Ultrasound-assisted extraction of polyphenols from pine needles (Pinus elliottii): Comprehensive insights from RSM optimization, antioxidant activity, UHPLC-Q-Exactive Orbitrap MS/MS analysis and kinetic model.

Extracting polyphenolic bioactive compounds from Pinus elliottii needles, a forestry residue, promises economic and environmental benefits, however, relevant experimental data are lacking. Herein, a comprehensive investigation of the polyphenolic composition of pine needles (PNs) was carried out. Ultrasound-Assisted Extraction (UAE) was applied to extract the polyphenolic compounds of pine needles. The optimal conditions of extracts were determined by Response Surface Methodology (RSM). The maximum total phenolic content (TPC) of 40.37 mg GAE/g PNs was achieved with solid-liquid ratio of 1:20, 60 % ethanol, and 350 W for 25 min at 45 °C. Polyphenolic extracts showed antioxidant activity in scavenging free radicals and reducing power (DPPH, IC50 41.05 µg/mL; FRAP 1.09 mM Fe2+/g PNs; ABTS, IC50 214.07 µg/mL). Furthermore, the second-order kinetic model was also constructed to describe the mechanism of the UAE process, with the extraction activation energy estimated at 12.26 kJ/mol. In addition, 37 compounds in PNs were first identified by UHPLC-Q-Exactive Orbitrap MS/MS, including flavonoids and phenolic acids. The results suggest that Ultrasound-Assisted is an effective method for the extraction of natural polyphenolic compounds from pine needles and this study could serve as a foundation for utilizing phenolics derived from PNs in the food and pharmaceutical industries.

Experimental Study on Bubble Dynamics and Mass Transfer Characteristics of Coaxial Bubbles in Petroleum-Based Liquids.

Petroleum-based liquids are from an important petroleum-based polymer, whose application and preparation involve multiple operations related to gas-liquid two-phase flow. Due to insufficient research on gas-liquid two-phase flow, there is a gap in bubble dynamics and mass transfer characteristics in petroleum-based liquids. Accordingly, we have systematically investigated the bubble formation process, bubble rising dynamics, and mass transfer of coaxial bubbles. Herein, the contour of bubbles was obtained for analyzing the bubble formation process. It was found that the increase of gas flow rate contributed to the increase of bubble generation size, while the liquid viscosity had an inhibitory influence on the increase of bubble generation size. Moreover, the variation of bubble rising velocity was considered and the force analysis of the rising bubble was provided. A new model of drag coefficient applicable to petroleum-based liquids was proposed. Finally, variations in the amount of dissolved oxygen in the liquid were measured to analyze the mass transfer characteristics. The increase in nozzle inner diameter and gas flow rate both promoted mass transfer, but the increased liquid viscosity hindered mass transfer.

Investigation of a Complex Reaction Pathway Network of Isobutane/2-Butene Alkylation by CGC-FID and CGC-MS-DS.

The mechanism of reaction in isobutane/2-butene alkylation systems is extremely complicated, accompanied by numerous side reactions. Therefore, a comprehensive understanding of the reaction pathways in this system is essential for an in-depth discussion of the reaction mechanism and for improving the selectivity of the major products (clean fuel blend components). The alkylation of isobutane/2-butene was studied using a self-made intermittent reaction device with a metering, cooling, reaction, vacuum and analysis system. The alkylates were qualitatively and quantitatively analyzed using a capillary gas chromatography-mass spectrometry-data system (CGC-MS-DS) and capillary gas chromatography with flame ionization detection (CCGC-FID), respectively, and the precision and recovery of the quantitative analytical methods were verified. The results showed that the relative standard deviation (RSD) of the standard sample was below 0.78%, and the recoveries were from 98.53% to 102.85%. Under the specified reaction conditions, 79 volatile substances were identified from the alkylates, and the selectivity of C8 and trimethylpentanes (TMPs) reached 63.63% and 53.81%, respectively. The changes of the main chemical components in the alkylation reaction with time were tracked and analyzed, based on which reaction pathways were determined, and a complex reaction network containing the main products' and the by-products' generation pathway was constructed.

Measurement and Prediction of Isothermal Vapor-Liquid Equilibrium and Thermodynamic Properties of a Turpentine + Rosin System Using the COSMO-RS Model.

The vapor-liquid equilibrium (VLE) of components of a turpentine + rosin system were measured at 313.2 and 333.2 K using headspace gas chromatography. The thermodynamic properties of the turpentine + rosin system such as activity coefficients, total pressure, partial pressure, excess Gibbs energies, and excess enthalpies were calculated using the COSMO-RS model. The results showed that the activity coefficients were greater than 1 for all components of turpentine except for longifolene, indicating a positive deviation from Raoult's law for all components of turpentine except for longifolene. The total pressures were about 1 kPa at 313.2 K and about 3 kPa at 333.2 K. Meanwhile, the excess Gibbs energies G E and excess enthalpies H E of the system were positive, indicating that the mixing of the components of turpentine and rosin was endothermic. Moreover, the hydrogen bonding interaction energy H E(hydrogen bonding) contributed the most for the excess enthalpies H E.

Experimental Determination and Computational Prediction of Dehydroabietic Acid Solubility in (-)-α-Pinene + (-)-ß-Caryophyllene + P-Cymene System.

The solubility of dehydroabietic acid in (-)-α-pinene, p-cymene, (-)-ß-caryophyllene, (-)-α-pinene + p-cymene, (-)-ß-caryophyllene + p-cymene and (-)-α-pinene + (-)-ß-caryophyllene were determined using the laser monitoring method at atmospheric pressure. The solubility of dehydroabietic acid was positively correlated with temperature from 295.15 to 339.46 K. (-)-α-pinene, p-cymene, and (-)-ß-caryophyllene were found to be suitable for the solubilization of dehydroabietic acid. In addition, the non-random two liquid (NRTL), universal quasi-chemical (UNIQUAC), modified Apelblat, modified Wilson, modified Wilson-van't Hoff, and λh models were applied to correlate the determined solubility data. The modified Apelblat model gave the minor deviation for dehydroabietic acid in monosolvents, while the λh equation showed the best result in the binary solvents. A comparative analysis of compatibility between solutes and solvents was carried out using Hansen solubility parameters. The thermodynamic functions of ΔsolH0, ΔsolS0, ΔsolG0 were calculated according to the van't Hoff equation, indicating that the dissolution was an entropy-driven heat absorption process. The Conductor-like Screening Model for Real Solvents (COSMO-RS) combined with an experimental value was applied to predict the reasonable solubility data of dehydroabietic acid in the selected solvents systems. The interaction energy of the dehydroabietic acid with the solvent was analyzed by COSMO-RS.

Synergistic Effect of Ni/W/Cu on MgAl2O4 for One-Pot Hydrogenolysis of Cellulose to Ethylene Glycol at a Low H2 Pressure.

Nickel and tungsten, combined with copper, were incorporated into a magnesium aluminum spinel to form a multifunctional catalyst (Ni-W-Cu/MgAl2O4). Characterization results suggested that the adjacent Cu not only facilitated the reduction of W6+ to W5+ with substantial oxygen vacancies but also promoted the reducibility of the Ni species. Besides, the incorporation of Ni, W, and Cu into the support enhanced the catalytic acidity, as well as the L acid sites. The catalyst exhibited a strong synergistic effect between the three metals and the support, resulting in higher catalytic activity for the one-pot hydrogenolysis of cellulose to ethylene glycol. High cellulose conversion (100%) and ethylene glycol yield (52.8%) were obtained, even under a low H2 pressure of 3 MPa.

Joule-Thomson Effect on a CCS-Relevant (CO2 + N2) System.

The Joule-Thomson effect is a key chemical thermodynamic property that is encountered in several industrial applications for CO2 capture and storage (CCS). An apparatus was designed and built for determining the Joule-Thomson effect. The accuracy of the device was verified by comparing the experimental data with the literature on nitrogen and carbon dioxide. New Joule-Thomson coefficient (µJT) measurements for three binary mixtures of (CO2 + N2) with molar compositions x N2 = (0.05, 0.10, 0.50) were performed in the temperature range between 298.15 and 423.15 K and at pressures up to 14 MPa. Three equations of state (GERG-2008 equation, AGA8-92DC, and the Peng-Robinson) were used to calculate the µJT compared with the corresponding experimental data. All of the equations studied here except PR have shown good prediction of µJT for (CO2 + N2) mixtures. The relative deviations with respect to experimental data for all (CO2 + N2) mixtures from the GERG-2008 were within the ±2.5% band, and the AGA8-DC92 EoSs were within ±3%. The Joule-Thomson inversion curve (JTIC) has also been modeled by the aforementioned EoSs, and a comparison was made between the calculated JTICs and the available literature data. The GERG-2008 and AGA8-92DC EoSs show good agreement in predicting the JTIC for pure CO2 and N2. The PR equation only matches well with the JTIC for pure N2, while it gives a poor prediction for pure CO2. For the (CO2 + N2) mixtures, the three equations all give similar results throughout the full span of JTICs. The temperature and pressure of the transportation and compression conditions in CCS are far lower than the corresponding predicted P inv,max and T inv,max for (CO2 + N2) mixtures.

Rationally Constructing A Nano MOF-Derived Ni and CQD Embedded N-Doped Carbon Nanosphere for the Hydrogenation of Petroleum Resin at Low Temperature.

A key issue in attaining highly efficient supported catalysts for the hydrogenation of unsaturated polymers arises from the entanglement between the number of exposed active sites and the severe internal mass transfer limitation caused by their large molecular size. Hence, an ultrasmall N-doped carbon nanosphere with Ni NPs and CQDs embedded (Ni-CQDs/NCNs) was reasonably constructed by low-temperature (400 °C) pyrolysis of the precursor CQDs@Nano-Ni-ZIFs. As-prepared Ni-CQDs/NCNs exhibited superior catalytic activity to a commercial 10% Pd/C catalyst in petroleum resin hydrogenation under a low temperature of 150 °C, which is 100 and 60 °C lower than that of previously reported Ni- and Pd-based catalysts, respectively. The excellent catalytic activity of Ni-CQDs/NCNs mainly contributes to the following factors: first, its ultrasmall structure (ca. 50 nm) eliminates the internal mass transfer limitation; second, the CQDs and N-doped carbon matrix stabilize the 53.1 wt % high-loading Ni NPs at a small size of 5.6 nm, providing abundant active sites; and third, the electronic regulation of N-doped carbon enhances the intrinsic activity of Ni, which was revealed by the experiments and DFT calculations. Besides, Ni-CQDs/NCNs exhibits long-term stability and appreciable magnetic separation performance, making it a considerable candidate for industrial application. This work not only offers a facile approach to prepare nano MOF-derived catalysts but also gives helpful instruction to the rational design of heterogeneous catalysts for the reaction involving large molecules.

C9 Petroleum Resin Hydrogenation over a PEG1000-Modified Nickel Catalyst Supported on a Recyclable Fluid Catalytic Cracking Catalyst Residue.

A PEG1000-modified nickel-based catalyst (Ni-PEG1000/FC3R) supported on an activated fluid catalytic cracking catalyst residue (FC3R) was synthesized and applied to C9 petroleum resin (C9PR) hydrogenation. The results of the Brunauer-Emmett-Teller method, X-ray diffraction, H2 temperature-programmed reduction, and scanning electron microscopy-energy-dispersive X-ray spectroscopy show that the Ni-PEG1000/FC3R catalyst had a smaller crystallite size and higher Ni dispersion than those of a Ni/FC3R catalyst. The prepared Ni-PEG1000/FC3R catalyst was applied in a hydrogenation of C9PR at 270 °C and 6 MPa H2 pressure for 3 h. Under these conditions, the bromine value of C9PR was decreased from 46.1 g Br/100 g (Gardner color grade no. 11) to 0.72 g Br/100 g (Gardner color grade no. 1), and the sulfur content was reduced from 25.7 to 1.66 mg kg-1. Experimental results show that the Ni-PEG1000/FC3R catalyst exhibited high activity and stability for C9PR hydrogenation.

The Emulsifying Properties of Hydrogenated Rosin Xylitol Ester as a Biomass Surfactant for Food: Effect of pH and Salts.

The xylitol ester of hydrogenated rosin (XEHR) was obtained for the first time from biomass-based hydrogenated rosin and xylitol using an environmentally friendly, high-pressure CO2 catalytic synthesis. This compound is intended for use as an emulsifier for food. Analyses by ICP-AES showed the absence of heavy metal residues in the product, such that it met food standards. Fourier transform infrared and nuclear magnetic resonance spectroscopies together with gel permeation chromatography confirmed the successful esterification and the formation of a monoester and diester with molar masses of 427 and 772 g/mol. The emulsification of water/soybean oil mixtures by adding the XEHR was assessed at pH values of 4, 6.86, and 10 and in the presence of NaCl, KCl, MgCl2, and CaCl2. The XEHR was found to act as an emulsifier by reducing the interfacial tension of such mixtures to less than 2 mN/m under all conditions. The highest emulsifying activity index (9.52 m2/g) and emulsifying stability index (94.53%) were obtained after adding MgCl2 (100 mM). Particle size and confocal microscopy showed that the presence of salts gave a more uniform droplet size and a finer emulsion structure. The high viscosities of the emulsions containing salts also suggested a more cohesive oil droplet network.

Synthesis, characterization and activity performance of nickel-loaded spent FCC catalyst for pine gum hydrogenation.

A Ni-based catalyst supported over a spent fluid catalytic cracking (FCC) catalyst was prepared by a wet impregnation method. The catalytic characteristic was investigated in pine gum hydrogenation. Optimum conditions for catalyst preparation were obtained as: 15% Ni loading, 723 K calcination temperature, and 723 K reduction temperature for 2.5 h. The characterization results indicate that the specific surface area of the spent catalyst increased from 65.70 m2 g-1 to 67.78 m2 g-1 after calcination. The H2-TPR profile of the spent FCC catalyst exhibited two reduction peaks at 1123 °C and 670 °C. The TG curves showed that the second and third steps occur at 440 K and 550 K, respectively, having a total weight loss of 16%. The NiO grains possess rhombus particles on the surface or between the layers of the supported NiO catalyst. After activation in H2 flow, the metallic Ni loads on the support with no covalent bond between them. The NH3-TPD results indicated that the spent FCC catalyst held an obvious distribution of weakly acidic sites, and the acid sites became stronger after loading the catalyst with Ni. The hydrogenation products of pine gum were identified by GC-MS and a reaction mechanism was proposed. This study demonstrated its cost-effectiveness, environment-friendly nature and that the utilization of a spent FCC catalyst can be effectively applied as an alternative approach to pine gum hydrogenation on an industrial level.

A novel acid catalyst based on super/subcritical CO2-enriched water for the efficient esterification of rosin.

Rosin esters are widely applied as masticatory substances and beverage stabilizers, while classical acid-catalysed processes will lead to metal residue or environmental issues. Super/subcritical CO2-enriched high temperature liquid water (HTLW) as a green acid catalyst in the esterification reaction of rosin with glycerol was investigated. The pH of CO2-H2O binary system, as calculated based on gas-liquid equilibrium, charge balance and chemical equilibrium equations, ranged from 3.49 to 3.70 depending on the reaction conditions, indicating effective acid catalysis. Response surface methodology experiments showed the optimum conditions were 3.5 h, 3.9 MPa CO2 pressure, a rosin-to-glycerol molar ratio of 1.32 and 269°C, and an enhanced esterification yield of 94.74% was achieved, which was superior to that obtained using a ZnO catalyst. It was found that the esterification kinetics was a pseudo first-order reaction, and the enthalpy and entropy of activation were calculated using the Arrhenius-Polanyi equation. The presence of super/subcritical CO2-enriched HTLW catalyst can decrease the activation energy and significantly accelerate the reaction rate.

A Ni-based catalyst with polyvinyl pyrrolidone as a dispersant supported in a pretreated fluid catalytic cracking catalyst residue for C9 petroleum resin (C9 PR) hydrogenation.

A Ni-based catalyst (Ni-PVP/PFC3R) with polyvinyl pyrrolidone (PVP) as a dispersant supported in a pretreated fluid catalytic cracking catalyst residue (PFC3R) was synthesized and applied to C9 petroleum resin (C9 PR) hydrogenation. For comparison, a Ni catalyst without PVP (Ni/PFC3R) was prepared in the same way. Ni-PVP/PFC3R exhibited higher activity and better stability. The catalysts were characterized by X-ray diffraction, scanning electron microscope, H2-temperature programmed reduction/temperature programmed desorption, Fourier transform infrared spectroscopy and the Brunauer-Emmett-Teller method. The catalysts had a smaller crystallite size and stronger interactions between the Ni species and the PFC3R support in the presence of PVP. The effects of nickel loading, H2 pressure, temperature and reaction time for C9 PR hydrogenation over Ni-PVP/PFC3R were investigated. The bromine number was reduced to 1.25 under the following conditions: nickel content of 12 wt%, PVP amount of 1.5 wt%, temperature of 270°C, H2 pressure of 8 MPa and reaction time of 240 min.

Catalytic methyl esterification of colophony over ZnO/SFCCR with subcritical CO2: catalytic performance, reaction pathway and kinetics.

A heterogeneous catalyst (ZnO/SFCCR) composed of ZnO supported on spent fluid cracking catalyst by wet impregnation was synthesized and applied to the esterification of colophony acids with methanol under subcritical CO2 conditions. The catalyst was characterized by SEM-EDS, BET, ICP, FTIR, XRD and Py-IR. An experimental set-up involving a new injection technique was designed to promote the heterogeneous methyl esterification, and the subcritical CO2 played a role in auxiliary acid catalysis (a pH range of 3.54-3.91), increasing the lifespan of ZnO/SFCCR, reducing the viscosity of the system to promote gas-liquid mass transfer. A maximum conversion rate of 97.01% was obtained in a relatively short time of 5 h. Kinetic experiments were performed from 190 to 220°C using a special high-temperature sampling device and analysing aliquots with high-performance liquid chromatography. A new reaction pathway, involving methyl abietate, methyl dehydroabietate, methyl neoabietate and methyl palustrate along with other kinds of colophony acids, was developed. The kinetic parameters were obtained using the Levenberg-Marquardt nonlinear least-squares method, and the activation energies for the isomerizations of neoabietic and palustric acids and for the methyl esterification of neoabietic, abietic, palustric and dehydroabietic acids were found to be 107.09, 113.95, 68.99, 49.85, 75.43 and 59.20 kJ mol-1, respectively. The results from the kinetic model were in good agreement with experimental values.

Inactivation of HMGCL promotes proliferation and metastasis of nasopharyngeal carcinoma by suppressing oxidative stress.

Altered metabolism is considered as a hallmark of cancer. Here we investigated expression of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) 2 lyase (HMGCL), an essential enzyme in ketogenesis, which produces ketone bodies by the breakdown of fatty acids to supply energy, in nasopharyngeal carcinoma (NPC). The expression of HMGCL was silenced in NPC tissue. Downregulation of HMGCL in NPC was associated with low intracellular ß-hydroxybutyrate (ß-HB) production, thereby reducing reactive oxygen species (ROS) generation. Ectopic expression of HMGCL restored ß-HB level, associated with suppressed proliferation and colony formation of NPC cells in vitro and decreased tumorigenicity in vivo. HMGCL suppressed the migration and invasion of NPC cells in vitro via mesenchymal-epithelial transition. Furthermore, extracellular ß-HB supply suppressed the proliferation and migration of NPC cells. Both intra- and extracellular ß-HB exerting a suppressive role in NPC depends on ROS generation. Ketogenesis may be impaired in NPC cells due to lack of HMGCL expression, suggesting that it may be a promising target in NPC therapy.

Epstein-Barr virus-encoded LMP2A stimulates migration of nasopharyngeal carcinoma cells via the EGFR/Ca2+/calpain/ITGß4 axis.

Epstein-Barr virus (EBV)-encoded latent membrane protein 2A (LMP2A) promotes the motility of nasopharyngeal carcinoma (NPC) cells. Previously, we have shown that the localization of integrin ß4 (ITGß4) is regulated by LMP2A, with ITGß4 concentrated at the cellular protrusions in LMP2A-expressing NPC cells. In the present study, we aim to further investigate mechanisms involved in this process and its contribution to cell motility. We show that expression of LMP2A was correlated with increased epidermal growth factor receptor (EGFR) activation, elevated levels of intracellular Ca2+, calpain activation and accelerated cleavage of ITGß4. Activation of EGFR and calpain activity was responsible for a redistribution of ITGß4 from the basal layer of NPC cells to peripheral membrane structures, which correlated with an increased migratory capacity of NPC cells. Furthermore, we demonstrated that the calpain inhibitor calpastatin was downregulated in NPC primary tumors. In conclusion, our results point to LMP2A-mediated targeting of the EGFR/Ca2+/calpain/ITGß4 signaling system as a mechanism underlying the increased motility of NPC cells. We suggest that calpain-facilitated cleavage of ITGß4 contributes to the malignant phenotype of NPC cells.

Subcritical carbon dioxide-water hydrolysis of sugarcane bagasse pith for reducing sugars production.

The aim of present study was to obtain total reducing sugars (TRS) by hydrolysis in subcritical CO2-water from sugarcane bagasse pith (SCBP), the fibrous residue remaining after papermaking from sugarcane bagasse. The optimum hydrolysis conditions were evaluated by L16(45) orthogonal experiments. The TRS yield achieved 45.8% at the optimal conditions: 200°C, 40min, 500rmin-1, CO2 initial pressure of 1MPa and liquid-to-solid ratio of 50:1. Fourier transform infrared spectrometry and two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance were used to characterize hydrolysis liquor, treated and untreated SCBP, resulting in the removal of hemicelluloses to mainly produce xylose, glucose and arabinose during hydrolysis. The severity factors had no correlation to TRS yield, indicating that the simple kinetic processes of biomass solubilisation cannot perfectly describe the SCBP hydrolysis. The first-order kinetic model based on consecutive reaction was used to obtain rate constants, activation energies and pre-exponential factors.

Methylation of S100A8 is a promising diagnosis and prognostic marker in hepatocellular carcinoma.

The abnormality of DNA methylation is one of the major epigenetic alterations in the human hepatocellular carcinoma (HCC). We have assessed the global genomic DNA methylation profiles in human HCC patients by using the Infinium Human Methylation27 BeadChip. A CpG loci of S100A8 was found to be significantly hypomethylated in HCC.Pooled meta-analysis of five validation public datasets demonstrated its methylation level was significantly lower for HCC compared to paired adjacent normal tissues. Quantitative pyrosequencing analysis also showed that the S100A8 methylation level was decreased in cancer tissues (31.90%±13.31%) than that in the paired adjacent normal tissues (65.33%±3.64%, p<0.01). The area under the ROC curve (AUC) value was 0.950 (p<0.01). Kaplan-Meier survival curves revealed that hypomethylation of S100A8 was associated with shortened overall survival (OS) and progression-free survival (PFS) (log rank p<0.05). Multivariate Cox proportional hazards model also indicated significantly shorter OS (HR, 1.709; 95 % CI, 1.127-2.591) and PFS (HR, 1.767; 95 % CI, 1.168-2.974) were observed in the low-methylation-level group compared to the high-methylation-level group. Furthermore, S100A8 overexpression in Huh7 and MHCC-97H hepatoma cell lines led to increased cell proliferation, migration, invasion, and tumor growth. These findings suggested S100A8 methylation to be served as potential diagnosis and prognosis marker for HCC. S100A8 also may play as a tumor promoter in HCC.