Time filter

Source Type

Zhao L.,Guangxi University for Nationalities | Zhao L.,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products | Liu Z.,Guangxi University for Nationalities | Liu Z.,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products
Advanced Materials Research | Year: 2013

Rosin-modified lignosulfonates were prepared according to the following procedure: firstly, sulfomethylation of kraft lignin; secondly, preparation of 2,3-epoxypropyl ester of rosin; thirdly, preparation of modified-rosin lignosulfonates via etherification of sulfomethylated lignin with 2,3-epoxy propyl ester of rosin. Experimental results show that the optimum conditions for synthesis of 2,3-epoxy propyl ester of rosin are as follows: molar ratio for n(rosin): n (epichlorohydrin): n (NaOH) is1:6:1, reaction temperature is 100 °C (for rosin ester) and 75 °C (for 2,3-epoxypropyl ester of rosin, the same below), reaction time is 5.5 h and 3 h respectively. When molar ratio of lignosulfonate to 2,3-epoxypropylester of rosin is 1/5, rosin-modified lignosulfonates were prepared at 55 °C for 4.5 h with pH 11.5. Hydrophilic sulfonic group and the lipophilic adbietic group were incorporated into the molecular structure of kraft lignin via corresponding reactions. The surface tension of 10 g/L aqueous solution of rosin-modified lignosulfonate is 49.3 mN/m. © (2013) Trans Tech Publications, Switzerland.


Yu H.-L.,Beijing Forestry University | Tang Y.,Beijing Forestry University | Tang Y.,GuangXi Key Laboratory of Chemistry and Engineering of Forest Products | Xing Y.,Beijing Forestry University | And 3 more authors.
Bioresource Technology | Year: 2013

A potential commercial pretreatment for furfural residues (FRs) was investigated by using a combination of green liquor and hydrogen peroxide (GL-H2O2). The results showed that 56.2% of lignin removal was achieved when the sample was treated with 0.6g H2O2/g-DS (dry substrate) and 6mL GL/g-DS at 80°C for 3h. After 96h hydrolysis with 18FPU/g-cellulose for cellulase, 27CBU/g-cellulose for β-glucosidase, the glucose yield increased from 71.2% to 83.6%. Ethylenediaminetetraacetic acid was used to reduce the degradation of H2O2, the glucose yield increased to 90.4% after the addition of 1% (w/w). The untreated FRs could bind more easily to cellulase than pretreated FRs could. The structural changes on the surface of sample were characterized by X-ray photoelectron spectroscopy. The results indicated that the surface lignin could be effectively removed during pretreatment, thereby decreasing the enzyme-lignin binding activity. Moreover, the carbonyl from lignin plays an important role in cellulase binding. © 2013 Elsevier Ltd.


Yu H.,Beijing Forestry University | Xing Y.,Beijing Forestry University | Lei F.,GuangXi Key Laboratory of Chemistry and Engineering of Forest Products | Liu Z.,Chunlei Industrial Group Company | And 2 more authors.
Bioresource Technology | Year: 2014

Furfural residues (FRs) were pretreated with ethanol and a green liquor (GL) catalyst to produce fermentable sugar. Anthraquinone (AQ) was used as an auxiliary reagent to improve delignification and reduce cellulose decomposition. The results showed that 42.7% of lignin was removed and 96.5% of cellulose was recovered from substrates pretreated with 1.0. mL. GL/g of dry substrate and 0.4% (w/w) AQ at 140. °C for 1. h. Compared with raw material, ethanol-GL pretreatment of FRs increased the glucose yield from 69.0% to 85.9% after 96. h hydrolysis with 18. FPU/g-cellulose for cellulase, 27. CBU/g-cellulose for β-glucosidase. The Brauner-Emmett-Teller surface area was reduced during pretreatment, which did not inhibit the enzymatic hydrolysis. Owing to the reduced surface area, the unproductive binding of cellulase to lignin was decreased, thus improving the enzymatic hydrolysis. The degree of polymerization of cellulose from FRs was too low to be a key factor for improving enzymatic hydrolysis. © 2014 Elsevier Ltd.


Lin G.-S.,Guangxi University | Ma C.-H.,Guangxi University | Duan W.-G.,Guangxi University | Cen B.,Guangxi University | And 2 more authors.
Holzforschung | Year: 2014

This work is aiming at the preparation of new bioactive compounds from a-pinene as starting material. To this purpose, the intermediates (disubstituted phenyl acylamino thioureas, class G) were cyclized to dithiadiazoles (class H). The intermediates and target compounds were analyzed by Fourier transform infrared, 1H nuclear magnetic resonance (NMR), 13C NMR, and electrospray ionization-mass spectrometry and elemental analysis. The bioassay experiments showed that the compounds G and H have herbicidal, fungicidal, and plant growth-regulating activities. The compounds 2,2'-dimethylphenyl thiadiazole and 3,3'-dimethylphenyl thiadiazole exhibited a growth inhibition activity of 72% and 68% against the root of rape (Brassica campestris L.) at a concentration of 100 μg ml-1 (60-79% inhibition level). The compound 4,4'-dichlorophenyl acylamino thiourea displayed an inhibition activity of 75% against Physalospora piricola at a concentration level of 50 μg ml-1 (60-79% inhibition level). © 2014 Walter de Gruyter GmbH, Berlin/Boston.


Tang Y.,Beijing Forestry University | Tang Y.,GuangXi Key Laboratory of Chemistry and Engineering of Forest Products | Lei F.,GuangXi Key Laboratory of Chemistry and Engineering of Forest Products | Cristhian C.,Lund University | And 3 more authors.
BMC Biotechnology | Year: 2014

Background: Enhancement of enzymatic digestibility by some supplementations could reduce enzyme loading and cost, which is still too high to realize economical production of lignocellulosic biofuels. A recent study indicates that yeast hydrolysates (YH) have improved the efficiency of cellulases on digestibility of furfural residues (FR). In the current work, the components of YH were separated by centrifugation and size exclusion chromatography and finally characterized in order to better understand this positive effect.Results: A 60.8% of nitrogen of yeast cells was remained in the slurry (YHS) after hydrothermal treatment. In the supernatant of YH (YHL), substances of high molecular weight were identified as proteins and other UV-absorbing compounds, which showed close molecular weight to components of cellulases. Those substances attributed to a synergetic positive effect on enzymatic hydrolysis of FR. The fraction of YHL ranged from 1.19 to 2.19 mL (elution volume) contained over 50% of proteins in YHL and had the best performance in stimulating the release of glucose. Experiment results proved the adsorption of proteins in YHL on lignin.Conclusions: Supplementation of cellulases with YH enhances enzymatic digestibility of FR mainly by a competitive adsorption of non-enzymatic substances on lignin. The molecular weight of these substances has a significant impact on their performance. Different strategies can be used for a good utilization of yeast cells in terms of biorefinery concept. © 2014 Tang et al.; licensee BioMed Central Ltd.


Tang L.,Fujian Agriculture and forestry University | Li T.,Fujian Agriculture and forestry University | Zhuang S.,Fujian Agriculture and forestry University | Lu Q.,Fujian Agriculture and forestry University | And 2 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2016

Fluorescent labeled nanoparticles are expected to have potential applications in biological and imaging systems. In this study, in order to construct the fluorescent nanoparticles for pH-sensing, l-leucine amino acid is used as a spacer linker between cellulose nanocrystals (CNCs) and a pH-indicator dye (5 (and 6)-carboxy-2′,7′-dichlorofluorescein, CDCF). Characterization by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) is adopted to follow the chemical modification, whereas the morphology is determined by atomic force microscopy (AFM). The crystallinity determined by NMR for the CNCs, A-CNCs, and F-A-CNCs is 78.32, 79.84, and 79.52, respectively. The quantitative analysis by elemental analysis revealed that the degree of cellulose hydroxyl group substitution (DS) of A-CNCs and F-A-CNCs is 0.05 and 0.27, respectively. According to the obtained results, CDCF fluorescein could be successfully labeled onto CNCs via l-leucine amino acid spacer linking, and the cellulose structure is stable during the labeling reaction. The fluorescent properties of the yielding pH-sensitive fluorescent CNCs (F-A-CNCs) are characterized by fluorescence spectrometer and imaged by confocal laser scanning microscopy (CLSM). The result shows that the fluorescence intensity of F-A-CNCs increases with increasing pH of the buffer from 2.28 to 10.84. © 2016 American Chemical Society.


PubMed | Beijing Forestry University, GuangXi Key Laboratory of Chemistry and Engineering of Forest Products and Chunlei Industrial Group Company
Type: | Journal: Bioresource technology | Year: 2014

Furfural residues (FRs) were pretreated with ethanol and a green liquor (GL) catalyst to produce fermentable sugar. Anthraquinone (AQ) was used as an auxiliary reagent to improve delignification and reduce cellulose decomposition. The results showed that 42.7% of lignin was removed and 96.5% of cellulose was recovered from substrates pretreated with 1.0 mL GL/g of dry substrate and 0.4% (w/w) AQ at 140C for 1h. Compared with raw material, ethanol-GL pretreatment of FRs increased the glucose yield from 69.0% to 85.9% after 96 h hydrolysis with 18 FPU/g-cellulose for cellulase, 27 CBU/g-cellulose for -glucosidase. The Brauner-Emmett-Teller surface area was reduced during pretreatment, which did not inhibit the enzymatic hydrolysis. Owing to the reduced surface area, the unproductive binding of cellulase to lignin was decreased, thus improving the enzymatic hydrolysis. The degree of polymerization of cellulose from FRs was too low to be a key factor for improving enzymatic hydrolysis.


Yu H.,Beijing Forestry University | You Y.,Beijing Forestry University | Lei F.,GuangXi Key Laboratory of Chemistry and Engineering of Forest Products | Liu Z.,GuangXi Key Laboratory of Chemistry and Engineering of Forest Products | And 2 more authors.
Bioresource Technology | Year: 2015

Green liquor (GL) combined with H2O2 (GL-H2O2) and green liquor (GL) combined with ethanol (GL-ethanol) were chosen for treating sugarcane bagasse. Results showed that the glucose yield (calculated from the glucose content as a percentage of the theoretical glucose available in the substrates)of sugarcane bagasse from GL-ethanol pretreatment (97.7%) was higher than that from GL-H2O2 pretreatment (41.7%) after 72h hydrolysis with 18 filter paper unit (FPU)/g-cellulose for cellulase, 27,175 cellobiase units (CBU)/g-cellulose for β-glucosidase. Furthermore, about 94.1% of xylan was converted to xylose after GL-ethanol pretreatment without additional xylanase, while the xylose yield was only 29.2% after GL-H2O2 pretreatment. Scanning electron microscopy showed that GL-ethanol pretreatment could break up the fiber severely. Moreover, GL-ethanol pretreated substrate was more accessible to cellulase and more hydrophilic than that of GL-H2O2 pretreated. Therefore, GL-ethanol pretreatment is a promising method for improving the overall sugar (glucose and xylan) yield of sugarcane bagasse. © 2015 Published by Elsevier Ltd.


PubMed | Guangxi Key Laboratory of Chemistry and Engineering of Forest Products and Guangxi University
Type: Journal Article | Journal: Molecules (Basel, Switzerland) | Year: 2017

A series of novel myrtenal derivatives bearing 1,2,4-triazole moiety were designed and synthesized by multi-step reactions in an attempt to develop potent antifungal agents. Their structures were confirmed by using UV-vis, FTIR, NMR, and ESI-MS analysis. Antifungal activity of the target compounds was preliminarily evaluated by the in vitro method against


PubMed | Beijing Forestry University, GuangXi Key Laboratory of Chemistry and Engineering of Forest Products and Nanjing Institute for the Comprehensive Utilization of Wild Plant
Type: | Journal: Bioresource technology | Year: 2015

Green liquor (GL) combined with H2O2 (GL-H2O2) and green liquor (GL) combined with ethanol (GL-ethanol) were chosen for treating sugarcane bagasse. Results showed that the glucose yield (calculated from the glucose content as a percentage of the theoretical glucose available in the substrates)of sugarcane bagasse from GL-ethanol pretreatment (97.7%) was higher than that from GL-H2O2 pretreatment (41.7%) after 72h hydrolysis with 18 filter paper unit (FPU)/g-cellulose for cellulase, 27,175 cellobiase units (CBU)/g-cellulose for -glucosidase. Furthermore, about 94.1% of xylan was converted to xylose after GL-ethanol pretreatment without additional xylanase, while the xylose yield was only 29.2% after GL-H2O2 pretreatment. Scanning electron microscopy showed that GL-ethanol pretreatment could break up the fiber severely. Moreover, GL-ethanol pretreated substrate was more accessible to cellulase and more hydrophilic than that of GL-H2O2 pretreated. Therefore, GL-ethanol pretreatment is a promising method for improving the overall sugar (glucose and xylan) yield of sugarcane bagasse.

Loading Guangxi Key Laboratory of Chemistry and Engineering of Forest Products collaborators
Loading Guangxi Key Laboratory of Chemistry and Engineering of Forest Products collaborators