Structure Evolution of Synthetic Amino Acids-Derived Basic Ionic Liquids for Catalytic Production of Biodiesel

A two-step strategy was attempted to develop the best amino acid-based basic ionic liquids for catalytic production of biodiesel via transesterification. Cholinium with various amino acids as paired anions were first synthesized to screen anionic moiety. Arginine and histidine were selected for further structural evolution by varying the substituents of tetraammonium cation. Tetrabutylammonium arginine ([TBA]­[Arg]) was found to be the most effective catalyst to obtain 98.0%–99.8% yield of biodiesel at 80 °C within 15 min with catalyst loading of 28.84 mmol/100 g high oleic sunflower oil. ¹³C NMR spectra of reactants and products certified the progress of transesterification structurally. Biodiesel yield of 98.80% was obtained under the optimal conditions: catalyst loading 6% (oil basis, w/w), temperature 90 °C, methanol to oil mole ratio 9:1, and 15 min reaction. The catalytic transesterification by [TBA]­[Arg] was applicable for different alkyl alcohols, but the activity decreased with increasing alkyl chain length. The catalyst did not show specificity and preference to different glycerides and different fatty acids. The strong protonizability of the guanidine moiety in [Arg]⁻ and stability of [TBA]⁺, [TMA]⁺ and [Ch]⁺ in methanol are suggested to be responsible for the high catalytic activity of the ILs. The developed catalyst significantly reduced the reaction time and might be greener and more sustainable due to the properties of the substrates and the preparation in water

Complete Utilization of Rapeseed Meal to Produce Lipophilic Antioxidants, Protein, and Monosugars in a Concordant Manner

The possibilities of complete utilization of rapeseed meal to produce lipophilic phenolic compounds, protein, and monosugars were evaluated extensively in this work. Advanced techniques including NMR and MS were employed for confirming the occurrence of the proposed reaction structurally. Lipophilization of the major phenolic compound in rapeseed meal, sinapine, by transesterification reaction was achieved in a solvent-free system with optimal conditions of 10 mg NaOH/g meal, 70 °C, 15 mL methanol/g meal, and 15 min. Sinapate alkyl esters yields were decreased gradually with longer chain alcohols. However, the purity of the targeted compounds in corresponding alcohols was improved due to low solubilities of the other polar compounds. After sinapate alkyl esters production, the solid residue was soaked in NaOH solution at room temperature for protein extraction and 50 mg protein/g meal with protein content of 77% was obtained. The above two procedures played roles as pretreatments of the carbohydrate. Hexose yield of 67% was reached without any other pretreatments. This work suggests the big possibilities of producing high value products from rapeseed meal in a concordant manner

Modulation of the Electronic Properties of Ultrathin Black Phosphorus by Strain and Electrical Field

The structural and electronic properties of the bulk and ultrathin black phosphorus and the effects of in-plane strain and out-of-plane electrical field on the electronic structure of phosphorene are investigated using first-principles methods. The computed results show that the bulk and few-layer black phosphorus from monolayer to six-layer demonstrates inherent direct bandgap features ranging from 0.5 to 1.6 eV. Interestingly, the band structures of the bulk and few-layer black phosphorus from X point via A point to Y point present degenerate distribution, which shows totally different partial charge dispersions. Moreover, strong anisotropy in regard to carrier effective mass has been observed along different directions. The response of phosphorene to in-plane strain is diverse. The bandgap monotonically decreases with increasing compressive strain, and semiconductor-to-metal transition occurs for phosphorene when the biaxial compressive reaches −9%. Tensile strain first enlarges the gap until the strain reaches around 4%, after which the bandgap exhibits a descending relationship with tensile strain. The bandgaps of the pristine and deformed phosphorene can also be continuously modulated by the electrical field and finally close up at about 15 V/nm. Besides, the electron and hole effective mass along different directions exhibits different responses to the combined impact of strain and electrical field

Fasudil Protects the Heart against Ischemia-Reperfusion Injury by Attenuating Endoplasmic Reticulum Stress and Modulating SERCA Activity: The Differential Role for PI3K/Akt and JAK2/STAT3 Signaling Pathways

<div><p>Disordered calcium homeostasis can lead to endoplasmic reticulum (ER) stress. Our previous data showed that time course activation of ER stress contributes to time-related increase in ischemia-reperfusion (I/R) injury. However, it has not been tested whether PI3K/Akt and JAK2/STAT3 pathways play differential roles in reducing ER stress to protect the heart. In the present study, using fasudil which is a specific inhibitor of ROCK, we aimed to investigate whether improved SERCA expression and activity accounts for reduced ER stress by ROCK inhibition, specifically whether PI3K/Akt and JAK2/STAT3 pathways are differentially involved in modulating SERCA activity to reduce ER stress and hence I/R injury. The results showed that during the reperfusion period following 45 min of coronary ligation the infarct size (IS) increased from 3 h of reperfusion (45.4±5.57%) to 24 h reperfusion (64.21±5.43, P<0.05), which was associated with ER stress dependent apoptosis signaling activation including CHOP, Caspase-12 and JNK (P<0.05, respectively).The dynamic ER stress activation was also related to impaired SERCA activity at 24 h of reperfusion. Administration of fasudil at 10 mg/Kg significantly attenuated ROCK activation during reperfusion and resulted in an improved SERCA activity which was closely associated with decreases in temporal activation of ER stress and IS changes. Interestingly, while both PI3K/Akt and JAK2/STAT3 signaling pathways played equal role in the protection offered by ROCK inhibition at 3 h of reperfusion, the rescued SERCA expression and activity at 24 h of reperfusion by fasudil was mainly due to JAK2/STAT3 activation, in which PI3K/Akt signaling shared much less roles.</p> </div

Low-Molecular-Weight Organo- and Hydrogelators Based on Cyclo(l‑Lys‑l‑Glu)

Four cyclo­(l-Lys-l-Glu) derivatives (<b>3</b>–<b>6</b>) were synthesized from the coupling reaction of protecting l-lysine with l-glutamic acid followed by the cyclization, deprotection, and protection reactions. They can efficiently gelate a wide variety of organic solvents or water. Interestingly, a spontaneous chemical reaction proceeded in the organogel obtained from <b>3</b> in acetone exhibiting not only visual color alteration but also increasing mechanical strength with the progress of time due to the formation of Schiff base. Moreover, <b>6</b> bearing a carboxylic acid and Fmoc group displayed a robust hydrogelation capability in PBS solution. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed the characteristic gelation morphologies of 3D fibrous network structures in the resulting organo- and hydrogels. FT-IR and fluorescence analyses indicated that the hydrogen bonding and π–π stacking play as major driving forces for the self-assembly of these cyclic dipeptides as low-molecular-weight gelators. X-ray diffraction (XRD) measurements and computer modeling provided information on the molecular packing model in the hydrogelation state of <b>6</b>. A spontaneous chemical reaction proceeded in the organogel obtained from <b>3</b> in acetone exhibiting visual color alteration and increasing mechanical strength. <b>6</b> bearing an optimized balance of hydrophilicity to lipophilicity gave rise to a hydrogel in PBS with MGC at 1 mg/mL

Different SERCA isoform expressions were quantified.

<p>Using the same heart tissue described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048115#pone-0048115-g002" target="_blank">figure 2</a>, western blotting was performed using specific antibodies to measure the expression levels of different isoforms of SERCA. Panel A showed representative bands of SERCA2a for each group rats with quantification shown in bar graph, Panel B showed quantification of SERCA2b, and Panel C for SERCA3. All data expressed as mean±SD. * denotes P<0.05 vs. Sham groups; †, P<0.05 vs. I/R group at the same time point.</p

Enhanced Synthesis of Alkyl Galactopyranoside by <i>Thermotoga naphthophila</i> β‑Galactosidase Catalyzed Transglycosylation: Kinetic Insight of a Functionalized Ionic Liquid-Mediated System

Green synthesis is of pivotal importance for environmental sustainability. This work reports a novel approach to synthesize an array of alkyl galactopyranosides using thermophilic β-galactosidase from <i>Thermotoga naphthophila</i> RKU-10 (TN1577) as biocatalyst and milk processing waste lactose as galactosyl donor. Ammoeng 102 (only 2.5% addition of total reaction volume), a functionalized ionic liquid (IL) containing tetraaminum cation with C₁₈ acyl and oligoethylene glycol, is identified as the most promising one from a variety of structurally diverse ILs, affording a 2.37-fold increase in octyl galactopyranoside yield compared to the buffer system. Up to 18.2 g L^–1 octyl galactopyranoside could be produced in 7 h, which is significantly higher than any previous report in terms of time-space efficiency. Kinetic study and COSMO-RS <i>in silico</i> predictions elucidate that the thermophilic nature of TN1577 β-galactosidase, increased solubility of substrate, suppression of hydrolysis, and excellent biocompatibility of Ammoeng 102 with enzyme (allowing TN1577 β-galactosidase to perform optimal catalysis up to 95 °C) are the main driving forces. The general applicability of the Ammoeng 102 system is verified, by which a series of alkyl galactopyranosides are successfully synthesized with <i>n</i>-butanol to <i>n</i>-tetradecanol as alkyl acceptors and lactose as galactosyl donor

ROCK activity was measured in the presence of either PI3K/Akt inhibitor, LY294002, or JAK2 inhibitor, AG490, by quantifying the phosphorylation level of ERM.

<p>Representative bands for p-ERM and total ERM were shown for each group rats (n = 6 for either sham or I/R group rats treated with LY294001 or AG490, the other group rats are the same as shown above). All data expressed as mean±SD. * denotes P<0.05 vs. sham group.</p

Both PI3K/Akt and JAK2/STAT3 pathway activities were quantified.

<p>Using the same heart tissue described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048115#pone-0048115-g002" target="_blank">figure 2</a>, western blotting was performed for each group targeting phosphorylation levels of Akt (representative protein bands shown in Panel A and quantified in bar graph in Panel B), phosphorylation levels of JAK2 (Panel C and D) and STAT3 (Panel E and F). All data expressed as mean±SD. * denotes P<0.05 vs. Sham groups; †, P<0.05 vs. I/R group at the same time point and #, P<0.05 vs. I/R+fasudil group at 3 hours of reperfusion.</p