Search

Peroxynitrite (ONOO-), a kind of reactive oxygen species, plays an indispensable role in many physiological processes. The stability and reactivity of ONOO- are significantly affected by the pH of the environment. A novel fluorescent probe RN-NA that can simultaneously respond to ONOO- and pH was proposed and constructed based on a rational-designed multifunctional fluorescence resonance energy transfer (FRET) platform. The RN-NA probe exhibited a remarkably different fluorescence change in response to ONOO- and pH. The fluorescence signals at 525 and 710 nm increased about 4-fold with a pH change from 8.0 to 3.0. The changes in fluorescence at 525 nm are mainly attributed to photo-induced electron transfer, and the fluorescence enhancement at 710 nm was mainly due to acid-induced open-closed circulation. In the presence of ONOO-, the fluorescence at 525 nm increased 5-fold, while the fluorescence at 710 nm was almost completely diminished. Up to 70-fold fluorescence enhancement was observed in the ratiometric channel F525/F710. In the cell imaging experiment, the intracellular pH was adjusted using H+/K+ ionophore and nigericin, and the endogenous ONOO- was generated by lipopolysaccharide (LPS) and γ-interferon (IFN-γ). The RN-NA probe can respond to cellular pH and endogenous ONOO- with remarkable fluorescence changes in both red/green and ratiometric channels.

Herein, efficient exploitation of biomass with diluted alkali-aided methanol organosolv treatment has been proposed. The ultrahigh glucose yield and high value-added lignin from xylose residue were...

In this study, alkaline catalyst (NaOH)-aided sulfolane organosolv pretreatment was firstly developed to reduce the recalcitrance of willow (Salix matsudana cv. Zhuliu) for effective saccharificatio...

One kind of molecular glass material was prepared via the epoxidation of eugenol and a subsequent thermochemical conversion process. This biobased molecular glass (ET-eugenol) shows high potential ...

Three nanocomposite catalysts such as Ru/graphene, WO3/graphene, and Ru–W18O49/graphene were synthesized by solvothermolysis to increase the ethylene glycol (EG) yield from the hydrothermal convers...

Lignocellulose is typically considered as one of the most promising feedstocks to produce a variety of renewable fuels and value-added chemicals. In this study, we developed an alternative valorization of lignocellulosic biomass toward multipurpose fractionation. Since the adopted pretreatment with a fully recyclable acid, p-TsOH, can significantly facilitate the degradation of hemicellulose, we initially converted hydrolysate into furfural with an average yield of 63.38% under the selected pretreatment condition. Next, a biomass-derived solvent, γ-valerolactone (GVL), was used to extract lignin from pretreated substrate, and a suggested pretreatment temperature 100 °C was proposed according to the characterization results from FTIR, 31P NMR, TGA, GPC, and 2D HSQC NMR. The obtained lignin, which exhibited excellent properties such as low molecular weight (Mw, 16053 g/mol), narrow polydispersities (Mw/Mn, 2.48), and high content of aliphatic OH (3.72 mmol/g), was easily upgraded to phenolic compounds by hy...

A two-step white rot–brown rot fungal pretreatment of corn cobs was proposed to enhance enzymatic hydrolysis efficiency while reducing the lengthy time requirement for the conventional fungal treatment process. Corn cobs were first pretreated by white rot fungi for 25 days, followed by short time brown rot fungi treated for 7 days. The results indicated that the enzymatic hydrolysis efficiency was dramatically improved as a result of the synergistic effects of combined pretreatments. The highest glucose yield of 83.0% was obtained by Trametes orientalis (Cui6300)–Fomitopsis pinicola (Cui12330) pretreatment. Chemical composition and FT-IR observations demonstrated that hemicelluloses were selectively degraded. Additionally, SEM analysis illustrated that the structural disruption of pretreated corn cobs occurred and might account for the enhancement of the hydrolysis efficiency. In this processing, 7 days of brown rot fungal treatment played a significant role in enzymatic hydrolysis enhancement. Cellulose ...

Upgrading corncob residues (CCR) to a high quality energy resource is an effective utilization of an underutilized industrial lignocellulose waste. A hydrothermal carbonization technique was therefore employed to generate a high heating value (HHV) hydrochar. Results showed that its HHV increased 47% after treatment at 230 °C for 1.5 h. Decreases in H/C and O/C verified that reductions in C and O reactions were occurring following hydrothermal carbonization. The chemical and thermal properties of the final hydrochar as analyzed by FT-IR, TG/DTG, and XRD analyses indicated that dehydration and decarboxylation were the predominant pathways for the C and O reductions. The present hydrothermal carbonization process is offered as a promising approach to upgrade CCR to a high heating value hydrochar under mild conditions.

The complicated structures of bagasse hinder the bioconversion processes for the production of bioenergy and biomaterials. In this study, an integrated process of hot-water extraction followed by high-boiling-solvent cooking (HBS, i.e., 1,4-butanediol) was demonstrated to fractionate bagasse into hemicellulose, lignin, and cellulose. The hot-water extraction resulted in the removal of hemicellulose, which facilitated the HBS cooking for the open fiber structure. As a result, 57–70% of lignin was isolated from the cooking spent liquor. Gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), 31P and 1H nuclear magnetic resonance (NMR), and thermogravimetry (TG) were employed for characterization of the organosolv lignin. Results showed that the organosolv lignin exhibited a chemical structure similar to enzymatic hydrolysis/mild acidolysis lignin (EMAL) but formed new phenolic OH groups (3–6-fold of EMAL). The high molecular weight and thermal stability would contribute to the p...

In this study, experimental viscosity results of hardwood prehydrolysis liquor (PHL) from the kraft-based dissolving pulp production process were obtained and used to develop empirical models describing the effect of temperature, solid content, the interaction between solute and solvent, and the concentration of lignin and hemicelluloses. The concentration, molar mass, and molecular weight of lignin and polysaccharide of PHL, all are the factors that affect the rheological behavior of the PHL. The results showed that, on the one side, Zaman and Fricke’s model gave better fitting when the viscosity is lower, on the other hand, a much better fitting of the Moosavifar’s model could be obtained by taking interaction between solute and solvent, solids content, concentration of lignin and hemicelluloses into account when the viscosity is higher, because of the interaction between solute lignin/hemicelluloses and solvent water, and the aggregation of lignin with itself, hemicelluloses with itself, and lignin wit...

Acid hydrolysis is an essential step in converting polysaccharides to monosaccharides for the production of fuels and chemicals. The prehydrolysis liquor (PHL) from the kraft-based dissolving pulp production process contains mainly oligosugars with a minor amount of monosugars. In this study, the influence of process conditions, including the sulfuric acid concentration, temperature, and time on the PHL hydrolysis was thoroughly investigated in order to get maximum monosugar concentration with minimal degradation of sugars. The maximum monosugar concentration was obtained at 130 °C for 20 min when the hydrolysis was carried out with 1.78% H2SO4. A high acid concentration (3.33%) increased furfural formation and decreased the monosugar concentration. Acetic acid is generated from the acetyl groups bound to the dissolved hemicelluloses, resulting in a significant increase in the acetic acid concentration in the PHL.