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28 February 2024, Volume 44 Issue 1 Previous Issue   
Preparation and Properties of Rosin-based Non-isocyanate Polyurethane
Bowen ZHANG, Yuemin ZHOU, He LIU, Shiwei LIU, Shibin SHANG, Zhanqian SONG
2024, 44 (1):  1-8.  doi: 10.3969/j.issn.0253-2417.2024.01.001
Abstract ( 103 )   HTML ( 9 )   PDF (2696KB) ( 112 )  

Acrylpimaric acid diglycidyl ether(AE) was synthesized from acrylpimaric acid(APA), a rosin derivative, and acrylpimaric acid cyclocarbonate(AC) was further prepared. Then the rosin-based non-isocyanate polyurethane(ACPP) film materials was prepared by the reaction of the cyclic carbonate groups of AC with the amino group in polyethylenimine(PEI) and the polyester polyamine(Priamine 1074). The structure and properties of ACPP materials were characterized by Fourier transform infrared spectroscopy(FT-IR), thermogravimetric(TG), dynamic thermomechanical analysis(DMA) and other techniques. The results showed that with the increase of AC content, the introduction of rigid structure of hydrogenated phenanthrene ring in the rosin structure increased, resulting in the enhancement of the mechanical properties of ACPP. The tensile strength of the material (ACPP1) could reach 15 MPa when the amino/cyclocarbonate group molar ratio value was 1. At the same time, the glass transition temperature(Tg) of ACPP material increased significantly, which were greater than 40 ℃. When the molar ratio of amino group to cyclocarbonate group was 0.8, the Tg of ACPP0.8 reached the maximum value of 49.4 ℃. The results of self-healing performance test showed that the scratch healing of ACPP1 material with scratch could be achieved after 1 h heating at the condition of 160 ℃ and 5 MPa, and the healing rate was up to 100%. In addition, after physical reprocessing and chemical recovery and reprocessing, the mechanical properties of ACPP1 materials could still be restored to 85% of the original strength, showing excellent recovery and reprocessing performance.

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Preparation and Characterization of Enzyme/Magnetic-driven Pectin/Sodium Alginate Composite Microsphere
Lingling KANG, Guifang LI, Xianliang SONG, Jing HE, Jiandu LEI
2024, 44 (1):  9-16.  doi: 10.3969/j.issn.0253-2417.2024.01.002
Abstract ( 65 )   HTML ( 2 )   PDF (11244KB) ( 80 )  

This study designed and constructed an enzyme/magnetic dual-driven pectin(PET)/sodium alginate(SA) composite microsphere robot drug delivery system. Specifically, through the dropwise method, calcium lactate was used as a crosslinking agent to simultaneously load Fe3[KG-*6]O4 magnetic nanoparticles(Mag), catalase(CAT)/glucose oxidase(GOD)/zinc phosphate hybrid particles, and a natural camptothecin derivative(irinotecan hydrochloride CPT-11) drug into PET/SA composite microspheres, by which fabricated the magnetically responsive PET/SA composite microspheres(CPT-11/CAT/GOD-Zn3(PO4)2@Mag/PET-SA). The effects of different compounding ratios of PET to SA and the addition of magnetic particles on the structure, morphology, particle size, and drug encapsulation efficiency of the composite microspheres were investigated. The drug release curves of the drug-loaded microsphere robots in simulated gastric fluid(SGF, pH value 1.2) and simulated intestinal fluid(SIF, pH value 6.8) were determined by ultraviolet spectrometry method. The results showed that the prepared enzyme/magnetic dual-driven microsphere drug-loading robot had good sphericity, but the addition of magnetic particles caused the appearance of a lot of wrinkles and become rough on the surface of the composite microspheres, leading to a significant decrease in drug encapsulation rate. When the ratio of m(PET) to m(SA) was 1∶3, the average particle size of the composite microspheres before the addition of magnetic particles was 1.658 mm, with an encapsulation rate of 63.1%. After the addition of magnetic particles, the average particle size of the composite microspheres increased up to 1.885 mm, and the encapsulation rate decreased up to 47.7%. The release of irinotecan hydrochloride drug was relatively slow in SGF while it released rapidly in SIF. Vibrating sample magnetometer(VSM) tests indicated that the composite microspheres exhibited superparamagnetism and high magnetization intensity, and could undergo self-driven in a glucose solution.

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The Separation of Ginkgo Kraft Lignin Components and Its Anti-tumor Structure-activity
Yimin XIE, Yuanyuan YUE, Yunbo ZHAO, Xin WEI
2024, 44 (1):  17-23.  doi: 10.3969/j.issn.0253-2417.2024.01.003
Abstract ( 56 )   HTML ( 1 )   PDF (608KB) ( 73 )  

To isolate anticancer substance from Kraft lignin, ginkgo Kraft lignin(KL) was fractionated with different polar solvents, and the anticancer activity of each fraction was studied by MTT method. The components with the most obvious inhibitory effect were purified by medium-pressure preparation liquid chromatography according to the results of anticancer activity determination. The structure of the compounds was determined by mass spectrometry and 13C NMR, and the structure-effect relationship was analyzed. The results of FT-IR spectra showed that ginkgo Kraft lignin had a similar structure to that of ginkgo milled wood lignin(MWL). The total phenol content(TPC) of the fractions decreased with the increase of their relative molecular mass. The results of anticancer activity showed that the ether soluble fraction(LC2) had a strongest inhibitory effect on human-derived lung cancer A549 cells with an IC50 of (366.09±6.39) mg/L. Further purification of LC2 revealed that the isolated compound L7 had the best anticancer activity, with an IC50 value of (89.44±2.13) mg/L against the lung cancer A549 cells. The results of mass spectrometric analysis and 13C NMR measurement indicated that compound L7 was a β-5 structure coniferyl aldehyde dimer with a 2-propionaldehyde substituent on the phenolic hydroxyl group. The increase of the aldehyde group on the side chain of the phenylpropane unit of the lignin fraction with small molecule could enhance the anticancer activity, while the increase of the ether bond would weaken the anticancer activity.

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Preparation and Properties of MMT/IFR Intumescent Flame Retardant Liquefied Sodium Lignosulfonate Based Polyurethane Foam
Xinyu AN, Xu LI, Ling GONG, Zhiming LIU
2024, 44 (1):  24-32.  doi: 10.3969/j.issn.0253-2417.2024.01.004
Abstract ( 64 )   HTML ( 1 )   PDF (4883KB) ( 83 )  

The liquefied sodium lignosulfonate(SLS) products were used to completely replace polyether polyols, the intumescent flame retardant(IFR) was composed of chitosan(CS) and ammonium polyphosphate(APP), and montmorillonite(MMT) were used as additives, which were employed to prepare MMT/IFR intumescent flame retardant/liquefied lignosulfonate based polyurethane foam(SLS-PUF/IFR/MMT). The flame retardancy, thermal stability, combustion performance, thermal conductivity and compression properties of the materials were analyzed by scanning electron microscope(SEM), limiting oxygen index(LOI), thermal gravimetric(TG) analyzer cone calorimeter, thermal conductivity tester and electronic universal testing machine. The results showed that: when the addition amount of IFR was 20%, the LOI value of the prepared material 100%SLS-PUF/20%IFR reached the highest value of 24.3%. When the amount of IFR was ≥16%, the vertical combustion grade of the prepared material 100%SLS-PUF/IFR reached Ⅴ-0 level. Basis on this result, the LOI value of the prepared material 100%SLS-PUF/20%IFR/2%MMT reached 24.8% and its vertical combustion grade could reach Ⅴ-0 level, when the addition of MMT was 2%. Compared with 100%SLS-PUF material, the rate of thermal degradation of 100%SLS-PUF/20%IFR/2%MMT material decreased by 0.6%/min, and its maximum heat release rate and total heat release were 145.6 kW/m2 and 13.9 MJ/m2, respectively. Moreover, the carbon residue content increased by 13.1 percentage points. At the same time, its apparent density and compressive strength were significantly increased to 58.72 kg/m3 and 296.6 kPa and its thermal conductivity also reached 0.041 W/(m·K).

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Analysis of Aerobic Biological Inhibition Characteristics and Degradation Law of Eucalyptus Chemical Mechanical Pulp Wastewater
Laibao DING, Qingwen TIAN, Ran YANG, Jinwei ZHU, Qi GUO, Guigan FANG
2024, 44 (1):  33-40.  doi: 10.3969/j.issn.0253-2417.2024.01.005
Abstract ( 58 )   HTML ( 1 )   PDF (583KB) ( 80 )  

In this paper, the composition and content of organic matter in the effluent of anaerobic treatment and aerobic treatment of eucalyptus chemical mechanical pulp wastewater were analyzed by GC-MS method. The analysis of number of carbon atoms in the wastewater before and after aerobic treatment was counted, and the main bio-refractory components and degradation rules in the wastewater were analyzed. The results showed that the main residual organic pollutants after anaerobic and aerobic treatment were linalool (C10, 21.21%), methyl p-tert-butyl phenylacetate (C13, 21.39%), dihydromyrcenol (C10, 8.90%), lilial (C14, 6.16%) and citronellol (C10, 4.76%), etc, mainly containing benzene ring organic matter and bacteriostatic components, with biological refractory degradation and bacteriostatic properties. The macroscopic performance was that the removal rate of biological treatment was low. Before and after aerobic treatment, the mass fraction of alcohols in wastewater increased from 19.32% to 51.71%, the mass fraction of aldehydes increased from 3.68% to 13.35%, the mass fraction of esters decreased from 29.75% to 28.32%, and the mass fraction of benzene-containing organics increased from 32.70% to 61.06%, indicating that other organics were degraded more greatly than benzene-containing organics. It was recommended to improve the biological treatment effect by detoxification pretreatment and bioaugmentation to improve microbial activity, reduce the difficulty of subsequent deep treatment, reduce the cost of comprehensive treatment, and achieve low-cost discharge.

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Synthesis and Antifungal Activity of L-Carvone-derived Oxime Sulfonate Compounds
Yupei MENG, Wengui DUAN, Guishan LIN, Wenjing ZHANG, Kaiyue WU
2024, 44 (1):  41-50.  doi: 10.3969/j.issn.0253-2417.2024.01.006
Abstract ( 64 )   HTML ( 4 )   PDF (914KB) ( 86 )  

23 novel L-carvone-derived oxime sulfonate compounds 3a-3w were synthesized through hydroxylamine hydrochloride oximation and o-sulfonylation reactions using L-carvone(1) as the starting material. The structures of the target compounds were characterized by 1H NMR, 13C NMR, FT-IR and HRMS. The antifungal activities of the target compounds against 8 tested plant pathogens were evaluated by agar dilution method. The results showed that the target compounds exhibited certain antifungal activities against the tested plant pathogens at the mass concentration of 50 mg/L. Among them, compounds 3b(R=o-FPh), 3c(R=m-FPh) and 3h(R=p-ClPh) had inhibition rates against Physalospora piricola of 76.7%, 75.9%, and 78.3%(all in B-class activity level), which were better than that of the positive control chlorothalonil. Compound 3h displayed certain broad-spectrum antifungal activity owing to its good inhibition rates of 78.4%, 78.3%, 82.2%, and 78.8%, against Fusarium oxysporum f. sp. cucumerinum, Physalospora piricola, Bipolaris maydis, and Colleterichum orbicalare, respectively(all in B-class activity level). Compound 3b also displayed certain broad-spectrum antifungal activity owing to its good inhibition rates of 76.7%, 77.5%, and 78.6%, against P. piricola, B. maydis, and C. orbicalare, respectively(all in B-class activity level).

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Preparation and Application of Soybean Protein-Polyacrylamide/Composite Salt Anti-freezing Gel Electrolytes
Fusheng YANG, Yuxi LI, Dingkun WANG, Xun ZHAN, Jingya NAN, Chunpeng WANG
2024, 44 (1):  51-57.  doi: 10.3969/j.issn.0253-2417.2024.01.007
Abstract ( 56 )   HTML ( 0 )   PDF (2650KB) ( 73 )  

A soy protein-polyacrylamide composite salt(SPI-PAAm/ZnCl2-LiCl) anti-freezing gel electrolyte with antifreeze performance was prepared using soybean protein(SPI), acrylamide(AAm), ZnCl2 and LiCl as raw materials, and it was applied to hybrid capacitors for the investigation of the electrochemical performance of hybrid capacitor at low temperature. The results of research showed that the addition of ZnCl2 and LiCl broke the hydrogen bonds among the water molecules in the gel electrolyte, and endowed the gel electrolyte with excellent low temperature ionic conductivity and good low temperature mechanical properties. When the molar ratio of ZnCl2 to LiCl was 5∶[KG-*9]12, the performance of antifreeze gel electrolyte was the best. At -70 ℃, the anti-freezing gel electrolyte could maintain structural integrity after 100 tensile cycles under 100% strain, the stress retention rate was more than 65%, the plastic deformation rate was less than 25% and the energy loss coefficient was less than 0.35. The hybrid capacitor based on this anti-freezing gel electrolyte exhibited good electrochemical performance at low temperature, and could work normally at -80 ℃. At low temperature, the energy density was concentrated in the range of 50-200 Wh/kg, and the power density was concentrated in the range of 1 000-30 000 W/kg. Even at -70 ℃, the power density of the hybrid capacitor was nearly 1 000 W/kg and the energy density was more than 10 Wh/kg. Meanwhile, the capacitance retention rate of the hybrid capacitor was more than 94% after 5 000 cyclic charge and discharge at -70 ℃, indicating the excellent cycling performance.

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Analysis of Melting Characteristics of Poplar Ash and Its Influencing Factors
Yang QI, Xiwen YAO, Kaili XU
2024, 44 (1):  58-64.  doi: 10.3969/j.issn.0253-2417.2024.01.008
Abstract ( 55 )   HTML ( 1 )   PDF (10456KB) ( 69 )  

The effect of ashing temperature on the apparent morphology of poplar ash was investigated by muffle furnace burning experiment. The physicochemical properties of poplar ash prepared at different ashing temperatures(600, 800, 1 000 ℃) were compared and analyzed by X-ray diffraction, scanning electron microscopy and energy spectrum analysis. The melting characteristic temperature of poplar ash was measured by ash melting point tester. The relationship between melting characteristic temperature of poplar ash and ashing temperature and residence time was revealed. The poplar ash with ashing temperature of 800 ℃ and residence time of 2 h was treated to the deformation temperature(DT) state. The physicochemical properties of poplar ash during the melting process were analyzed, and the melting performance of poplar ash was further studied. The results showed that the main mineral crystal phases of poplar ash were K2SO4, KCl, SiO2, K2Ca2(SO4)3, Na2Si2O5 and so on when the ashing temperature was 600 ℃ and the residence time was 2 h. Under the conditions of the ash formation temperature of 800 ℃ and the residence time of 2 h, the main mineral crystal phases of poplar ash were MgSiO3, Na2Si2O5, Na6Mg(SO4)4, SiO2, CaSO3 and so on. The XRD pattern of poplar ash at 1 000 ℃ was similar to that at 800 ℃. At 600 ℃, the poplar ash had obvious holes and the surface structure was relatively complete. With the increase of temperature, the surface structure of poplar ash had obvious damage, and the holes in the surface structure gradually increased. The melting characteristic temperature of poplar ash had a positive correlation with the ashing temperature, while there was no obvious linear relationship with the residence time. The deformation temperature(DT), softening temperature(ST), hemisphere temperature(HT) and flow temperature(FT) of poplar ash obtained at 800 ℃ for 2 h were 1 224, 1 254, 1 267 and 1 294 ℃, respectively. When the poplar ash was treated to DT state, the floccule disappeared, and there were still a few holes on the surface, with small particles of ash embedded in the holes.

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Research on the Performance of Furfural Residue Enforced Crude Glycerol-based Polyurethane Foam
Kai FU, Zhenli YAN, Mengyu LI, Wei CHEN, Linda ZHANG, Chun CHANG
2024, 44 (1):  65-73.  doi: 10.3969/j.issn.0253-2417.2024.01.009
Abstract ( 54 )   HTML ( 2 )   PDF (5431KB) ( 74 )  

The biobased polyol(CG-polyol) was synthesized via one-pot method from crude glycerol(GC), a byproduct of biodiesel production, and the furfural residues(FR) was used as the reinforcing filler, which were blended for the preparation of a type of furfural residues-reinforced biobased polyurethane(PU/FR) foam composite material. The effects of FR size(0.25 mm, 0.09 mm samples FR60 and FR180) and addition amount on the PU/FR foam properties were investigated by characterizing the structure and morphology, thermal stability, foaming time, density and compressive strength of PU/FR foam. The results demonstrated that the CG-polyol synthesized by thermal conversion method had an acid number of 1.9 mg/g, a hydroxyl number of 406 mg/g, and a viscosity of 1 092 mPa·s, enabling it for preparing PU foam. The addition of FR prolonged the foaming time, and the maximum rise time and non-stick time increased from 29 and 31 s to 37 and 39 s, respectively. The cell structure of the foam became more complete, the size of the cell was reduced, and the breakage phenomenon was significantly reduced. When the amount of FR added was ≤5%, the density and compressive strength of the foam could be effectively improved. When the addition amount was the same, FR180 showed the most significant improvement in foam properties. Incorporating 5% FR180 into the preparation of PU/FR180-5 foam composite material resulted in a maximum compressive strength of 0.153 3 MPa, representing a 28.1% increase compared to the foam without FR. At this point, the density was 0.051 0 g/cm3 and the thermal conductivity was 0.032 8 W/(m·K). The overall performance of the composite material was better. Moreover, the addition of FR could moderately enhance the thermal stability of the PU foam material. Compared to the foam without FR, the maximum pyrolysis rate temperature(Tmax) of the PU/FR180-5 foam increased from 453 ℃ to 463 ℃.

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Dimensional Stability and Its Mechanism of Plantation Masson Pine Improved by Sol-gel Method
Xiaoling LIU, Songwu CHEN, Linhan HE, Haiying HUANG, Liuliu WANG, Yufen LUO
2024, 44 (1):  74-80.  doi: 10.3969/j.issn.0253-2417.2024.01.010
Abstract ( 54 )   HTML ( 1 )   PDF (4428KB) ( 70 )  

Masson pine is one of the important crucial artificial forest resources in Guangxi region. But the utilization of it was significantly limited in wood industry due to its poor dimensional stability. Herein, a silica-based sol-gel method was employed to improve masson pine. The effect of impregnation time on the dimensional stability of masson pine was discussed. The improvement mechanism of the sol-gel method on masson pine was elucidated through scanning electron microscopy(SEM), energy-dispersive X-ray spectroscopy(EDS), Fourier-transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), and X-ray diffraction(XRD). The results demonstrated that the size stability of the modified masson pine after 6 hours of sol-gel impregnation treatment was the best. Compared with untreated masson pine, the modified wood showed a 5% impregnation rate. The 60 h water absorption mass increase rate reduced from 34.7% to 28.2%. The 60 h hygroscopic volume expansion rate decreased from 16.5% to 11.1%. And the 72 h anti-aging performance decreased from 18.02 color difference value to 11.9. Therefore, the improvement mechanism of the sol-gel method on the dimensional stability of masson pine reflected in two main aspects. Firstly, the entry of moisture could be blocked by the formed glassy layer and expansion structure. Secondly, it bound to the cell walls in the form of hydrogen and chemical bonds to exert permanent swelling effect.

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Preparation Process Optimization and Flame Retardant Performance of Laccase Pretreated Flame-retardant Fiberboard
Haitong SUN, Guoqing NIU, Lun GAO
2024, 44 (1):  81-88.  doi: 10.3969/j.issn.0253-2417.2024.01.011
Abstract ( 49 )   HTML ( 2 )   PDF (4596KB) ( 72 )  

In order to improve the flame-retardant effect of flame retardants in fiberboard, laccase was used to pretreat poplar fiber and then BL-environmental friendly flame retardant was impregnated with poplar fiber to prepare laccase treated flame-retardant fiberboard. Taking the flame retardants loading, oxygen index and smoke density of fiberboard as indexes, the orthogonal experimental design was used to determine the optimal impregnation process. The impregnation effect of poplar fibers was analyzed by oxygen index, smoke density, thermogravimetric(TG) analysis and Fourier transform infrared spectroscopy(FT-IR). The results showed that the prepared fiberboard had the best flame-retardant effect under the conditions of laccase treatment temperature of 50 ℃, enzyme treatment time of 60 min, enzyme dosage of 35 U/g, pH value of 4.8, flame retardant dosage of 50%, flame retardant impregnation time of 80 min and flame retardant temperature of 35 ℃. Under these conditions, the flame retardant loading was 20.3%, the oxygen index was 41.5%, the smoke density was 10.9%, the density was 0.774 g/cm3, the static flexural strength was 30.3 MPa, the elastic modulus was 3 507 MPa, the internal bonding strength was 0.61 MPa, and the thickness expansion rate of water absorbing was 17.4%. Compared with ordinary fiberboard, BL-environmental flame retardant treatment of fiberboard could improve its oxygen index and flame retardant content. Compared with the ordinary fiberboard and the flame-retardant fiberboard prepared by BL-environmentally friendly flame retardant treatment only, the temperature required for laccase-treated flame retardant fiberboard to produce the same weight loss was higher, and the combustion reaction was not easy to be occured in the drying and carbonization stages. The oxygen-containing functional groups and hydroxyl groups of laccase-treated flame-retardant fiberboard decreased significantly, and the flame retardancy of the fiberboard was improved.

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Rapid Determination of Main Component Content of Chinese Gallnut Based on Near Infrared Spectroscopy
Baoshan TANG, Yiwen LIU, Rui HE, Yong ZOU, Shanyu XIE, Hong ZHANG
2024, 44 (1):  89-96.  doi: 10.3969/j.issn.0253-2417.2024.01.012
Abstract ( 49 )   HTML ( 0 )   PDF (2133KB) ( 76 )  

The content of moisture, tannic acid and gallic acid was an important index to evaluate the quality of Chinese gallnut. Generally, it was determined according to the forestry industry standard of the People's Republic of China, which was cumbersome and its timeliness was not guaranteed. In order to study the feasibility of rapid detection of these indicators, 130 Chinese gallnut samples were collected, and chemical values were determined by chemical method. NIR spectroscopy was used to scan Chinese gallnut samples, which was fitted with chemical values measured by traditional methods. The partial least squares(PLS) was used to build a mathematical model, and the correlation coefficient and error of the model were compared to evaluate the prediction performance of the model. The optimal pretreatment methods for moisture, tannic acid and gallic acid in gallnut were FD+MSC, FD and FD+ML, respectively. The characteristic bands of moisture were 9 403.7-7 498.2, 6 012.0-5 774.1, 4 601.5-4 246.7 cm-1, the characteristic bands of tannic acid were 9 403.7-7 498.2, 6 102.0-4 597.7 cm-1, and the characteristic bands of gallic acid were 6 102.0-5 446.3, 4 601.5-4 246.7 cm-1, respectively. The number of principal factors were 9, 10 and 5, respectively. The correlation coefficients of corrected sets(Rc2) for moisture, tannic acid and gallic acid were 0.968, 0.915 and 0.926, the root mean square error of cross validation(RMSECV) were 0.72%, 2.55% and 1.47%, and the relative percent deviation(RPD) were 5.57%, 3.42% and 3.69%, respectively. The correlation coefficients of validation sets(Rp2) were 0.951, 0.891 and 0.891, and root mean square error of prediction(RMSEP) were 0.563%, 1.28% and 0.414%, respectively. The results showed that it was feasible and effective to detect the content of moisture, tannic acid and gallic acid in Chinese gallnut by NIR combined with chemometrics.

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High Density Fermentation of Recombinant Xylanase and Its Directional Preparation of Xylooligosaccharides
Jian ZHAO, Jingcong XIE, Yue JIANG, Jing YANG, Hao XU, Ning ZHANG
2024, 44 (1):  97-104.  doi: 10.3969/j.issn.0253-2417.2024.01.013
Abstract ( 57 )   HTML ( 3 )   PDF (538KB) ( 74 )  

In order to improve the enzymatic hydrolysis efficiency of poplar xylan to xylo-oligosaccharides and reduce the cost of enzymatic preparation of xylo-oligosaccharides, this study focused on the induced expression conditions of Bacteroides-derived xylanase PdoXyn10A produced by high-density fermentation of recombinant Escherichia coli (PET-PdoXyn10A-DE3) and the process conditions of enzymatic hydrolysis to prepare xylo-oligosaccharides. The effects of the inducer concentration, the induced optical density (OD600) value, induction temperature and induction pH value on the production of recombinant xylanase PdoXyn10A by PET-PdoXyn10A-DE3 were studied under 5 L fermenter level. The effects of reaction temperature and pH value on the enzyme activity of corncob xylanase during hydrolysis and the effects of enzyme addition and hydrolysis time on the preparation of xylo-oligosaccharide from poplar acetic acid hydrolysate were determined. The results showed that the activity of recombinase reached 362.67 U/mL and the biomass of recombinant Escherichia coli reached 28.83 g/L under high density fermentation at the optimal induction conditions with 0.25 mmol/L of inducer concentration, induction OD600 value of 55, induction temperature 34 ℃ and induction pH value 7.0. The optimum conditions for the preparation of xylooligosaccharides by enzymatic hydrolysis were as follows: enzyme reaction temperature of 40 ℃, pH value of 5.2, the enzyme dosage of 12 U/mL, and reaction time of 6 h. Under these conditions, the content of xylo-oligosaccharides was 3.21 g/L, the content of xylobiose, xylotriose, xylotetraose, xylopentaose, xylohexaose were 1.09, 0.97, 0.84, 0.18, 0.13 g/L, respectively, and the content of xylose was 1.82 g/L.

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Synthesis and Antifungal Activity of Endo-isocamphanyl-formaldehyole Thiosemicarbazides
Qingying DING, Jiayu CHANG, Zhuanquan XIAO, Jia HU, Zongde WANG, Shangxing CHEN
2024, 44 (1):  105-110.  doi: 10.3969/j.issn.0253-2417.2024.01.014
Abstract ( 61 )   HTML ( 3 )   PDF (452KB) ( 78 )  

5 endo-isocamphanyl-formaldehyole thiosemicarbazide compounds(3a-3e) were synthesized by condensation reactions of camphene derivatives endo-isocamphanyl-formaldehyole with thiosemicarbazide derivatives. Their structures were characterized by IR, MS, 1H NMR and 13C NMR. The mycelial growth rate method was used to study the inhibition effects of the related compounds on the growth of 8 plant pathogenic fungi including Rhizoctonia solani. The results showed that, among 5 compounds, the inhibition rate of endo-isocamphanyl-formaldehyole thiosemicarbazide(3a) was the highest against 8 plant pathogenic fungi. At the mass concentration of 50 mg/L, the inhibition rates of 3a against Colletotrichum gloeosporioides and Colletotrichum acutatum were 91.9% and 97.2%, respectively. The inhibition rates of 3a against Colletotrichum fructicola and Coriolus versicolor were both 100%. The inhibition rates of 3a against Rhizoctonia solani, Sphaeropsis sapinea and Fusariumoxyporum f. sp. niveum were 80.7%, 79.8% and 79.5%, respectively, which were better than that of the positive control sample of Chlorothalonil.

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Effects of Phenolic Compounds and Fatty Acids of Virgin Olive Oil from Wudu on Oil Oxidation Stability
Fengxia TANG, Chuan LI, Hao ZHOU, Hongxia CHEN, Changwei ZHANG, Chengzhang WANG
2024, 44 (1):  111-119.  doi: 10.3969/j.issn.0253-2417.2024.01.015
Abstract ( 50 )   HTML ( 2 )   PDF (2242KB) ( 74 )  

Fatty acids, phenolic compounds, and oxidative stability of virgin olive oils(VOO) from 14 varieties of Ulliri Bardhe(U), Empeltre(E), Koroneiki(K), Ascolana Tenera(As), Zhongshan24(Z), Yuntai14(Y), Picual(P), Arbequina(Arbe), Manzanilla(M), Ezhi8(Ez), Arbosana(Arbo), Coratina(C), Leccino(L) and Frantoio(F) were detected and analyzed. One-way analysis of variance results showed that significant differences were observed between varieties for polyphenol and fatty acid content and oil oxidation stability(p < 0.05). The fatty acids composition of all the analyzed samples conformed to the European Union standard for extra virgin olive oils. The oleic acid content in virgin olive oil was between (56.12±0.24)% (Arbe) and(71.45±0.42)% (C), the linoleic acid content was between (5.73±0.06)% (P) and (15.80±0.05)% (As), and the palmitic acid content was between (12.67±0.12)% (C) and (18.76±0.04)% (Arbe). Secoiridoids were the main phenolic components. The highest total phenolic content was Koroheiki, which was (471.35±29.34) mg/kg, and the lowest content was Arbequina, only (165.65±8.08) mg/kg. Principal component analysis showed that the oxidative stability of varieties rich in oleuropein aglycone, ligstroside aglycone, olive secoiridoid, apigenin and oleic acid was higher, while that of varieties rich in palmitic acid, linoleic acid, oleocanthal, tyrosol and hydroxytyrosol was lower. A multiple linear stepwise regression model based on apigenin, olive secoiridoid, luteolin, and linoleic acid could predict 90.70% of the oil oxidation capacity (p < 0.001).

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Component Analysis and Antifungal Activity of Extract from Senna occidentalis
Jin YANG, Yining ZHANG, Yuhong ZHANG
2024, 44 (1):  120-128.  doi: 10.3969/j.issn.0253-2417.2024.01.016
Abstract ( 58 )   HTML ( 3 )   PDF (1129KB) ( 85 )  

Using stems of Senna occidentalis as raw material, four kinds of extracts were obtained through ultrasonic ethanol extraction and subsequent extracted with different polar solvents. The antibacterial activities of these four extracts against Staphylococcus aureus, Candida albicans, and Acinetobacter baumannii were tested using the filter paper diffusion method. It was found that the chloroform extract exhibited the best overall antibacterial effect. Further separation and purification of the chloroform extract was achieved through chromatography to obtain component 1, component 2, and component 3. Mass spectrometry analysis was used to identify the main antibacterial compounds in component 1 with significant antibacterial activity. The results indicated that component 1, which had relatively low polarity, showed significant antibacterial effects. In component 1, 22 compounds were detected, including 7 flavonoids, 13 anthraquinones, 1 polyphenol, and 1 coumarin. Three individual anthraquinone compounds, namely emodin, chrysophanol, and physcion, were selected for determination of the minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC). The results showed that the MIC and MBC values of these three compounds against A. baumannii and S. aureus were lower than those of the chloroform extract. Among them, emodin, chrysophanol, and physcion exhibited the strongest inhibition activity against S. aureus, with MIC values of 0.2 g/L and MBC values of 0.39 g/L. Physcion showed the best overall inhibitory effect and might be one of the main compounds responsible for the antibacterial activity in S. occidentalis.

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Research Progress on Polymerization and Curing Technology of Urushiol and Its Application in Functional Polymers
Dongxu LI, Juanni ZHANG, Tingting ZHANG, Yan LI, Xingying XUE, Zhiwen QI
2024, 44 (1):  129-137.  doi: 10.3969/j.issn.0253-2417.2024.01.017
Abstract ( 53 )   HTML ( 0 )   PDF (4644KB) ( 77 )  

Urushiol was the common plant polyphenol in China. It was isolated and purified from the lacquer by lacquer tree secretion. The structure contained active groups such as benzene ring, ortho/meta bisphenol hydroxyl group and long(unsaturated) alkane side chain(C15-C20). In recent years, the application of urushiol in membrane functional material technology had made rapid progress. In particular, the preparation of urushiol functional polymers by chemical polymerization and curing technology had been widely used in membrane surface/interface engineering, adhesives, hemostatic agents, and other fields. It was one of the important ways to realize the resource utilization and quality improvement of raw lacquer. This article reviewed the recent domestic and foreign research on the polymerization and curing mechanism of urushiol, as well as heating curing, ultraviolet curing, laccase biomimetic catalysis, metal coordination chelation, organic blend cross-linking, sol-gel reaction, electrospinning and other urushiol curing polymerization technologies. The research progress and main problems of urushiol functional polymers in the application of functional materials such as anti-corrosion coatings, hydrophobic coatings, hemostatic and antibacterial coatings were summarized, which provided theoretical basis and development direction for the commercial application of urushiol functional materials.

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Research Progress on the Safety of Activated Carbon in Gas Phase Adsorption Process
Bin LIU, Songlin ZUO, Jinlong LIU
2024, 44 (1):  138-148.  doi: 10.3969/j.issn.0253-2417.2024.01.018
Abstract ( 54 )   HTML ( 0 )   PDF (614KB) ( 75 )  

Volatile organic compounds(VOCs) were the major reason for air pollution in China, mainly from industrial emissions, containing hydrocarbon, aldehydes, alcohols, ethers and ketones, etc. The granular activated carbon is often applied in the fixed bed. When the activated carbon adsorbs the VOCs, the adsorption heat is released. VOCs adsorption by activated carbon had became the main environmental protection technology at present. However, in the process of VOCs adsorption by activated carbon, the generation of adsorption heat could easily lead to the increase of activated carbon bed temperature, resulting in the fire of activated carbon bed that was a major safety hazard. Therefore, this paper reviewed and analyzed the main factors affecting the ignition point of activated carbon, such as the raw materials, preparation methods and post-treatment processes of activated carbon, from the aspects of the structure and properties of activated carbon, adsorption operation methods and conditions, and VOCs components. The effects of adsorption process such as air humidity, oxygen content, gas flow rate, activated carbon bed depth, and adsorption conditions on the temperature rise of activated carbon bed provided a reference for systematically mastering and evaluating the application safety of activated carbon in gas phase adsorption process. Finally, the main technical problems in this field were pointed out.

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