Table of Content

25 February 2019, Volume 39 Issue 1 Previous Issue    Next Issue

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Research Progress in Screening and Bioactivity of Terpenoid Botanical Pesticides Shichao XU,Huanhuan DONG,Xiaojing ZENG,Zhendong ZHAO 2019, 39 (1):  1-12.  doi: 10.3969/j.issn.0253-2417.2019.01.001 Abstract ( 896 )   HTML ( 19160 )   PDF (1388KB) ( 1042 )   Save This paper reviewed the research progress of screening and activity evaluation of terpenoid botanical pesticides in recent 20 years at home and abroad including the perspective of the antifeedant, repellent, poisonous activities and growth regulation of terpene type insecticides, the inhibition of terpene type antibacterial agents, phytopathogens and the activity of terpene type herbicides in the inhibition of seed germination and seedling growth. The investigation and application of agriculture active terpenoid botanical compounds were systematically introduced and summarized. Based on the existing problems in relevant research fields, the development prospects for the screening and application of terpenoid botanical pesticides was forecasted. This review will provide guidance for the synthesis and application of high-active terpenoid botanical pesticides and devote deeply to the exploitation and utilization of terpenoid resources. Figures and Tables | References | Related Articles | Metrics

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Progress on Preparation and Application of 5-Hydroxymethylfurfural Si LU,Qiong WANG,Xun LI,Wei QI,Zhongming WANG,Zhenhong YUAN 2019, 39 (1):  13-22.  doi: 10.3969/j.issn.0253-2417.2019.01.002 Abstract ( 2525 )   HTML ( 3049424 )   PDF (786KB) ( 1545 )   Save 5-Hydroxymethylfurfural (HMF) is one of the most important biomass-based platform molecules and widely used in the preparation of multifunctional compounds such as fine chemicals, key pharmaceutical intermediates, functional polyesters, solvents and liquid fuels. At present, the preparation of HMF is a hot spot in the field of biomass research, and the raw materials and methods for preparing HMF have been continuously expanded. This paper reviews the main preparation methods and research progress of HMF. Catalysis systems for HMF preparation is systematically described, including the types of the catalysts (mineral acids, ionic liquids, metal chlorides, solid acids and others) used in the catalytic process and the solvent systems. Then, the preparation paths and applications of important derivatives from HMF are summarized. Finally, suggestions for future research on HMF are provided based on the understanding of problems existing in the current research. Figures and Tables | References | Related Articles | Metrics

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Preparation and Characterization of Self-catalyzing Polyol Dispersions from Terpinene-maleic Ester Based Epoxy Resin Guomin WU,Jian CHEN,Shuping HUO,Guifeng LIU,Can JIN,Zhenwu KONG 2019, 39 (1):  23-28.  doi: 10.3969/j.issn.0253-2417.2019.01.003 Abstract ( 640 )   HTML ( 4 )   PDF (1755KB) ( 531 )   Save Self-catalyzing polyol dispersions with tertiary amine groups (TBP or TDP) were prepared by reaction of terpinene-maleic ester based epoxy resin (TME) with N-benzylethanolamine (BEA) or diethanolamine (DEA). The tertiary amine groups in the polyol structure could catalyze the crosslinking reaction between hydroxyl group and isocyanate group in the crosslinking reaction of polyol dispersions and polyisocyanate to form two-component waterborne polyurethane. Suitable synthesis conditions were obtained by studying the effect factors of synthesis reaction. The optimum reaction conditions of the preparation of TME based polyols TBP or TDP were reaction at 80 ℃ for 1 h with using ethanol as solvent and the amount of ethanol was about 10% of the total quality of reactants. The chemical structures of the polyols were characterized by FT-IR and NMR and the average molecular weight of the polyoys was determined by GPC. The effect of neutralization degree on the particle size distribution of polyol dispersions was investigated by laser particle sizer. When the neutralization degree was 90%, the particle size distribution of polyol dispersions was multimodal and the stability of the dispersions was poor. However, when the neutralization degree was 100%, the particle size distribution of the dispersions was unimodal and achieved nanoscale dispersion. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Properties of Oxidative Modified Satium Lignosulfonate/Graphene Quantum Dots Composites Lina XU,Xiaohua YANG,Haiyang DING,Mei LI,Jianling XIA 2019, 39 (1):  29-34.  doi: 10.3969/j.issn.0253-2417.2019.01.004 Abstract ( 692 )   HTML ( 20 )   PDF (1453KB) ( 637 )   Save Oxidative modified sodium lignosulfonate/graphene quantum dots (HSL/GQDs) composites was synthesized using by products of the sulfite-pulping procedure (sodium lignosulfonate) and citric acid.Fluorescence spectroscopy, UV-vis spectra, and TEM were used to investigate the optical properties, structure and ions detection of the prepared HSL/GQDs.The HSL/GQDs exhibited strong fluorescence, which present two times high intensity(F0)than that of the free GQDs. The experimental results showed that HSL/GQDs could detect Fe3+ with high sensitivity and specificity according to the change of the fluorescence intensity. The Fe3+ concentration and the fluorescent quenching intensity of prepared HSL/GQD safter adding Fe3+ presented a good linearity in range of 10 -500 μmol/L, with alinear equation of F/F0=0.85112-0.00111C(Fe3+)(R2=0.99). Figures and Tables | References | Related Articles | Metrics

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Synthesis and Antibacterial Activity of Hydronopol Dimethyl Alkyl Ammonium Halide Xuezhen FENG,Zhuanquan XIAO,Pingying LU,Guorong FAN,Zongde WANG 2019, 39 (1):  35-40.  doi: 10.3969/j.issn.0253-2417.2019.01.005 Abstract ( 594 )   HTML ( 6 )   PDF (538KB) ( 626 )   Save Nine hydronopol quaternary ammonium salts(hydronopol dimethyl alkyl ammonium halide), which were hydronopol dimethyl ethyl ammonium bromide(2a), hydronopol dimethyl n-propyl ammonium bromide(2b), hydronopol dimethyl n-butyl ammonium bromide(2c), hydronopol dimethyl n-pentyl ammonium bromide(2d), hydronopol dimethyl benzyl ammonium bromide(2e), hydronopol dimethyl benzyl ammonium chloride(2f), hydronopol dimethyl ethyl ammonium iodide(2g), hydronopol dimethyl n-propyl ammonium iodide(2h), and hydronopol dimethyl n-butyl ammonium iodide(2i), were synthesized by the reaction of hydronopol dimethyl amine and 9 halogenated hydrocarbons, respectively. The identification and structural analysis were carried out by using FT-IR, MS and NMR methods, and the inhibition effects of the nine compounds on eight plant pathogens were tested by the method of mycelium growth rate method. The results showed that under the concentration of 500 mg/L, 9 compounds had certain inhibitory effects on the 8 plant pathogenic fungi, among which the bacteriostatic performance of 2d were the best, the bacteriostatic rates against Fusarium proliferatum, Alternaria kikuchiana, Sclerotinia sclerotiorum, Ceratosphaeria phyllostachydis, and Sphaeropsis sapinea reached 100%, and 2b, 2c and 2f also had excellent results, the bacteriostatic rate reached 100%. Figures and Tables | References | Related Articles | Metrics

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Separation, Purification and Hydrophilic Derivative Synthesis of Ginkgo biloba Leaves Polyprenol Changwei ZHANG,Yulu MA,Ran TAO,Jianzhong YE,Chengzhang WANG 2019, 39 (1):  41-45.  doi: 10.3969/j.issn.0253-2417.2019.01.006 Abstract ( 501 )   HTML ( 103 )   PDF (799KB) ( 788 )   Save The analytical methodology and method performance for the determination of polyprenol in Ginkgo biloba leaves were investigated for the first time. The results showed that of the high performance liquid chromatography with C18 as chromatographic column, isopropanol methanol(volume ratio, 32:18) as mobile phase, 210 nm as detection wavelength showed high precision(RSD=0.89%) and good stability(RSD=3.26%). In addition, the average standard recovery and RSD value of polyprenol were 97.4% and 1.75%, respectively. Then, polyprenol with the purity of 98.6% was obtained by extraction with n-hexane, saponification, de-waxing with ethanol and acetone, and silica gel column chromatography(V(diethyl ether):V(n-hexane)=3:97). On this basis, the terminal hydroxyl group of high-purity polyprenol was modified to synthesize aminopolyprenol. Firstly, by mitsunobu reaction with phthalimide, followed by reduction reaction with hydrazine hydrate, to obtain aminopolyprenol. The structure of amino polyprenol was characterized by infrared and nuclear magnetic resonance spectroscopy, which confirmed the aminopolyprenol was successfully synthesized. Figures and Tables | References | Related Articles | Metrics

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Isocyanate Modified Bamboo Surface and Its Corrosion Resistance Property He GAO,Yong SUN,Xing TANG,Xianhai ZENG,Lu LIN 2019, 39 (1):  46-52.  doi: 10.3969/j.issn.0253-2417.2019.01.007 Abstract ( 518 )   HTML ( 19 )   PDF (2667KB) ( 787 )   Save The process of enhancing the corrosion resistance of natural bamboo by modifying its surface with isocyanate was developed. The bamboo treated with hot water or alkali was modified with dicyclohexylmethane 4, 4′-diisocyanate(HMDI) and achieved the bamboo samples H-HMDI-bam and A-HMDI-bam, respectively. The investigation on corrosion resistance mechanism indicated that the number of hydroxyl groups on the surface of the modified bamboo was significantly reduced after modification, while the numbers of the carbonyl and amide groups increased. HMDI was successfully grafted onto the fiber surface and formed the flocculent encapsulation. The loadings were 6.342 mmol/cm2 for A-HMDI-bam and 4.080 mmol/cm2 for H-HMDI-bam, respectively. The hydrophobicity of the modified sample was significantly enhanced, especially for H-HMDI-bam, whose water absorption decreased from 68.7% (raw material) to 35.5%, and the pore size and pore volume decreased significantly to 33.48 nm and 0.039 0 cm3/g, respectively. The SEM images showed that the sample coated with HMDI was hardly corroded, corresponding to the grade of 0-1, which was similar to that of the sample treated by the traditional carbonization process in industry. Figures and Tables | References | Related Articles | Metrics

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Characterization of Phenolic Foam Modified by Silanized Nano-SiO2 Na ZHANG,Lihong HU,Yajun GUO,Yonghong ZHOU 2019, 39 (1):  53-60.  doi: 10.3969/j.issn.0253-2417.2019.01.008 Abstract ( 582 )   HTML ( 6 )   PDF (1444KB) ( 482 )   Save Nano-SiO2 was prepared by sol-gel method. Then the silanization of nano-SiO2 was carried out by adding silane coupling agent 1, 1, 3, 3-tetramethyldisiloxane and obtained a silanized nano-SiO2 that was used to modify phenolic resins (PR1 -PR6). These modified phenolic resins were then converted into the corresponding phenolic foam (PF1 -PF6). FT-IR, TGA/FT-IR and TGA were applied to investigated the properties of these modified phenolic resins. The test results showed that the modified phenolic resin has successfully incorporated silanized nano-silica via the chemical crosslinking reaction that formed Si—O—Si and Si—O bonds. Free phenol test results showed that with the increase of nano-silica content, the free phenol content drastically decreased. However, the same content of tetraethoxysilane(TEOS) with the different content of silane coupling agent had little effect on the free phenol content. When the silicone grease was 3.22 g and the silane coupling agent was 2 g, PR4 composition had the best performance. It was also found that with the increase of nano-silica content, the hydroxymethyl content rapidly increased to a high value. The mechanical properties test showed that when the mass fraction of silicone grease was 0.5% (calculated by the mass of phenolic resin, the same below)and the silane coupling agent was 0.3%, the flexural strength and compressive strength of PF4 were increased by 73.3% and 83.4% respectively, while compared with those of PF1, which resulted in the improve of the mechanical properties of the foam. In view of these test results, PF4 has exhibited the best modification effect and met the initial requirements. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Spectra Performance of Dehydroabietic Acid-based Triarylamine with Double Naphthalenes Guanni TAN,Yanan GAO,Hong GAO,Shibin SHANG,Zhanqian SONG 2019, 39 (1):  61-66.  doi: 10.3969/j.issn.0253-2417.2019.01.009 Abstract ( 629 )   HTML ( 5 )   PDF (1152KB) ( 619 )   Save A novel dehydroabietic acid-based triarylamine compound with two naphthalene was synthesized via esterification, bromation, nitration, hydrogenation reduction and C—N cross-coupling with the starting material dehydroabietic acid, which was obtained with disproportionated rosin as raw material, its structure was characterized by IR、1H NMR、13C NMR and mass spectrometry. The absorption spectra and fluorescent spectra of the compound in 5 kinds solvents with different polority were studied. The compound had three absorption peaks, the first adsorption peaks of compouds in methanol, dioxane and cyclohexane solvents were at 218 nm, the adsorption peaks showed red shift in tetrahydrofuran and dichloromethane solvents, and the absorbance were different; however, the absorption wavelengths were the same and the absorbance had little difference at 265 and 342 nm. Fluorescent emission wavelengths and intensities of title compound exsited marked difference in different polarity solvents, the emission wavelength was the biggest(448 nm), but the intensity was the smallest in bigger polority methanol; on the contrary, the emission wavelength was the smallest(405 nm) but the intensity was the biggest in smaller polarity cyclohexane solution; however, the emission wavelength increased gradually in dioxane, tetrahydrofuran and dichloromethane solutions with polarity decreasing. The differences in UV absorption spectra and fluorescence emission spectra of compound in different polar solvents indicated that it had significant solvatochromism effect. The fluorescence lifetime and quantum efficiency of compound in methanol were 3.72 ns and 8.32%. Figures and Tables | References | Related Articles | Metrics

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Preparation of Lignin-based Carbon Nanosheet and Its Electrochemical Property Jihui LI,Kang SUN,Yaoguang SONG,Ao WANG,Jianchun JIANG 2019, 39 (1):  67-74.  doi: 10.3969/j.issn.0253-2417.2019.01.010 Abstract ( 768 )   HTML ( 74 )   PDF (2833KB) ( 759 )   Save To obtain two-dimensional carbon materials with low cost and high performance, lignin-bosed carbon nanosheet was prepared using sodium lignosulfonate as carbon sources and boron acid as template followed by solution mixing, high temperature carbonization and refluxing with boiling water. The carbon nanosheets obtained with m(boron acid):m(sodium lignosulfonate)=1:1, 5:1 and 10:1 were marked as SLB-1, SLB-5 and SLB-10. The morphology of sample was characterized by SEM and TEM. XRD, XPS and Raman were used to demonstrate its constituent, structure and property. The electrochemical performance of carbon nanosheet was tested by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) measurements. The results revealed that the sample SLB-5 exhibited well-developed teo-dimensional lamellar structure. The thickness of the carbon nanosheed could be regulated by the mass ratio of boron acid and sodium lignosulfonate. SLB-5 presented somewhat graphitic structure, the template was completely removed and the content of oxygen was 16.63%. The capacitance of SLB-5 could reach 350.79 F/g at 1 A/g, which could also maintain almost 79.95% as the current density increased to 10 A/g. After 5 000 cycles, endurance test at 5 A/g, its capacitance could still retain 90%. Figures and Tables | References | Related Articles | Metrics

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Preparation and Characterization of Cellulose-fattyacid-furfural Derived Thermoplastic Elastomer via ATRP Chuanwei LU,Chunpeng WANG,Fuxiang CHU,Jifu WANG 2019, 39 (1):  75-80.  doi: 10.3969/j.issn.0253-2417.2019.01.011 Abstract ( 653 )   HTML ( 6 )   PDF (1562KB) ( 512 )   Save The grafted block copolymers, ethyl cellulose-g-lauryl methacrylate-b-tetrahydrofurfuryl methacrylate(EC-g-P(LMA-b-THFMA)) was successfully prepared via "grafting from" atom transfer radical polymerization(ATRP) through two-step polymerization strategy. Thermal property analysis showed that this copolymer had two thermal transitions(-35 ℃ and 49-56 ℃), indicating of the presence of microphase separation in the copolymer. Mechanical property analysis showed that the copolymer had excellent thermoplastic elastomer behavior with the elongation of 89%-147% and tensile strength of 1.7-9.5 MPa. The cycilic tensile mechanical properties analysis indicated that the elastic recovery of EC-g-P(LMA-b-THFMA200) was more than 92%. Compared with the linear block polymer P(LMA-b-THFMA), it could be found that the introduction of cellulose significantly enhanced the mechanical properties of graft copolymer. The mechanical strength of graft copolymer was increased by 1.36 times while compared with that of P(LMA-b-THFMA). Figures and Tables | References | Related Articles | Metrics

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Pretreatment of Corncob by Dilute Acetic Acid Hui QIAO,Shuiping OUYANG,Lei LIU,Jia OUYANG 2019, 39 (1):  81-87.  doi: 10.3969/j.issn.0253-2417.2019.01.012 Abstract ( 587 )   HTML ( 6 )   PDF (2694KB) ( 654 )   Save A dilute acetic acid pretreatment technology for corncob was established to remove lignin, convert hemicellulose into xylose and improve the enzymatic hydrolysis yield. The effects of acetic acid concentration, pretreatment temperature and time on pretreatment goal were investigated and the results showed that most of the hemicellulose and partial lignin in the corncob were removed by pretreating with 5% acetic acid. Moreover, the pretreated corncob was easy to be hydrolyzed. Under the optimal condition(pretreatment temperature of 160 ℃, holding time of 60 min, acetic acid concentration of 5% and solid-liquid ratio of 1:8(g:mL), the yield of corncob solid residue was 53.75%, the cellulose retention rate of corncob solid residue could reach 93.17%, and 87.36% of the hemicelluloses and 25.04% of the lignin were removed. Meanwhile, 15.56 g/L xylose was obtained from the pretreatment liquid. The maximum enzymatic hydrolysis yield of pretreated corncob solid could be up to 92.69% within 72 h. Figures and Tables | References | Related Articles | Metrics

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Effect of Steam Explosion on Extraction of Bioactive Components and Gutta-percha from Barks of Eucommia ulmoides Oliver Jinjin WEI,Donglin XIN,Xiang CHEN,Xiyu QUAN,Junhua ZHANG 2019, 39 (1):  88-94.  doi: 10.3969/j.issn.0253-2417.2019.01.013 Abstract ( 549 )   HTML ( 4 )   PDF (708KB) ( 614 )   Save Eucommia ulmoides Oliver bark was pretreated by steam explosion, and then the pretreated bark was hydrolyzed by cellulase to extract bioactive components and gutta-percha. Effect of steam explosion pretreatment on the bioactive components, yield and molecular weight of gutta-percha from bark of E. ulmoides Oliver were investigated. The results showed that the optimal conditions for the extraction of bioactive components from untreated barks using ethonal sonication-assisted method were 40% ethanol, ultrasonic power 200 W, extraction temperature 40 ℃ and extraction time 40 min. When the conditions of steam explosion pretreatment were 3.25 MPa and 1 min, the yields of flavonoids and chlorogenic acid using ethonal sonication-assisted method were 26.83 and 1.22 mg/g, respectively, and the yields of flavonoids and chlorogenic acid extracted by cellulase hydrolysis were 19.17 and 0.93 mg/g, respectively. The solid residue of pretreated barks after enzymatic hydrolysis was used to extract gutta-percha. When the conditions of steam explosion pretreatment were 0.52 MPa and 15 min, the yields of gutta-percha was 5.92%, and the Mw and Mn of gutta-percha were 28.39×104 and 6.45×104, respectively. Figures and Tables | References | Related Articles | Metrics

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Effect of Microwave Pretreatment on Properties of Eucalyptus Chemical Mechanical Pulp Lulu WEI,Yongjun DENG,Shanming HAN,Hongbin LI,Long LIANG,Guigan FANG 2019, 39 (1):  95-100.  doi: 10.3969/j.issn.0253-2417.2019.01.014 Abstract ( 518 )   HTML ( 2 )   PDF (1218KB) ( 496 )   Save The effects of microwave on the permeability of eucalyptus were studied by comparing the liquid absorption of wood chips under microwave with that under water bath. Under the same immersion conditions(NaOH 4% and mass fraction of wood chips 20%), the absorbed liquid quality of the microwave treated wood chips was significantly higher than that of the water bath. Microwave treatment for 5 minutes could reach the same absorbed liquid quality of 45 minutes in the water bath treatment, greatly improving the impregnation efficiency of wood chips. Then, microwave was used in the pre-impregnation of chemical mechanical pulping. The whiteness of the second stage bleaching pulp obtained by microwave impregnation could reach up to 68.9%(ISO), which was 3 - 6 percentage points higher than that of samples obtained by steaming impregnation. When the freeness of Canada was 305 mL, the tensile strength index could reach 19 N·m/g, the tear index could reach 2.15 mN·m2/g, and the bursting index could reach 0.8 kPa·m2/g. Furthermore, the tensile strength index was increased by 3 N·m/g on average, and the tear index was increased by about 0.2 mN·m2/g, while the bursting index was increased by about 0.1 kPa·m2/g. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Complexation Properties on Metal Ion of Isolongifolenone Oxime Chenliang WU,Yunyun WANG,Xu XU,Wen GU,Shifa WANG 2019, 39 (1):  101-107.  doi: 10.3969/j.issn.0253-2417.2019.01.015 Abstract ( 507 )   HTML ( 6 )   PDF (1190KB) ( 526 )   Save Isolongifolenone oxime was prepared from isolongifolenone and hydroxylamine hydrochloride by oximation reaction. Effects of the reaction conditions on the yield of isolongifolenone oxime were investigated by single factor method and ortnogonal experiments. The optimum reaction conditions were as follows:sodium acetate as the catalyst, the molar ratio of isolongifolenone, hydroxylamine and sodium acetate 1:1.3:0.55, reaction temperature 76 ℃ and reaction time 6 h. The yield of isolongifolenone oxime reached 99.0% under the optimum reaction conditions.The structure of the isolongifolenone oxime was determined by FT-IR, 1H NMR, GC-MS and single crystal X-ray diffraction. Complexation properties of isolongifolenone oxime on metal ions including Cu2+, Co2+, Cd2+, La3+, Pb2+, Ag+ were examined, and the results showed that isolongifolenone oxime exhibited better complexing effect to Cu2+ than that to other metal ions. It was also known from the FT-IR that the complexation between Cu2+ and isolongifolenone oxime was formed by Cu-N and Cu-O coordination bonds. Figures and Tables | References | Related Articles | Metrics

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Optimization of Vacuum Extraction of Total Saponins from Sapindus mukorossi Gaertn and Its Herbicidal Activity Xiaojiang MA,Jin WANG,Feng TANG,Quan GAO,Wei LIU,Li SONG 2019, 39 (1):  108-114.  doi: 10.3969/j.issn.0253-2417.2019.01.016 Abstract ( 660 )   HTML ( 6 )   PDF (793KB) ( 580 )   Save Vacuum extraction method was selected to improve the extraction efficiency of total saponins from Sapindus mukorossi Gaertn with water as extraction solvent. The contents of total saponins were determined by spectrophotometry and ultra-performance liquid chromatography(UPLC). Based on single factor experiments, orthogonal design was used to optimize the process parameters. The optimized extraction process was extraction temperature 60 ℃, extraction time 1 h and the solid-to-liquid ratio 1:14(g:mL). Under these conditions, the extraction rate of total saponins in S. mukorossi fruits was 15.34% by using spectrophotometry. The herbicidal activity of the extract was evaluated by water agar medium method. The fruit extract exhibited obvious root-growth inhibition activity against Trifolium pratense L. with EC50 value of 0.116 g/L. The herbicidal active compounds were tentative identified as triterpenoid saponins by thin-layer chromatography(TLC). Figures and Tables | References | Related Articles | Metrics

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Effect of Metal Ions on Interaction Between Helicid and Bovine Serum Albumin Dandan ZHAO,Xiaowei JIN,Jingnan SHI,Yuzhen ZHANG,Hedong BIAN,Yongzhi LIAO 2019, 39 (1):  115-122.  doi: 10.3969/j.issn.0253-2417.2019.01.017 Abstract ( 526 )   HTML ( 2 )   PDF (1852KB) ( 399 )   Save The effect of Fe3+, Cu2, Ni2+, Zn2+on the interaction reaction between helicid(HLD)and bovine serum albumin(BSA)was investigated by fluorescence spectroscopy under similarity physiological conditions. The results showed that the fluorescence of BSA was quenched via HLD by forming stable complexes. The quenching constants(kq)calculated by Stern-Volmer equation under 293, 298 and 303 K were 6.316, 5.147 and 4.040×1012 L/(mol·s), respectively. The binding constants(K) were 9.10×105, 7.76×105, and 4.97 ×105 L/mol, respectively. The distance between the tryptophan residues of BSA and HLD was 4.79 nm by using Föster′s equation, and it decreased after interaction with metal ions. The theromodynamic parameters indicated that the force between HLD and BSA were hydrogen band and van der Waals forces. The effects of HLD and different metal ions on the secondary structure of BSA were studied using circular dichroism(CD) spectroscopy. The results showed that the addition of HLD changed the conformation of BSA in the binding reaction, and α-helix content decreased. The secondary structure of BSA was also changed by the addition of metal ions and α-helix content further reduced obviously. Figures and Tables | References | Related Articles | Metrics

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Application of Maleopimaric Acid Epoxy Resin in Paper-based Copper Clad Laminate Yi'ang SUN,Chuanhui ZONG,Fei WANG,Na ZHANG,Aixiang LI 2019, 39 (1):  123-128.  doi: 10.3969/j.issn.0253-2417.2019.01.018 Abstract ( 532 )   HTML ( 3 )   PDF (751KB) ( 564 )   Save The maleopimaric acid epoxy resin(MPAER) was synthesized with maleopimaric acid(MPA) as the raw material, and the paper-based copper clad laminate(CCL) was prepared by replacing E-51 epoxy resin with the MPAER. The resin and its cured product were characterized by FT-IR and tested by TGA. The thermal properties of the cured resin and the effect of the resin on the gelation time of the copper clad laminate were investigated. The effects of the replacement amount of the resin on the soldering resistance, peel strength, bending strength and flammability of the copper clad laminate were discussed. The results showed that the cured product of maleopimaric acid epoxy resin had better thermal properties. When the replacement amount of the resin was less than 60%, the gelation time was shortened, and when it was more than 60%, the gelation time became long. When the replacement amount of the resin was 20%, the comprehensive performance of the prepared copper clad laminate was the best with the peel strength of 1.7 N/mm, the soldering resistance of 55 s, and the warp and weft bending strengths of 362.9 N/mm2 and 317.7 N/mm2, respectively, which were better than those of the copper clad laminates prepared by E-51 epoxy resin. When the replacement amount of the resin was less than 40%, the flammability of copper clad laminate reached the highest flame retardant level of UL94V-0. Figures and Tables | References | Related Articles | Metrics