An anti-freezing hydrogel electrolyte(SPI-PVA-PAAm/LiCl) was synthesized, in which soybean protein isolates (SPI), ployvinyl alcohol(PVA) and acrylamide(AAm) were used as raw materials, ammonium persulfate(APS) was used as the initiator, N, N'-methylenebisacrylamide(MBAA) was used as the covalent crosslinker, LiCl was used as the electrolyte salt, and N, N, N', N'-tetramethylethylenediamine(TEMED) was used as the accelerator. Under low temperature conditions, the mechanical properties of the hydrogel electrolyte were analyzed, and the electrochemical properties of the solid-state supercapacitor based on this hydrogel electrolyte were investigated. The results showed that the hydrogel electrolyte had excellent anti-freezing propertity, because a certain molar concentration of LiCl reduced the freezing point of pure water in the hydrogel electrolyte and inhibited the crystallization behavior of water molecules. When the environmental temperature was reduced from 25℃ to -20℃, the hydrogel electrolyte still showed good mechanical properties and ionic conductivity. With the increase of the amount of LiCl, the compression performance of the hydrogel electrolyte firstly increased and then decreased, and the ionic conductivity increased. After 10 cycles of 80% compression strain, the stress retention rate, plastic deformation rate and energy loss coefficient of the hydrogel electrolyte with LiCl concentration of 5 mol/L(S-Li-5) were more than 100%, less than 25% and 0.33, respectively. The hydrogel electrolyte with LiCl concentration of 15 mol/L(S-Li-15) and CNTs were used to assemble the solid supercapacitor whose electrochemical performance was evaluated. When the ambient temperature was reduced from 25℃ to -20℃, the specific capacitance of assembled supercapacitor calculated by GCD curve could be maintained above 80%, and 0-70% compression strain could be withstood without damage, and the supercapacitor could still work normally; In addition, when the current density was 8.12 A/g, the capacitance retention rate of the device was higher than 91% after 1 000 cycles at -20℃.
Lignin is the most abundant renewable aromatic polymer in nature, which complex structure and compact connection with cellulose and hemicellulose through covalent bond and hydrogen bond make it difficult to be separated efficiently. Deep eutectic solvents (DES) is a novel kind of green ionic liquid, which has been successfully applied to lignin isolation due to its unique physical and chemical properties. The research progress of dissolution and extraction of lignin by deep eutectic solvents (DES) is reviewed in detail. From the point of view of the mechanism of dissolving lignin by DES, the effects of different factors(composition, proportion, pH value, functional groups of DES, water content of system, raw material, reaction time, temperature, catalyst, co-solvent, and so on) on lignin removal were emphatically expounded. Based on the research progress of DES in lignin extraction, the research progress and futuer application of lignin extraction were summarized and prospected.
The consumption of wood adhesive in China is huge. However, the main wood adhesive based on formaldehyde is still prevalent. In recent years, environment friendly adhesives such as non-formaldehyde adhesives and biomass adhesives have developed rapidly. Herein, the recent research and application of wood adhesives including urea-formaldehyde resin adhesives, phenolic resin adhesives, melamine-formaldehyde resin adhesives, protein adhesives, lignin adhesives, starch adhesives, tannins adhesives, isocyanate adhesive, emulsion adhesives and pyrolysis biological oil adhesives were reviewed. The development trend and the research direction of wood adhesives were also prospected.
The hydrophilic, ductile, thermoplastic and biodegradable properties of cellulose acetate (CA) were introduced, and the basic structure and market application of three kinds of cellulose acetate were summarized.It was pointed out that CA still had some disadvantages such as poor thermal stability at high temperature, low mechanical strength and easily being contaminated. The impacts of the physical modification and chemical modification on the properties of CA were also reassessed.It could conclude that the chemical reaction with polymer could change the structure or properties of CA.The fouling resistance, thermoplastic, selective and reuse of the CA were improved greatly, while the physical modification could improve the porosity and thermal stability of CA membrane, and the membrane mechanical strength, metal ion exclusion rate and the water flux were improved. The applications of CA in seawater desalination, adsorption of toxic substances in flue gas, preparation of biomedical membrane, drug delivery, tissue repair and regeneration, biosensor, outdoor protection and air purification were also summarized, and the market prospect and development trend of CA were prospected.
The mechanism of 5-hydroxymethylfurfural(5-HMF) pyrolysis was studied by density functional theory B3LYP/6-31G++(d, p). The results show that the energy barrier of generating furfural by hydroxy side chain removal of 5-HMF is 322.8 kJ/mol, and the energy barrier of 2-furfuryl alcohol by aldehyde group side chain removal of 5-HMF is 375.4 kJ/mol. It is indicated that the appearance of furfuryl is earlier than 2-furfural in the pyrolysis process of 5-HMF. Further pyrolysis of furfural can occur the ring-opening reaction to form benzene ring with the reaction energy barrier of 370.8 kJ/mol, which explains that the furan ring can undergo deoxygenation and cyclization reaction. 5-HMF can directly generate ring-opening reaction in the case of H2O participation or without H2O participation to obtain enol compounds or enone compounds. The energy barrier of ring-opening reaction with H2O participation is 287.6 kJ/mol, and the energy barrier of ring-opening reaction without H2O participation is 279.1 kJ/mol. Thus, the participation of water molecules is not conducive to the ring opening of 5-HMF.
Anthocyanin is a kind of flavonoid which mainly exists in plants. It has strong biological activities such as anti-cancer and anti-oxidation, and is widely used in the field of nutrition and health care. Most anthocyanins are extracted directly from plants by physical or chemical means, but the yield is low, and the extracted anthocyanins are mostly mixtures due to the restrictions of time, region and season. Biosynthesis of anthocyanins have attracted much attention by researchers worldwide in recent years. As the biosynthesis of anthocyanins can be controlled artificially and the purity of the obtained products is high, it has been widely studied. Anthocyanins cannot exist stably in the environment, and need to be modified by glycosylation, acylation and methylation to increase their stability. The modified anthocyanins can be synthesized by microorganisms and significant color changes can be seen in the medium. The biosynthesis and modification of anthocyanins were reviewed in this paper, and the preparation technology of anthocyanin synthesis from plants and microorganisms was briefly introduced, the factors affecting anthocyanin synthesis were analyzed, and finally the future research direction of anthocyanin was predicted.
Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometer(UHPLC-QTOF MS) was applied to scan the main chemical constituents of distillation residues from cinnamon twigs and leaves. The molecular ion and characteristic fragment ions were detected in positive and negative ion modes. The fragmentation pathways of compounds were studied. The chemical constituents were characterized comprehensively by high resolution data and fragmentation of mass spectrometry. The results showed that UHPLC-QTOF MS can be used for rapid and comprehensive qualitative analysis of the chemical constituents from distillation residues. Total of 26 components of the residues were identified, including 2 polyphenols, 3 flavonoids, 5 glycosides, 4 alcohols, 3 aldehydes and 9 acids.
The cellulose dissolution capability and dissolution mechanism of current novel solvent systems, including aqueous solvent systems (NaOH aqueous solution, alkali/urea and NaOH/thiourea aqueous solution, quaternary ammonium/phosphine aqueous solution, and molten inorganic salt hydrates) and organic solvent systems (LiCl/N, N-dimethylacetamide, ionic liquids and deep eutectic solvents) were reviewed. Sequentially, the advantages and disadvantages of various solvents were discussed, which could provided a reference for the future development and utilization of green cellulose solvents.
The bioactive compounds were extracted from cinnamon distillation residue(CR) by using ultrasonic-assisted extraction technology, and the extract were further purificated with AB-8 macro porous resin. The contents of total flavonoid and polyphenol were measured by UV spectrophotometer, and the contents of six main components were detected by HPLC. The antioxidant properties of the extract were evaluated. The results showed that the contents of flavonoid and polyphenol in the sample were increased by about 2.6-4.2 times after elution with 80% ethanol. The contents of flavonoid extracted from the residues of leaves (LR), twigs (TR) and barks (BR) were 18.50%, 53.93% and 44.48%, and the contents of polyphenol were 2.60%, 37.56% and 28.16%, respectively. The components with the maximum content in LR, TR and BR extracts were coumarin or cinnamic acid. The contents of the six main components in the extracts of LR, TR and BR were significantly different and decreased in the following order TR > BR > LR. The total antioxidant capacities of TR and BR extracts were 8.12 and 7.5 U/mL. The IC50 value of the scavenging effects on DPPH·of TR, BR and LR extracts were 0.017, 0.021 and 0.150 g/L, respectively. The IC50 of the scavenging effects on·OH of TR extracts was 0.12 g/L. TR and BR have good total antioxidant capacity and the scavenging effects on DPPH· and·OH. LR extracts have relatively weak antioxidant capacity.
As a natural material with good biocompatibility and biodegradability, nano-cellulose has unique structure and excellent mechanical properties. It has been widely used in the construction of electrochemical energy storage system of lithium-ion batteries(LIBs), and has made significant progress. This thesis provided an overview of the preparation and modification methods of cellulose nanofibrils(CNF), cellulose nanocrystals(CNC) and bacterial cellulose(BC) in the context of the application of advanced energy storage devices LIBs and green materials nanocellulose, and reviewed the research progress on the application of nanocellulose in the field of LIBs. It was mainly divided into three aspects: first, nanocellulose-based flexible LIBs electrodes; second, carbon materials derived from nano cellulose as electrodes; third, nano cellulose derived battery separator. Finally, some problems in this field were analyzed, summarized and prospected.
Steam activated carbon (AC) was prepared by using coconut shell as raw material, followed by using hydrothermal method and ethanol and water as solvent to prepare capacitance super-capacitor (GAC1-GAC5) with the mass ratios of AC and graphene(GR) 90:0, 90:5, 90:54, 90:90 and 54:90. By nitrogen adsorption-desorption, XRD and SEM methods, the pore structure and surface morphology of activated carbon were characterized. Comparison of different composite capacitance ratio super-capacitor electrode material was analyzed by cyclic voltammetry(CV), galvanostatic charge-discharge(GCD) method. The experimental results showed that the specific surface area of coconut shell activated carbon was 2 482 m2/g, and its pore diameter was mainly distributed at 2-4 nm, with the pore volume as 1.33 cm3/g, specific capacitance was 85 F/g in 6 mol/L KOH electrolyte. Under the conditions of carbonization temperature of 800℃, activation temperature of 900℃ and activation time of 1.5 h, the addition of the graphite improved the composite material capacitance up to 186 F/g.
In this paper, the principle, preparation and influencing factors of bamboo-based supercapacitor materials are mainly introduced, as well as the research progress in the structural design and technical studies. Comparing to the single activated bamboo-carbon, bamboo-based carbon composites, taking bamboo-carbon as the template for the growth/fitting of pseudo-capacitance materials, are emphatically discussed. The redox reaction at the interface between the pseudo-capacitance material and the electrolyte results in the additional pseudo-capacitance, significantly improving the electrical performance of bamboo-based carbon materials and then extending the area of its applications. Finally, the perspective of the abundant bamboo resources in the field of supercapacitors is prospected, basing on the summary of current research progress and facing problems.
Eucommia ulmoides Oliv. seed oil liposomes were prepared by a combined technology of ethanol injection and ultrasound, and the stability of liposomes was also evaluated. The optimized conditions and the encapsulation efficiency of E. ulmoides seed oil liposomes were investigated by Plackett-Burman design, the steepest ascent design and response surface methodology.The results showed that the optimal conditions selected were as follows:the mass ratio of phosphatidylcholine to sitosterol (X1)3.1:1, the mass ratio of phosphatidylcholine to E. ulmoides seed oil (X2) 4:1, dosage of tween-80(X3) 20%, phosphate buffer solution pH value (X4) 6.9, ultrasonic time (X5) 13 min, ultrasonic power (X6) 180 W. Under this condition, the actual encapsulation efficiency, average particle size, average potential and poly dispersity index (PDI) of E. ulmoides seed oil liposomes were 75.26%, 137.4 nm, -19.3 mV and 0.219, respectively. The particles showed irregular oval shape and smooth and complete morphology via the transmission electron microscopy observation. The stability experiments showed that E. ulmoides seed oil liposomes were significantly affected by the temperature, and the stability of all indexes at 4℃ was better than that at 25℃ and 40℃.When the E. ulmoides seed oil liposomes were stored at 4℃ for 15 days, the encapsulation efficiency decreased from 75.26% to 61.45%, the pH value decreased slightly, the average particle size increased from 137.4 nm to 160.9 nm, and malondialdehyde (MDA) increased from 0.023 2 mg/g to 0.033 1 mg/g.
To deeply understand the catalytic mechanism of bio-char on volatiles during biomass pyrolysis, a variety of functionalized graphenes, including RGO-OH, RGO-COOH and RGO-NH2, were used as functional-group-rich char models. The catalytic effect of these different surface functional groups on the typical lignin α-O-4 compound benzyl phenyl ether(BPE) at 400℃ was investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results showed that -OH and -COOH significantly increased the degree of thermal decomposition of BPE. The conversion of BPE increased from 0.1% (without catalyst) to 37.73% (with RGO-COOH as catalyst) and 53.78% (with RGO-OH as catalyst), respectively. However, -NH2 only provided a BPE conversion of 12.29%, even weaker than the catalytic activity of non-functionalized reductive graphene oxide (RGO) (BPE conversion of 25.63%), indicating that the RGO as carrier also had a certain catalytic effect on BPE conversion, and -NH2 played an inhibitory role. The decomposition of BPE was mainly caused by the sp3 Cα-O bond cleavage, and the proudcts were mainly phenol and 2-benzylphenol. The surface oxygen-containing functional groups (-OH and -COOH) promoted the dimerization reaction, forming 2-benzylphenol and 4-benzylphenol. In addition, the functional groups also could promote the cleavage of sp2 Caryl-O, and the main product was benzaldehyde.
Urushiol was used as raw material, through etherification of o-diphenol hydroxyl group, introducing isoxamic acid group into the tail of side chain, and functional groups of nitro, hydroxyl group into benzene ring or aliphatic chain. Three novel methylene ether urushiol hydroxamic acid derivatives were synthesized. The structure of the synthesized compounds was characterized by means of 1H NMR, 13 C NMR and MS analysis. The interaction mode between the compounds and HDAC 2 was studied by molecular docking. The results showed that three compounds could bind to the active pocket of HDAC 2 and interact with the residues of His145, Tyr 308, Glu103 and Asp104 to form hydrogen bonds. It could form stable chelation with Zn2+ at the bottom of active pocket. The inhibitory activity of compounds on HDAC 2 was detected by kit AK-501. The results showed that the inhibitory effects of compound 2 and 3 on HDAC 2 were better than that of compound 1, and the IC50 values of compound 2 and 3 were similar to that of SAHA(IC50=0.20 mg/L), the half inhibitory concentrations (IC50) of compounds 1, 2 and 3 on HDAC2 were 0.33, 0.29 and 0.24 mg/L, respectively.
The porous SiO2@C composites were fabricated via a one-step in situ doping approach using biomass waste larch sawdust as raw material and SiO2 as pore structure regulator. The effects of different carbonization temperature and SiO2 as the template on pore structure and adsorption property of composites were investigated.The SEM, TEM, nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were adopted to characterize the composite material. Meanwhile, the adsorption behavior of the composites was studied by using ethyl violet dye as the model. The results showed that the morphologies of SiO2@C composites obtained from carbonization between 700 to 900℃ changed from cross-linked spherical to network-like structure, and the porous structures changed from disorder to order.Moreover, the large specific surface areas increased from 538 m2/g to 780 m2/g of the SiO2@C composites.Benefitting from high specific surface area and ordered pore structure, the adsorption value of SiO2@C-900 was as high as 378 mg/g for ethyl violet dye; the removal rate of ethyl violet dye was 99% at the optimal adsorption condition of temperature 55℃ and pH 7, and the removal rate was still above 97% after repeated 5 times, indicating that these composites had good stability. The adsorption isothermal was in line with the Langmuir adsorption isothermal model, and the adsorption kinetics was in line with the second-order kinetic model, namely, which was mainly chemical adsorption.
Nano-cellulose (NCC) was used as raw material to prepare oxidized nanocellulose (TONC) by TEMPO reagent, and then TONC reacted with fatty amines that had different chain lengths under the action of catalyst to obtain fatty amine modified nanocellulose, which were prepared from octadecylamine (OCA) and named as DOATONC, TEATONC, HEATONC and OCATONC prepared from dodecylamine (DOA), tetradecylamine (TEA), hexadecylamine (HEA), respectively. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and elemental analysis showed that the aliphatic chain was successfully grafted, and the crystal form. of the modified nanocellulose did not change, which was the original type I crystal form. The angular and dispersibility tests showed that the hydrophilicity of the surface of the modified nanocellulose decreased significantly with the increase of the aliphatic chain length associated with the increment of contact angle from 65.8° to 93.9°. The dispersion decreased first and then increased, which was reflected by that the dispersion rate was 25.17% first fell to 11.97% and then rose to 71.71%. The composite membrane was prepared by adding 1% modified nanocellulose to polylactic acid (PLA). The mechanical properties test results showed that the mechanical properties of the composite membrane were significantly improved with the increase of fat chain, among which tensile strength and elongation at break of PLA/OCATONC composite membrane reached 40.2 MPa and 6.39%, respectively.
Furfural was prepared from hemicelluloses and lignocellulosic biomass in the presence of the γ-valerolactone/water solvent system with low cost sulfate as catalyst. The yield of furfural could be obtained as high as 50.2%, accompanying with 95.5% of hemicellulose conversion. Furthermore, furfural also could be prepared from real lignocellulosic biomass corncob and bamboo meal in the above catalytic system with the yield of 39.5% and 29.7%, respectively. In this case, corncob and bamboo meal conversion could be 86.5% and 80.50%.
The method of ClO2 delignification was used to decolorize and control the structure of fast-growing poplar. Under the condition of ensuring the intact shape of poplar board, the effects of treatment time on the structure and chemical components of fast-growing poplar were explored, and then the decolorized poplar was modified by polymethylacrylic resin(PMMA) impregnation. It was found that the brightness was 83.2% and decolorization was uniform after being treated with ClO2 for 3 h, the shape of the poplar board remained intact, the porosity increased from 11.8% to 31.4%, which effectively improved the pore passage of poplar. After being impregnated with polymethylacrylic resin, the decolorized poplar had beautiful appearance and good dimensional stability, and its mass increase rate, density and strength increased from 32.1%, 0.40 g/cm3 and 32.8 MPa of log to 80.5%, 1.48 g/cm3 and 87.4 MPa, respectively, which were more than 2.5 times of those of log.
Six novel hydronopyl gemini quaternary ammonium salts containing rigid alkyl chain groups, namely dibenzyl-1, 4-bis(hydronopyl dimethyl ammonium bromide)(3a), dibenzyl-1, 4-bis(hydronopyl diethyl ammonium bromide)(3b), dibenzyl-1, 4-bis(hydronopyl di-n-propyl ammonium bromide)(3c), dibenzyl-1, 4-bis(hydronopyl dimethyl ammonium chloride)(3d), dibenzyl-1, 4-bis(hydronopyl diethyl ammonium chloride)(3e), and dibenzyl-1, 4-bis(hydronopyl di-n-propyl ammonium chloride)(3f) were synthesized from hydronopyl tertiary amine compounds and 1, 4-dibenzyl bromide(chloride), respectively. Their structures were confirmed by FT-IR, MS and NMR. The antifungal activities of the novel compounds against eight plant pathogens were evaluated by mycelium growth rate method. The results showed that six hydronopyl gemini quaternary ammonium salts containing rigid alkyl chain groups had obvious antifungal activities against 8 plant pathogenic fungi. Among them, the EC50 values of all the compounds against Fusicoccum aesculi were lower than 10 mg/L, and the EC50 values against Coriolus versicolor and Fusarium oxysporum were lower than that of chlorothalonil. The antifungal activities of compounds 3a, 3b and 3c against Rhizocyonia solani, Colletotrichum gloeosporioides, Sphaeropsis sapinea and Fusicoccum aesculi showed a rise as the molecular weight of linkers.Compound 3f had good antifungal activity against Colletotrichum gloeosporioides, and the EC50 value was 3.447 8 mg/L.
In order to explore the preservation effect of rosin-based antistaling agent on postharvest citrus fruits, maleic rosin pentaerythritol ester(MRPE) was used as main component to prepare preservative, which was coated on ponkan for preservation and compared with uncoated ponkan and ponkan coated by morpholine fatty acid salt(MFAS) at room temperature storage conditions.Relevant indexes were measured every 6 days, and the results showed that after storing for 42 days, the weight loss rate of ponkan coated by MRPE coatings was 11.39%, which was 31.39% lower than that of the blank control group; firmness of ponkan coated by MRPE coatings was 1.61 N and the changes of firmness were lower than those coated by MFAS and the blank control; meanwhile, MRPE and MFAS coatings all could effectively inhibited the changes of soluble solids content and titratable acid content and the increase of malondialdehyde content(MDA). At the same time, the activities of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) of ponkan coated by MRPE were increased which were 9.90, 1.26 and 1.02 U/g after storing for 42 days. These results showed that the preservation effect of MRPE coating treatment was better than that of MFAS treatment, which indicated that rosin resin had a good application prospect in postharvest preservation of ponkan.
Desirable pine resources are the basis for the sustainable, high value-added and fine chemical utilization of pine oleoresin. According to the chemical composition and structural characteristics of pine oleoresin, combined with the analysis of the current situation of pine oleoresin resources as well as their deep processing and utilization industries, the demand for individuation pine resources is discussed from the perspective of fine utilization. By the perspectives of production, processing, utilization and benefits, intensive high-quality pine oleoresin resources are needed, which have strong oleoresin exudation, long-lasting resinosis, good quality, and easy processability. And by the perspective of deep processing and utilization, individuation oleoresin resources are needed further, which have higher quality, more useful, more balanced or more outstanding specific components. To research and breed individuation pine resources such as pimaric-type rosin, isopimaric-type rosin, mercusic-type rosin, α-pinene-type turpentine, β-pinene-type turpentine, 3-carene-type turpentine, β-phellandrene-type turpentine and longifolene-type heavy turpentine, are scientifically important and applicably valuable for the fine chemical utilization, high value-added deep processing of rosin and turpentine. It is recommended to focus on the main oleoresin-tapping pine species such as P. massoniana, P. kesiya var. langbianensis, P. elliottii, P. elliottii×P. caribaea, P. latteri Mason, etc., and carry out more integrative and interdisciplinary researches on oleoresin chemistry, fine chemicals, genomics, metabolomics, genetic breeding, resource cultivation, and chemical engineering of forest products.
The unreported nine camphene aldehyde O-substituted oximes (2a-2i) were synthesized by nucleophilic substitution reaction using 2-(3, 3-dimethyl bicyclic[2.2.1]hept-2-ylidene)acetaldehyde oxime and halide as raw materials. They were 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-benzyloxime (2a), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-butyloxime (2b), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(4-chlorobutyl)oxime (2c), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(3-bro minebenzyl) oxime (2d), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(4-tert-butyl benzyl) oxime (2e), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(4-chlorobenzyl) oxime (2f), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(4-cyanobenzyl) oxime (2g), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(2, 6-dichlorobenzyl) oxime (2h), 2-(3, 3-dimethyl bicyclic[2.2.1] hept-2-ylidene) acetaldehyde O-(ortho-fluorbenzyl) oxime (2i). These products were characterized by FT-IR, GC-MS, 1H NMR and 13C NMR. Taking 2a as an example, the effects of types of solvent, quantity of tetrabutylammonium bromide and benzyl chloride, reaction temperature and reaction time on reaction rate and yield of the product 2a were discussed. The optimum condition were obtained as follows:Methylbenzene as solvent, n(camphene aldoxime):n(benzyl chloride):n(tetrabutylammonium bromide)=1.0:1.8:0.08, the reaction temperature was 60℃, the reaction time was 20 h. Under these conditions, the yield of 2a was 84.1%. The inhibitory effects of compounds 2a-2i on HepG2 cells and MCF7 cells were studied by in vitro antitumor activity tests. The results showed that compound 2b had good inhibitory effect on HepG2 cells, and its IC50 value was 36.3 μmol/L. Compounds 2d, 2h and 2i had inhibitory effects on human MCF7 cells, especially compound 2h, with IC50 of 19.2 μmol/L.
The ethanol extract of the leaves of Castanopsis fleuryi was isolated by Sephadex LH-20, MCI gel CHP 20P, Toyopearl HW-40F, Chromatorex C18 column chromatography and simi-preparative HPLC purification techniques to obtain ten compounds. Their structures were elucidated by spectroscopic data and comparison with literatures as:gallic acid(1), ethyl gallate(2), dehydrodigallic acid(3), gentisic acid 5-O-β-D-glucoside(4), cretanin(5), apigenin(6), kaempferol-7-O-β-D-glucoside(7), astilbin(8), aromadendrin7-O-β-glucopyranoside(9), amarusine A(10). All compounds were isolated from this plant for the first time.
Supercapacitors are a new type of green energy storage device with the advantages of fast charging and discharging and long service life. The electrode material is the core component of supercapacitors. The carbon from biomass is considered as a good choice for the preparation of activated carbon because of its wide variety, low price, environmental friendly, porous structure and rich in hetero-atoms, and it is the most popular electrode material for commercial applications. This paper reviewd the effects of pore structure and specific surface area on the performance of electrochemical energy storage of activated carbon, summarized the common pore structures of biomass activated carbon such as tubular, lamellar, honeycomb and network and their electrochemical properties, and analyzed the effects of different biomass components on the performance of activated carbon from three categories: plant-based, animal-based and microbial-based. Finally, the traditional methods of preparing activated carbon and the new preparation methods in recent years were briefly introduced. The problems and challenges of biomass activated carbon were pointed out. Some suggestions were provided to guide the selection of precursors for biomass activated carbon.
(5R)-5-hydroxyltripthiocyanatolide(compound 5) was synthesized with triptonide as starting material through hydroxylation, reduction and nucleophilic substitution. On the basis of NMR and HRMS analysis, the structures were characterized and the results showed that compound 5 was successfully synthesized. The biological activities of compound 5 were tested and the results showed that compound 5 had inhibition rate of 69.95% against human lung cancer cell(A549 cells) at the concentration of 10 mg/L, which was equivalent to the level of the positive control (5R)-5-hydroxyltriptolide(LLDT-8), indicating that compound 5 had a certain antitumor activity; compound 5 was found to exhibit less inhibitory effect on leukomonocyte activation than the parent compound; more safety than LLDT-8 was observed on cytotoxicity assay on 293T cells. Target compound might mean an antitumor molecule for further development.
The degradtion of condensed tannin to tannin oligomers or monomers with low molecular weight is of great significance for improving their bioavailability and realizing high value-added utilization. This article comprehensively summarizes the research progress of condensed tannins in the fields of microbial degradation (fungal, bacterial), chemical degradation (acid degradation, alkaline degradation, precious metal catalytic degradation and biological enzymolysis), resin catalytic degradation, etc. The problems and solutions are summarized, and the future development direction is prospected.
Using rape straw, corn straw and camphor wood powder as raw materials, ZnCl2 was selected as a catalyst to carry out catalytic pyrolysis experiments in a horizontal tubular furnace reactor. The yields of the high value-added chemicals, e.g. furfural (FF), paraformaldehyde and 5-methylfurfural, in the bio-oil were taken as evaluation indexes. The results showed that the bio-oil yield of camphor wood powder was the highest, up to 51.76%, without catalyst. When ZnCl2 was the catalyst with a mass ratio of 1:1 in the pyrolysis, the bio-oil yield of the three raw materials decreased. And the bio-oil yield of camphor wood powder (30.50%) decreased significantly. The yield of aldehydes in the bio-oil obtained from corn straw and camphor wood powder increased to 0.48% and 0.84%, respectively. After catalytic pyrolysis of rape straw, corn straw and camphor wood powder, the yield of furans in the bio-oil increased by 253.72%, 85.05%, and 202.32%, respectively. The yield of FF in bio-oil increased by 470.41%, 313.87%, and 340.99%, respectively. The yield of 5-methylfurfural increased by 318.18%, 200.00%, and 213.04%, respectively. Meanwhile, the yield of paraformaldehyde in the bio-oil obtained from the catalytic pyrolysis of corn straw by ZnCl2 increased increased slightly.
Lignocellulosic resource, derived from agricultural and forestry residues in China, is an abundant, cheap and renewable feedstock from which can be bioconverted to bio-based chemicals such as fumaric acid. Production of bio-based chemicals from lignocellulose owes important social, environmental and economic benefits. Fumaric acid, an important platform chemical, has been widely used in the areas of materials, food, medicine, chemical engineering, etc. Rhizopus oryzae, is used as the main producer of fumaric acid and requires a little nutrients for growth.This review discussed production of fumaric acid from lignocellulose by Rhizopus oryzae, focusing on metabolic pathway of glucose and xylose, lignocellulosic feedstocks, fermentation strategies, co-production of multiple products. The emerging technologies and methods will improve large-scale production of fumaric acid from lignocellulose by Rhizopus oryzae.
The activated carbon derived biomass waste corncob was investigated for the adsorption of antibiotic ciprofloxacin(CIP) from aqueous solution.The Box-Behnken design(BBD) of response surface methodology was used to optimize the operating conditions, the optimum adsorption conditions were found to be adsorption time of 537 min, adsorbent dosage of 0.46 g/L and pH 4.92. The results showed that the equilibrium adsorption amount of ciprofloxacin increased with the increase of temperature, and the adsorption equilibrium data were found to fit the Redlich-Peterson model and Sips model well. The thermodynamic parameters revealed the adsorption process of CIP on activated carbon was a spontaneous, endothermic and increasing entropy process.The Elovich model could perfectly describe the adsorption process of ciprofloxacin on activated carbon.At 298 K, the maximum adsorption capacity of ciprofloxacin was 238.01 mg/g, indicating that the corncob-based activated carbon was a promising adsorbent for the removal of ciprofloxacin from aqueous solution.