Table of Content

28 February 2023, Volume 43 Issue 1 Previous Issue    Next Issue

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Technical Development and Policy Suggestions of Feed and Additives from Forest Sources Jianchun JIANG 2023, 43 (1):  1-14.  doi: 10.3969/j.issn.0253-2417.2023.01.001 Abstract ( 244 )   HTML ( 1717 )   PDF (1007KB) ( 356 )   Save China is the largest feed producing and consuming country in the world. The huge production and consumption of feed required a huge amount of raw materials. The problems of supply tightly of feed grain and lack of arable land were highlighted. The total cumulative imports of soybean feed raw materials had reached 96.52 million tons in 2021. Developing forest source feed could partial substitute grain feed, which can effectively solve the contradiction between supply and demand of feed, and promote the high-quality and integrated development among agriculture, forestry and animal husbandry. This paper summarized the preparation and utilization technology of plant protein feed, insect protein feed, functional oligosaccharide feed additive and forest source feed additive of extract in forest feed and additives in China. The bottleneck problems in industrial development were also analyzed, such as low utilization rate of resources, lack of industrial core technology, weak support of science and technology and weak industrial foundation, etc. Finally, in the fields of industrial development planning, scientific and technological innovation system and policy support, policy suggestions were proposed forward to develop Chinese forest sources feed and additives industry. Figures and Tables | References | Related Articles | Metrics

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K/Ca Catalytic Steam Gasification of Sawdust for Production of Hydrogen-rich Syngas Jurong REN, Yunhong SU, Yunjuan SUN, Hao YING, Zhongzhi YANG, Le XU 2023, 43 (1):  15-24.  doi: 10.3969/j.issn.0253-2417.2023.01.002 Abstract ( 230 )   HTML ( 269 )   PDF (2111KB) ( 354 )   Save KOH/dolomite composite catalyst was used to catalyze steam gasification in a fixed-bed gasifier with pine sawdust as raw material. The effects of catalyst preparation conditions, reaction temperature, steam flow rate and catalyst dosage on the evaluation indexes of gasification characteristics such as gasification synthesis hydrogen content, gas yield, hydrogen yield and carbon conversion rate were investigated. SEM, XRD and pore structure analysis of the K/Ca composite catalyst were carried out. The results showed that K element was well loaded on dolomite. The K/Ca composite catalyst prepared by KOH mass fraction of 6%, K/Ca molar ratio of 2∶1 and calcination at 900 ℃ had the best catalytic performance. When the gasification temperature increased from 600 to 750 ℃, the H2 volume fraction increased from 40.70% to 59.09%, and the hydrogen yield rate increased from 16.38 to 90.64 g/kg. However, the catalyst activity decreased owing to the continuous increase of temperature, and the H2 volume fraction and hydrogen yield decreased as well. When the steam flow rate increased from 0.4 to 1.0 mL/min, the H2 volume fraction increased from 52.75% to 59.09%, and the hydrogen yield increased from 68.14 to 90.64 g/kg. Further increase of steam flow would lead to heat loss in the system, which would reduce the H2 volume fraction and hydrogen production rate. When the mass ratio of catalyst to raw material was 0.3 g/g, the volume fraction of H2 was 59.09% and the yield rate of hydrogen was 90.64 g/kg. When the mass ratio increased to 0.6 g/g, the volume fraction of H2 decreased to 58.50%, and the hydrogen production rate increased to 103.18 g/kg. When the mass ratio of biomass continuously increased, above growth became significantly slow, that was, the catalytic reaction basically reached equilibrium. With the consideration of the various aspects, the optimal conditions of K/Ca composite catalyst for pine sawdust steam gasification were as follows: reaction temperature of 750 ℃, water vapor flow rate of 1.0 mL/min, and mass ratio of catalyst to raw material of 0.6 g/g. At this time, volume fraction of H2 in product gas was 58.50%, hydrogen production rate was 103.18 g/kg, the low calorific value was 10.94 MJ/m3, and carbon conversion was 83.25%. Figures and Tables | References | Related Articles | Metrics

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Preparation and Characterization of Ni-B/CxNy@mSiO2 Catalysts and Their Catalytic Properties for Rosin Hydrogenation Yilu SHI, Fengli YU, Bing YUAN, Congxia XIE, Shitao YU 2023, 43 (1):  25-33.  doi: 10.3969/j.issn.0253-2417.2023.01.003 Abstract ( 217 )   HTML ( 166 )   PDF (5399KB) ( 297 )   Save A kind of Janus amphiphilic carbon silicon double skeleton nanomaterial CxNy@mSiO2 consisting of inner cavity, hydrophobic nitrogen doped carbon inner layer and hydrophilic silicon dioxide outer layer was successfully prepared. Ni-B alloy nanoparticles were loaded on amphiphilic carbon-silicon nanomaterials for the first time to prepare Ni-B/CxNy@mSiO2. The catalyst was also used for the aqueous phase hydrogenation of rosin. The structure of the catalyst was analyzed and characterized by SEM, TEM, N2 adsorption-desorption, XRD and XPS. The results of structural analysis showed that the catalyst had a hollow structure of nanomaterials with large specific surface area, which was conducive to mass transfer and substrate enrichment. The doping of N atoms in the inner carbon skeleton made the additional metal nanoparticles attached, and the fine Ni-B amorphous alloy particles were uniformly dispersed in the CxNy@mSiO2 hollow nanospheres and mSiO2 shell layers. The hydrophilic silica shell could improve the stability and dispersion of the catalyst. In the water/oil two-phase reaction system, the amphiphilic nano catalyst as a solid foaming agent greatly promoted the dissolution of H2 and the contact with the substrate. The synergistic effect between Ni and B atoms could significantly improve the catalytic activity. Therefore, the non noble metal Ni-based nano catalyst showed good catalytic activity for rosin hydrogenation, and its catalytic activity was basically equivalent to those of noble metal Ru and Pd catalysts. Under the conditions of 160 ℃, 4.0 MPa, 4 h, water oil volume ratio of 1∶2 and catalyst dosage(based on rosin mass) of 10%, the conversion rate of rosin was 98.77%, the selectivity of tetrahydroabietic acid was 23.89%, and the GC content of dehydroabietic acid was less than 1%, indicating that the product reached the standard of Grade I hydrogenated rosin. The developed amphiphilic Ni-B nano catalyst showed stability and good reusability. When it was reused for 6 times, its catalytic activity did not decrease significantly. Figures and Tables | References | Related Articles | Metrics

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Highly Effective Separation of Paclitaxel by Using Core-shell Rosin-based Polymer Bonded Silica as Liquid Chromatography Stationary Phase Hao LI, Wenbo XIE, Lei ZENG, Liuyu YI, Wen LI, Fuhou LEI 2023, 43 (1):  34-42.  doi: 10.3969/j.issn.0253-2417.2023.01.004 Abstract ( 185 )   HTML ( 120 )   PDF (1865KB) ( 255 )   Save A rosin-based core-shell polymer bonded silica(RP@SiO2) stationary phase was prepared by the radical polymerization of fumaropimaric acid tri(β-acryloxyl ethyl) ester(FATE) onto alkylated silica(TPM-SiO2). The RP@SiO2 stationary phase was characterized and evaluated, the separation performance and mechanism of RP@SiO2 column for paclitaxel(PTX) and its analogs were discussed, and it was used for the separation and purification of PTX from crude yew-bark extract. The results showed that FATE was successfully bonded to the surface of silica, the core-shell structure material was successfully prepared, and the average particle size of RP@SiO2 was about 5 μm. The RP@SiO2 column was a typical reversed-phase column similar to C18 column, showing excellent chromatographic performance, satisfactory performance reproducibility, and typical reversed-phase chromatographic behavior. The RP@SiO2 column was used to separate paclitaxel analogs, and the separation degree of continuous elution samples was more than 6.6. Stoichiometric displacement theory for retention(SDT-R) and van't Hoff thermodynamic analysis showed that hydrophobic interactions determined the analyte retention, and the separation of paclitaxel analogs on RP@SiO2 column was an exothermic process driven by enthalpy. Furthermore, SDT-R could be used to explain its retention mechanism. The RP@SiO2 column was employed to separate and purify paclitaxel from crude yew-bark extract, increasing paclitaxel purity from 6% to 81%. Figures and Tables | References | Related Articles | Metrics

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Synthesis of Carbamates and Their AChE Inhibitory Activity Jing WANG, Yuxiang CHEN, Shengnan LI, Hongmei ZHANG, Jianxin JIANG, Zhendong ZHAO 2023, 43 (1):  43-50.  doi: 10.3969/j.issn.0253-2417.2023.01.005 Abstract ( 225 )   HTML ( 208 )   PDF (625KB) ( 342 )   Save Using 3-carene, a major component of turpentine, as the raw material, 3-isopropyl-5-cresol(1) and carvacrol(2) were first synthesized, and then 14 carbamate compounds containing isopropyl cresol structure were further prepared by their reactions with isocyanates(method A) or carbamoyl chlorides(method B). The acetylcholinesterase(AChE) inhibitory activities for all synthetic compounds were studied. The research results showed that the reaction of phenolic compounds with isocyanates was an efficient synthesis process for the preparation of carbamates. The larger N-substituent structure in the isocyanate, the easier reaction occurs, and the molar yield of aryl substitution products could reach more than 90%. In terms of AChE inhibition, the activities of 3-isopropyl-5-cresol derivatives were generally higher than those of carvacrol derivatives. The activities of N-aliphatic substituted products were significantly higher than those of N-aryl substituted products, and the activities of short-chain aliphatic substituted products were higher than those of long-chain aliphatic and cycloaliphatic groups substituted products. The N-methyl substituted product of 3-isopropyl-5-cresol showed the excellent AChE inhibitory activity of 90.5% against Huperzine A and surpassed the positive control Listigmine(89.6%), which was a commercial AChE inhibitor with carbamate. The activity of N, N-dimethyl substituted product of 3-isopropyl-5-cresol was evidently higher than its N-methyl substituted product, whose inhibition efficiency reached 97.9% of Huperzine A. The relationship between the concentration and the inhibition rate showed that 3-isopropyl-5-methylphenyl-N, N-dimethylcarbamate(Ⅰ-2) had a substantially equivalent AChE inhibitory activity to Huperzine A when the concentration was greater than 1.25 mmol/L, indicating that it had the potential to be developed as a therapeutic drug for Alzheimer's disease or insecticide. Figures and Tables | References | Related Articles | Metrics

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The Relationship Between Pore Size Distribution and Adsorption Properties of Cumaru Activated Carbon Prepared by Phosphoric Acid Method Mingzhe MA, Hao SUN, Kang SUN, Mengmeng FAN, Yanping ZHANG, Jianchun JIANG 2023, 43 (1):  51-56.  doi: 10.3969/j.issn.0253-2417.2023.01.006 Abstract ( 248 )   HTML ( 207 )   PDF (504KB) ( 284 )   Save The influences of phosphoric acid method activation temperature, phosphoric acid concentration and impregnation ratio on adsorption performance of cumaru activated carbon were investigated by using the processing the residue of hardwood cumaru as a raw material. Structural analysis of activated carbon was analyzed by N2 adsorption-desorption isotherm, and the structure-activity relationship between the effective pore volume and the liquid phase adsorption results(iodine adsorption value, methylene blue adsorption value and caramel decolorization rate) were calculated according to the adsorption theory and DFT pore size distribution map. The results showed that the synthesized activated carbon exhibited excellent adsorption properties and pore structure under the conditions of 60% phosphoric acid solution, the impregnation ratio of phosphoric acid to cumaru 3∶1(mL∶g), the activation temperature of 500 ℃ and the activation time of 120 min. Its iodine value, methylene blue value, caramel decolorization, specific surface area, and total pore volume were 841 mg/g, 270 mg/g, 120%, 1 516 m2/g and 1.145 cm3/g, respectively. These properties were comprehensively superior to those of the activated carbon prepared from the residues of soft wood fir. The corresponding pore volume of different pore size distributions was calculated for cumaru activated carbon using the Density Functional Theory(DFT). After theoretical analysis and fitting calculation, it was found that there was a good linear relationship between iodine adsorption value and pore volume with pore diameter of 1.0-2.7 nm, between methylene blue adsorption value and pore volume with pore diameter of 1.7-5.0 nm, and between caramel decolorization rate and pore volume with pore diameter of 2.7-6.3 nm. These results indicated a good degree of association(R2>0.95) between the pore structure distribution of activated carbon and its liquid phase adsorbing performance. Figures and Tables | References | Related Articles | Metrics

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Preparation and Performance Study of Degradable Turpentine-based Polymer Materials Songlin DAI, Yazhou XU, Huiru MA, Haibo ZHANG, Zhendong ZHAO, Yuxiang CHEN 2023, 43 (1):  57-62.  doi: 10.3969/j.issn.0253-2417.2023.01.007 Abstract ( 193 )   HTML ( 102 )   PDF (1089KB) ( 276 )   Save A bio-based polymer material FMDA-ESO containing ester and D-A bonds was synthesized from epoxidized soybean oil(ESO), N, N'-(difuranyl)-1, 8-p-menthane diamine(FMDA), maleimidic caproic acid and adipic acid. The materials were characterized and tested by Fourier transform infrared spectroscopy(FT-IR), differential scanning calorimetry(DSC), thermogravimetric analysis(TG) and universal test tester. The results showed that the cross-linked structure was formed in FMDA-ESO with the presence of ester and D-A bonds, and the rigid structure of FMDA could improve the mechanical properties of the obtained materials. With the amount increasement of FMDA in the FMDA-ESO cured formulation, the thermal stability of the material increased. Rapid degradation of FMDA-ESO could be achieved in the presence of ethanolamine, which could be degraded to oligomers with a number-average molecular weight of 2 691 at 135 ℃ for 30 min. Figures and Tables | References | Related Articles | Metrics

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Carbon Stable Isotope Fractionation of 5-Hydroxymethylfurfural from Hydrothermal Liquefaction Qin CHENG, Juanzhang SHEN, Yanyan CAI, Jun YE, Ziyang WU, Weihong TAN 2023, 43 (1):  63-71.  doi: 10.3969/j.issn.0253-2417.2023.01.008 Abstract ( 175 )   HTML ( 127 )   PDF (663KB) ( 286 )   Save In this work, the carbon isotopic fractionation characteristics of feedstocks with different stable carbon isotopic compositions during hydrothermal liquefaction for preparation of 5-hydroxymethylfurfural(5-HMF) were compared, and the effect of carbon stable isotope composition of raw materials on the yield of 5-HMF was studied. The results showed that the maximum yield of tapioca starch was 33.90%, which is higher than those of corn starch(29.93%), poplar cellulose(P-C, 31.00%), and corn straw cellulose(CS-C, 30.76%), respectively. The maximum yields of bamboo flour and poplar were 13.00% and 13.80%, which were higher than those of corn straw(11.6%) and corn cob(12.53%), respectively. At the reaction time of 15 min, the reaction rate of different raw materials: tapioca starch 0.301 g/(L·min) was greater than corn starch 0.128 g/(L·min), poplar cellulose 0.513 g/(L·min) was greater than corn straw cellulose 0.386 g/(L·min), and bamboo powder 0.133 g/(L·min) was greater than poplar 0.124 g/(L·min), which was greater than corn cob 0.117 g/(L·min) and greater than corn straw 0.097 g/(L·min). In the reaction process, the change rate of δ13C value of raw materials with smaller δ13C value(cassava starch, poplar cellulose, poplar and bamboo powder) in the initial stage of reaction was greater than that of raw materials with larger δ13C value(corn starch, corn straw cellulose, corn straw and corn cob). There was a stable isotope kinetic effect in the hydrothermal liquefaction process. The 13C isotope required more energy to participate than the enriched raw materials in the reaction, the reaction rate was slow, and the yield of 5-HMF was low. In the process of liquefaction, the stable isotope fractionation of raw material with a simple structure has a great influence. The greater degree of liquefaction, the greater degree of change of δ13C. Figures and Tables | References | Related Articles | Metrics

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The Application of Capacitive Deionization Technology Based on Activated Carbon Electrode to Produce Pure Water Chang TAN, Bei LI, Ao WANG, Xiaojing LIU, Dongrui YAO, Kang SUN 2023, 43 (1):  72-78.  doi: 10.3969/j.issn.0253-2417.2023.01.009 Abstract ( 199 )   HTML ( 155 )   PDF (1967KB) ( 290 )   Save Capacitive deionization(CDI) was emerging as a technology with low-energy consumption in treating brackish water. The feasibility of CDI technology based on carbon electrodes in producing pure water was investigated in this work. A self-designed CDI desalination system was constructed with activated carbon electrodes, graphite current collector, plexiglass spacer, etc. The desalination capacity, energy consumption, salt removal rate, ion interception rate, water recovery and stability of the CDI system were explored by using urban tap water as the feed. The results showed that the specific surface area of Activated carbon was 1 586 m2/g, average pore diameter was 2.08 nm, and total pore volume was 0.82 cm3/g. XPS showed that the carbon, oxygen and nitrogen contents of the activated carbon were 94.81%, 4.10% and 1.09%, respectively, which contained a small amounts of oxygen- and nitrogen functional groups on the surface. The CDI system could produce pure water with ion concentration of 0.06 mmol/L and total dissolved solids(TDS) lower than 5 mg/L, while the energy consumption was only 0.115 5 kWh/m3 and the overall salt removal rate reached 98.1%. The ion rejection rates of various ions were ranging from 78.6% to 99.8%, and the water recovery was 80%. Furthermore, the desalination performance of the electrode remained stable and the cycle performance was good after 42 adsorption-desorption cycles. Figures and Tables | References | Related Articles | Metrics

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Extraction, Isolation and Structure Identification of Pigment Compounds from Ginkgo biloba Leaves Hong SHEN, Changwei ZHANG, Hongxia CHEN, Ran TAO, Jianxin JIANG, Chengzhang WANG 2023, 43 (1):  79-88.  doi: 10.3969/j.issn.0253-2417.2023.01.010 Abstract ( 219 )   HTML ( 85 )   PDF (813KB) ( 324 )   Save Ethanol extracts of three samples were prepared from Ginkgo biloba L. fresh leaves(sample 1), dry leaves(sample 2) and old leaves(sample 3). HPLC-DAD-MS method was used to analyze the pigment compounds in three G. biloba leaves samples. The separation, purification and structure identification of ginkgo leaf pigment compounds in sample 2 and sample 3 were conducted by liquid-liquid extraction, silica gel column chromatography, HPLC preparative chromatography, etc. From the three samples, 24 kinds of pigment compounds in G. biloba leaves were preliminarily speculated, including 17 kinds of chlorophyll compounds and 7 kinds of carotenoid compounds. Ten monomer pigment compounds in G. biloba leaves were isolated and purified from ethanol extract of sample 2 and sample 3. They were identified as β-carotene (A), pheophytin a (B), pheophytin b (C), lutein (D), phy-purpurin 18a (E), pyropheophytin a (F), 132-OH-pheophytin a (G), 132-OH-pheophytin a' (H), 132-OH-pheophytin b (I), and 132-OH-pheophytin b' (J), respectively, by mass spectrometry, ultraviolet spectroscopy, infrared spectroscopy and proton nuclear magnetic resonance spectroscopy combined with literature comparison. Among them, E, F, G, H, I and J were isolated from G. biloba leaves for the first time. Figures and Tables | References | Related Articles | Metrics

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Modification and Characterization of Alkali Lignin by Choline-chloride/Lactic Acid Deep Eutectic Solvents Catalyzed by Sodium Carbonate Qingye LIU, Xianyun CHEN, Hua DENG, Weixing GAN, Siyu HUANG, Mianwu MENG 2023, 43 (1):  89-96.  doi: 10.3969/j.issn.0253-2417.2023.01.011 Abstract ( 220 )   HTML ( 166 )   PDF (810KB) ( 274 )   Save The deep eutectic solvents(DES) were synthesized by choline chloride(ChCl) and lactic acid(Lac), urea(U), oxalic acid(OA) and formic acid(FA), respectively. The industrial alkali lignin(AL) was modified by these DESs. The effects of different DES systems, reaction conditions and catalysts on the extraction yield of the modified alkali lignin were studied. It was found that the extraction yield of lignin was the highest when ChCl/Lac was used. The optimal conditions of ChCl/Lac modification were obtained by single factor test. And the optimal conditions were 120 ℃, the mole ratio of Lac to ChCl(nLac/nChCl) 12 ∶ 1, mass ratio of DES to alkali lignin (mDES/mAL) 20 and reaction time 12 h, under these conditions, the extraction yield of lignin was 95.37%. When the reaction temperature was reduced to 100 ℃, the lignin extraction yield was 40.39% without catalyst. While 8% sodium carbonate was used as catalyst, the lignin extraction yield increased to 74.87%. The lignin samples were characterized by FT-IR, 13C NMR, TG and DTG. The results of FT-IR and 13C NMR showed that β-O-4 bond was broken and hydroxymethyl and methoxyl groups were introduced during modification, and the modified lignin was mainly composed of syringyl unit. From TG and DTG results, the exothermic peak of lignin moved to high temperature after sodium carbonate catalytic modification, and the thermal stability was improved. Figures and Tables | References | Related Articles | Metrics

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Quantification and Antioxidant Activity of Flavonoids in Bamboo Leaves Extract of Bambusa Rongmiao AN, Ting YUAN, Xuefeng GUO 2023, 43 (1):  97-103.  doi: 10.3969/j.issn.0253-2417.2023.01.012 Abstract ( 535 )   HTML ( 254 )   PDF (504KB) ( 335 )   Save To explore the development and utilization of flavonoids in the leaves of the main bamboo species of Bambusa, extracts of leaves from ten bamboo species were obtained by extraction, separation and purification, using bamboo leaves from Bambusa as the materials. A HPLC method was established for the determination of 5 flavonoids in extract of bamboo leaves, and the antioxidant activities of those extracts were evaluated by DPPH and ABTS assays. The HPLC method for the determination of 5 flavonoids isoorientin, orientin, vitexin, isovitexin and luteoside in extract of bamboo leaves was using YMC-Pack ODS-A column(250 mm×4.6 mm, 5 μm) with 0.5% acetic acid/water(A) and acetonitrile(B) as the mobile phases, elution with 14% B for 40 min, the injection volume 10 μL, the flow rate 1 mL/min, the column temperature 30 ℃ and the detection wavelength at 340 nm. Under these conditions, the five flavonoids were completely separated within 40 min, the degree of separation was greater than 1.2, and the concentration had a good linear correlation with the peak area(R2>0.999). The recovery rate was 94.36%-105.37%, and the relative standard deviation(RSD) was 0.98%-3.48%. These results indicated that the method was stable and reliable. The total contents of 5 flavonoids in extract of leaves from 10 bamboo species of Bambusa measured under these conditions were 62.30-223.24 mg/g, and the mass fraction of bamboo leaves extract from B. multiplex f. fernleaf was the highest(223.24 mg/g). The half inhibitory mass fraction(IC50) values of DPPH· and ·ABTS+ were 28.58-44.37 mg/L and 8.58-11.07 mg/L, respectively, slightly higher than those of Vc and BHT. The bamboo species with better DPPH· scavenging rate were B. eutuldoides (IC50=28.58 mg/L), B. textilis (IC50=28.68 mg/L) and B. multiplex f. fernleaf (IC50=31.65 mg/L). The bamboo species with better ABTS·+ scavenging rate were B. multiplex f. fernleaf(IC50=8.58 mg/L), B. multiplex f. silverstripe(IC50=9.11 mg/L) and B. textilis (IC50=9.27 mg/L). The IC50 values of B. multiplex f. fernleaf and B. textilis of two kinds of radicals were lower, which were the two bamboo species with the best removal effect and the most value of development and utilization. Figures and Tables | References | Related Articles | Metrics

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Preparation of Different Purity Indigo Extracts and Study of Their Antibacterial Activities Yangyang YAN, Changwei ZHANG, Chuan LI, Hao ZHOU, Chengzhang WANG 2023, 43 (1):  104-112.  doi: 10.3969/j.issn.0253-2417.2023.01.013 Abstract ( 281 )   HTML ( 373 )   PDF (608KB) ( 323 )   Save On the basis of establishing the analysis method of indigo content, a new and efficient method for the preparation of indigo with high purity was established, and the antibacterial activities of different crude indigo extracts and high purity indigo were studied. Using Baphicacanthus cusia leaves as raw material, three crude extracts samples 1-3 with different indigo mass fractions(3.06%, 20.13%, 22.16%) were obtained by water extraction, stir with alkali, acid neutralization and sodium hydroxide for impurity removal. On this basis, single factor test and Box-Behnken response surface design method were used to optimize glucose reduction process for acquiring high purity of indigo sample 4. Finally, oxford cup method was employed to compare the antibacterial activities of three kinds of crude indigo extracts and high purity indigo against Aspergillus niger, Staphylococcus aureus and Escherichia coli. Results showed that the optimal conditions of glucose reduction were glucose concentration of 25 g/L, sodium hydroxide concentration of 26.9 g/L, reaction temperature of 60 ℃ and reaction time of 30 min. Under the optimum conditions, the purity of indigo could reach 96.87%(sample 4), and the yield of indigo was 76.88%. Results of bacteriostatic experiment demonstrated that the three kinds of indigo crude extracts and high purity indigo had inhibitory effect on A. niger, S. aureus and E. coli, and the inhibitory effects on the three kinds of bacteria increased with the increase of the mass fraction of indigo in the samples. Moreover, the inhibition zone diameter, MBC values, MIC values and IC50 values of these extracts were 9.00-19.69 mm, 1-512 mg/L, 8-64 mg/L(A. niger) and 0.6-448 mg/L, respectively. The high purity indigo had a good inhibitory effect on A. niger, and its MIC, MBC and IC50 values were 1, 8 and 0.6 mg/L, respectively. Figures and Tables | References | Related Articles | Metrics

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Synthesis of Terpineol from α-Pinene Catalyzed by Triple Acid Composite System Zhonglei MENG, Yiming HU, Rusi WEN, Rongxiu QIN, Yonghong ZHOU 2023, 43 (1):  113-119.  doi: 10.3969/j.issn.0253-2417.2023.01.014 Abstract ( 161 )   HTML ( 268 )   PDF (597KB) ( 258 )   Save The triple acid catalyst system composed of α-hydroxycarboxylic acid represented by citric acid, phosphoric acid and low carbon chain fatty acid represented by propionic acid was applied to the catalytic hydration of α-pinene to synthesize terpineol. The effects of solvent type, fatty acid chain length, α-hydroxycarboxylic acid type, catalyst amount, water amount, reaction temperature and reaction time on the hydration reaction were investigated. The results showed that under the reaction conditions of the mass ratio of α-pinene, water, propionic acid, citric acid and phosphoric acid of 1∶1∶2∶0.05∶0.1, reaction temperature of 70 ℃ and reaction time of 24 h, the conversion of α-pinene, the GC content of terpineol and the product selectivity could reach 99.0%, 53.3% and 54.9%, respectively. Under the same conditions, the selectivity of the target product terpineol could be improved by adding the monocyclic monoterpene by-products generated during the hydration of α-pinene to the starting material. When the addition amount was 40%, the selectivity of terpineol could be increased to 76%. The product composition analysis showed that the total GC content of terpineol in the product was 53.3%, the total GC content of hydrate was 57.1%, and the total content of propionate was 8.1%. Figures and Tables | References | Related Articles | Metrics

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Chemical Constituents Analysis and Process Optimization of Ethanol Extract from Mulberry Leaves Jia FU, Yujian WU, Zhiming LIU, Haiying WANG 2023, 43 (1):  120-126.  doi: 10.3969/j.issn.0253-2417.2023.01.015 Abstract ( 206 )   HTML ( 309 )   PDF (1182KB) ( 329 )   Save The components of absolute ethanol and 70%(volume fraction) ethanol extracts of mulberry leaves were analyzed by GC-MS. On this basis, taking the yield of mulberry leaf extract as the index, the effects of ethanol volume fraction, extraction temperature and extraction time on the yield of mulberry leaf ethanol extract were investigated, and the extraction process of mulberry leaf ethanol water bath heating extract was optimized by response surface methodology. The results showed that 9 kinds of substances were identified in the absolute ethanol extract of mulberry leaves, and 19 kinds of substances were identified in 70% ethanol extract. From high to low, the organic matter contents in anhydrous ethanol extract were alcohols of 24.78%, aromatics of 24.57%, alkanes of 23.72% and aminourea of 0.68%. The compound with the highest content was α, β-dimethyl phenylethanol(24.78%). The organic matter content in 70% ethanol extract was composed of esters(32.99%), alkanes(24.35%), ketones(9.57%), acids(7.07%), nitriles(0.52%) and alcohols(0.45%) from high to low. The compound with the highest content was benzoic acid-2, 5-bis(trimethylsiloxy)-trimethylsilyl ester(20.01%). The optimum extraction conditions of ethanol extract from mulberry leaves were 5 g of mulberry leaf powder, 50 mL of ethanol solution, ethanol volume fraction of 66%, extraction temperature of 85 ℃ and extraction time of 182 min. Under these conditions, the yield of ethanol extract from mulberry leaves was 20.0%. Figures and Tables | References | Related Articles | Metrics

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Preparation, Characterization and Adsorption Properties of Nitrogen-doped Lignin-based Activated Carbon Jiewang YE, Zhidan ZHOU, Zhenfu JIN 2023, 43 (1):  127-132.  doi: 10.3969/j.issn.0253-2417.2023.01.016 Abstract ( 256 )   HTML ( 351 )   PDF (2843KB) ( 319 )   Save The introduction of nitrogen functional groups on carbon materials can effectively improve carbon materials for dye adsorption performance.We used alkali lignin(AL) as raw material, KOH as an activator, chitosan(CS) for nitrogen source to prepare nitrogen-doped lignin-based activated carbon(N-LAC), the performance of activated carbon was characterized by SEM, XPS and N2 adsorption-desorption experiments. Experimental results show that N-LAC is dominated by micropore, and nitrogen addition increases the surface porosity of activated carbon. When the preparation conditions are KOH to alkali lignin ratio of 2∶1, account for 30% of chitosan(alkali lignin mass fraction ratio), activation temperature of 800 ℃, and activation time of 2 h, specific surface area is 1 457.79 m2/g, total pore volume is 0.789 cm3/g, micropore volume is 0.612 cm3/g, and average pore size is 2.165 nm. Nitrogen is mainly in the forms of pyrrole nitrogen(N-5) and pyridine nitrogen(N-6), and the doping of nitrogen will reduce the graphitization degree of activated carbon. The N-LAC was applied to the adsorption experiments of methyl orange(MO) and methylene blue(MB), and the adsorption kinetics showed that, N-LAC adsorbed MO according to the intra-particle diffusion model, mainly based on surface adsorption; N-LAC adsorbed MB according to the quasi-second-order kinetic model. Figures and Tables | References | Related Articles | Metrics

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Comparison on Enzymatic Activity, Polysaccharide Structure and Rheological Properties of Gleditsia sinensis Lam. Seeds During Germination Yingying PEI, Wei XU, Xinfeiran PEI, Jiufang DUAN, Diansong CHEN, Jianxin JIANG 2023, 43 (1):  133-139.  doi: 10.3969/j.issn.0253-2417.2023.01.017 Abstract ( 186 )   HTML ( 299 )   PDF (659KB) ( 270 )   Save The germination process of Gleditsia sinensis seeds was simulated at 25 and 35 ℃, respectively. The activity of α-D-galactosidase in cotyledon and endosperm, the molecular weight, monosaccharide content and rheological properties of G. sinensis galactomannan were studied at different germination times. The results showed that at 25 ℃, the activity of α-D-galactosidase in the endosperm of G. sinensis fluctuated from 3.45 to 5.78 U/g(2-8 days after germination), and then rapidly increased to 86.12 U/g(14 days after germination). At 35 ℃, the activity of α-D-galactosidase in the endosperm of G. sinensis fluctuated from 3.31 to 9.24 U/g. The α-D-galactosidase enzyme activity in cotyledon of G. sinensis was higher than that in endosperm. At the early germination stage, the higher germination temperature(35 ℃) was more conductive to the degradation of galactomannan. With the prolongation of germination time, the molecular mass and viscosity of G. sinensis galactomannan gradually decreased, and the solution changed from pseudoplastic fluid to Newtonian fluid on day 12 at 25 ℃. The contents of mannose and galactose in G. sinensis galactomannan decreased gradually with the extension of germination time, and the mass ratio of mannose to galactomannan(M/G value) increased gradually. The M/G reached the maximum value of 3.31 on the 14th day of germination at 35 ℃, which was expected to be a substitute product for expensive locust bean gum galactomannan. Figures and Tables | References | Related Articles | Metrics

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A Review on Recent Advances in Catalytic Conversion of Biomass for Selective Production of Bio-aviation Fuels Yunwu ZHENG, Jida WANG, Donghua LI, Can LIU, Zhangshuai DING, Zhifeng ZHENG 2023, 43 (1):  140-154.  doi: 10.3969/j.issn.0253-2417.2023.01.018 Abstract ( 317 )   HTML ( 408 )   PDF (1049KB) ( 379 )   Save Catalytic conversion of biomass was the main route to produce high quality bio-based aviation fuel and solve energy crisis. In this paper, according to the perspective of the existing preparation methods of bio-aviation fuel, the technical routes and catalytic systems required by different feedstocks and the catalysts used in different technical routes were summarized from the perspective of raw materials adapted to the demand(oil, lignocellulose biomass and sugar raw materials) and technical routes(hydrodeoxygenation, Fischer-Tropsch synthesis, aldol condensation and olefin oligomerization). At the same time, the reaction conditions and reaction mechanism were also reported. It was pointed out that the critical problems in catalytic conversion process, including higher cost, complex process and conversion mechanism(high temperature and high pressure), higher H2 consumption, poor selectivity of desired target products and deactivation of catalyst. Finally, according to the advantages and disadvantages of various raw materials and technical routes as well as the problems faced, some suggestions were proposed and the future development direction was prospected. Figures and Tables | References | Related Articles | Metrics