabilities in the presence of PEU-g-PEI800/DNA, PEU/DNA, and PEI25k/DNA were studied. In addition, The PEU-g-PEI800/DNA complexes were able to transfect COS-7 cells in vitro with a high efficiency comparable to a well-known gene carrier PEI25k. The results indicate that PEU-g-PEI800 is an attractive cationic poly (ester-co-urethane) for gene delivery and an interesting candidate for further study.

Limited research has been performed on S-adenosylhomocysteine (SAH) or homocysteine (Hcy)-evoked cell damage in hepatic and neuronal cells. In this study, we assessed effects of SAH or Hcy on cell cytotoxicity and DNA damage in hepatic and neuronal cells and attempted to find the underlying mechanism. Cell cytotoxicity and DNA damage were evaluated in murine hepatic cells (BNL CL.2 cell line) and microglia cells (BV-2 cell line) with SAH or Hcy treatment for 48 h. The influences of SAH or Hcy on lipid peroxidation and DNA methylation were also measured in both cell lines. SAH (5-20 microM) or Hcy (1-5 mM) dose dependently inhibited cell cytotoxicity and enhanced DNA damage in both types of cells. Furthermore, SAH treatment markedly increased intracellular SAH levels and DNA hypomethylation, whereas Hcy caused minimal effects on these two parameters at much higher concentrations. Hcy significantly induced lipid peroxidation, but not SAH. The present results show that SAH might cause cellular DNA damage in hepatic and microglia cells by DNA hypomethylation, resulting in irreversible DNA damage and increased cell cytotoxicity. In addition, higher Hcy could induce cellular DNA damage through increased lipid peroxidation and DNA hypomethylation. We suggest that SAH is a better marker of cell damage than Hcy in hepatic and microglia cells.

SummaryThe recently sequenced genomes of several Aspergillus species have revealed that these organisms have the potential to produce a surprisingly large range of natural products, many of which are currently unknown. We have found that A. nidulans produces emericellamide A, an antibiotic compound of mixed origins with polyketide and amino acid building blocks. Additionally, we describe the discovery of four previously unidentified, related compounds that we designate emericellamide C–F. Using recently developed gene targeting techniques, we have identified the genes involved in emericellamide biosynthesis. The emericellamide gene cluster contains one polyketide synthase and one nonribosomal peptide synthetase. From the sequences of the genes, we are able to deduce a biosynthetic pathway for the emericellamides. The identification of this biosynthetic pathway opens the door to engineering novel analogs of this structurally complex metabolite.

Six polyvinylimidazolium based ionic liquids were prepared for use as stationary phases for gas chromatography. The influences of the attached side-chains (hexyl-, octyl- and phenylpropyl-) on the vinylimidazolium cations and of different counter ions (bromide, hexafluorophosphate, bis-trifluoromethanesulfonlyimide, and bis-trifluoroethanesulfonylimide) were studied. Linear solubility parameter experiments were conducted to characterize the specific interactions of these stationary phases. Some of the polymerized ionic liquid stationary phases exhibited unique structural selectivity. m-, and p-xylenes could be distinguished. The preparation of the polymerized ionic liquid column is simple and reliable. This work provides detailed information for designing polymerized ionic liquids, and shows that these materials have great potential extending the range of options for stationary phases in gas chromatography.

Poly-vinyloctylimidazolium ionic liquid polymers with different counter ions (bromide, hexafluorophosphate and bis-trifluoromethanesulfonylimide) were directly coated in capillary fused silica tubing as the stationary phases for gas chromatography. The anion effects on the polymers were examined and discussed. The results suggest that the poly-vinyloctylimidazolium, bis-trifluoromethanesulfonylimide capillary column has the highest thermal stability and separation efficiency. Column-to-column reproducibility was also studied. The results indicate that anions significantly influence ionic liquid polymers which give them potential to extend the range of options for the stationary phases in gas chromatography.

Breast cancer is one of the most common tumors in females. The therapeutic resistance of breast cancer has motivated the development of new agents for prevention and treatment. For the present study, several compounds were designed and analyzed for their antitumor activity in many cancer cell lines. 4-(3,4,5-Trimethoxyphenoxy) benzoic acid (compound 1) and its derivatives were selected for studying the anti-proliferative and cytotoxic effects on five human cancer cell lines. Results indicated that compounds 1 and 2 significantly suppressed the cell viability of MCF-7 and MDA-MB-468 cancer cells. However, compounds 1 and 2 had only minor effects on HepG2, Huh-7, and Hela cells. Moreover, compounds 1 and 2 exhibited a novel anti-tumor activity through the induction of cell-cycle arrest at G2/M and apoptosis in MCF-7 and MDA-MB-486 breast cancer cells. Both compounds reduced colony-forming ability in MCF-7 cells. Flow cytometric analysis indicated that caspase-3 activity was increased in response to treatment with compounds 1 and 2. Taken together, these findings suggest that the novel compounds 1 and 2 are potential anticancer agents with clinical promise for breast cancer therapy.

Despite the advances in cancer therapy and early detection, breast cancer remains a leading cause of cancer-related deaths among females worldwide. The aim of the current study was to investigate the antitumor activity of a novel compound, 4-(3,4,5-trimethoxyphenoxy)benzoic acid (TMPBA) and its mechanism of action, in breast cancer. Results indicated the relatively high sensitivity of human breast cancer cell-7 and MDA-468 cells towards TMPBA with IC50 values of 5.9 and 7.9 µM, respectively compared to hepatocarcinoma cell line Huh-7, hepatocarcinoma cell line HepG2, and cervical cancer cell line Hela cells. Mechanistically, TMPBA induced apoptotic cell death in MCF-7 cells as indicated by 4',6-diamidino-2-phenylindole (DAPI) nuclear staining, cell cycle analysis and the activation of caspase-3. Western blot analysis revealed the ability of TMPBA to target pathways mediated by mitogen-activated protein (MAP) kinases, 5' adenosine monophosphate-activated protein kinase (AMPK), and p53, of which the concerted action underlined its antitumor efficacy. In addition, TMPBA induced alteration of cyclin proteins’ expression and consequently modulated the cell cycle. Taken together, the current study underscores evidence that TMPBA induces apoptosis in breast cancer cells via the modulation of cyclins and p53 expression as well as the modulation of AMPK and mitogen-activated protein kinases (MAPK) signaling. These findings support TMPBA’s clinical promise as a potential candidate for breast cancer therapy.

1,5-Hydrogen atom transfer from α, β and γ carbons of cycloalkanones to an alkenyl or aryl radical on a side chain has been studied systematically. Deuterium labeling experiments and theoretical calculations were used to delineate this process. The results indicate that 1,5-hydrogen atom transfer is controlled mostly by conformational factors.

A general approach toward spiro[4.4]nonane structure based on the α-carbonyl radical cyclization has been developed. Efficient total synthesis of dimethyl gloiosiphone A (2) was achieved. Thus, alkylation of the anion of dimethylhydrazone of cyclopentanone with 5-iodopent-1-yne followed by hydrolysis gave ketone 4. Iodination of 4 via its TMS-enol ether yielded iodo ketone 7. Radical spiro-cyclization of 7 gave spiro ketone 10. Iodination of 10 afford iodo spiro ketone 23. Oxidation and iodination of 23 gave compound 24. Methylation of 24 furnished methoxy iodo enone 25. Substitution of iodide in 25 with methoxide produced dimethoxy enone 26. Allylic oxidation of 26 gave diketone 27. Treatment of 27 with OsO4 and N-methylmorpholine N-oxide gave dihydroxy ketone 28. Methylation of the primary alcohol group in 28 afforded dimethyl gloiosiphone A (2).

There is evidence that increased plasma cytokines, elevated brain levels of monoamines and hydroxyl radical production may be implicated in pathogenesis during heat stroke in rats. Acute treatment with a combined therapeutic approach has been repeatedly advocated in cerebral ischemia experiments. The aim of this study was to investigate whether the combined agent (mannitol and dexamethasone) has beneficial efficacy to improve the survival time (ST) and heat stroke-induced damage in experimental heat stroke. Urethane-anesthetized rats underwent instrumentation for the measurement of colonic temperature, mean arterial pressure (MAP), striatal cerebral blood flow (CBF), heart rate, and neuronal damage score. The rats were exposed to an ambient temperature (43 degrees C) to induce heat stroke. Concentrations of the ischemic and damage markers, dopamine, serotonin, and hydroxyl radical production in corpus striatum, and the plasma levels of tumor necrosis factor-alpha (TNF-alpha) were observed during heat stroke. After the onset of heat stroke, the heat stroke rats display decreased MAP, decreased CBF, increased the plasma levels of TNF-alpha, increased cerebral striatal monoamines and hydroxyl radical production release, and severe cerebral ischemia and neuronal damage compared with those of normothermic control rats. However, immediate treatment with the combined agent confers significant protection against heat stroke-induced arterial hypotension, systemic inflammation, cerebral ischemia, cerebral monoamines and hydroxyl radical production overloads, and improves neuronal damage and the ST in heat stroke rats. Our data suggest that administration of this combined agent seems to have more effective to ameliorate the heat stroke-induced neuronal damage and prolong the ST.

The total synthesis of dimethyl gloiosiphone A 2 was achieved via an α-carbonyl radical spirocyclization.

Imidazolium iodide ionic liquids have a relatively high viscosity, and, as consequence, mass-transport limitation problems restrict their use as solvents for electrolytes. In this study, a series of 1-alkyl-3-carboxypyridinium iodide molten salts, [ACP][I], was used as a gel electrolyte for dye-sensitized solar cells (DSSCs). Without addition of any nano-particles, small molecules, oligomers or polymer plasticizers, these [ACP][I] salts acted as a stiffener, plasticizing the liquid phase electrolyte. An investigation was carried out into the electrochemical properties of these [ACP][I]-based gel electrolytes, and they were found to have an impressively high diffusion constant (DI3−) of ∼28.5 × 10−6 cm2 s−1 and conductivity (σ) of ∼4.30 mS cm−1. The photovoltaic performance of this new redox couple was evaluated by employing nanocrystalline TiO2 films with different thicknesses. An energy conversion efficiency of 3.7% was achieved using an 8 μm TiO2 electrode, under simulated solar illumination (AM 1.5, 100 mW cm−2). This efficiency is comparable with the cells fabricated with the liquid electrolyte-Solaronix AN-50 (η 4.0%, reported in the literature).

A new main-chain type ionic homopolymer GC stationary phase which has high separation efficiencies for alcohols, phthalates and PAHs and a maximum programmable temperature of 400 °C was prepared and studied.

The total synthesis of dimethyl gloiosiphone A 2 was achieved via an α-carbonyl radical spirocyclization.

Background Increased systemic cytokines and elevated brain levels of monoamines, and hydroxyl radical productions are thought to aggravate the conditions of cerebral ischemia and neuronal damage during heat stroke. Dexamethasone (DXM) is a known immunosuppressive drug used in controlling inflammation, and hydroxyethyl starch (HES) is used as a volume-expanding drug in cerebral ischemia and/or cerebral injury. Acute treatment with a combined therapeutic approach has been repeatedly advocated in cerebral ischemia experiments. The aim of this study is to investigate whether the combined agent (HES and DXM) has beneficial efficacy to improve the survival time (ST) and heat stroke-induced cerebral ischemia and neuronal damage in experimental heat stroke. Methods Urethane-anesthetized rats underwent instrumentation for the measurement of colonic temperature, mean arterial pressure (MAP), local striatal cerebral blood flow (CBF), heart rate, and neuronal damage score. The rats were exposed to an ambient temperature (43 degrees centigrade) to induce heat stroke. Concentrations of the ischemic and damage markers, dopamine, serotonin, and hydroxyl radical productions in corpus striatum, and the serum levels of interleukin-1 beta, tumor necrosis factor-alpha and malondialdehyde (MDA) were observed during heat stroke. Results After heat stroke, the rats displayed circulatory shock (arterial hypotension), decreased CBF, increased the serum levels of cytokines and MDA, increased cerebral striatal monoamines and hydroxyl radical productions release, and severe cerebral ischemia and neuronal damage compared with those of normothermic control rats. However, immediate treatment with the combined agent at the onset of heat stroke confers significant protection against heat stroke-induced circulatory shock, systemic inflammation; cerebral ischemia, cerebral monoamines and hydroxyl radical production overload, and improves neuronal damage and the ST in rats. Conclusions Our results suggest that the combination of a colloid substance with a volume-expanding effect and an anti-inflammatory agent may provide a better resuscitation solution for victims with heat stroke.