Table of Content

30 March 2004, Volume 24 Issue 1 Previous Issue    Next Issue

研究报告

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SYNTHESIS OF β-O-4 TYPE LIGNIN MODEL COMPOUND AND ITS BIOMIMETIC DEGRADATION WITH GIF SYSTEM(Ⅱ) XIE Yi-min;HU Zhou-jian;WU Hong;LAI Yan-ming 2004, 24 (1):  1-6.  Abstract ( 721 )   PDF (1196KB) ( 1446 )   Save A lignin model compound of phenolic β-O-4 type,i.e.guaiacylglycerol-β-guaiacyl ether was synthesized with a modified method.Combination of infrared spectra analysis and 1H NMR was used to identify chemical structure of the products.Afterwards,the β-O-4 type model compound was treated with a new delignification system using (copper)/pyridine/peroxide(GIF system).High resolution 13C NMR and GC-MS analysis were used to investigate the change of chemical structure of β-O-4 type model compound during the reaction.Mechanism of this biomimetic delignification was also explored.Results showed that 4-(α-bromoacetyl)-guaiacol could be obtained from acetovanillone by bromination with copper(Ⅱ) bromide at high yield.Therefore,guaiacylglycerol-β-guaiacyl ether could be synthesized efficiently.Results also indicated that GIF type biomimetic system had strong ability on degradation of phenolic β-O-4 type model compound.After degradation,a series of low molecular aromatic compounds containing carboxyl,(hydroxyl) and carbonyl groups were produced.From their structures,the following reactions were caused by the GIF system:ether-bond cleavage,alkyl-aryl cleavage and Cβ—Cγ cleavage.Consequently,this work provides a comprehensive information on biomimetic delignification system that could be applied to industrial non-pollution bleaching. Related Articles | Metrics

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REACTION OF VEGETABLE TANNIN-ALDEHYDE-COLLAGEN ——A FURTHER UNDERSTANDING ON VEGETABLE TANNIN-ALDEHYDE COMBINATION TANNAGE LU Zhong-bing;LIAO Xue-pin;SUN Dan-hong;SHI Bi 2004, 24 (1):  7-11.  Abstract ( 886 )   PDF (495KB) ( 766 )   Save Using mimosa tannin as vegetable tanning agent and oxazolidine as aldehydic tanning agent,the effects of hydrogen bond,hydrophobic bond and side amino group of collagen on vegetable tanning,aldehyde tanning and vegetable-aldehyde combination tanning were investigated.Results indicated that aldehyde predominantly reacted with the side amino group of collagen even it was used after vegetable tanning.However,aldehyde could further react with vegetable tannin to form cross-linkage between collagen and vegetable tannin if highly nucleophilic sites in tannin molecules were available.As a result,the synergistic effect of the combination tanning in increasing hydrothermal stability of collagen fibers was achieved and the association between vegetable tannin and collagen was remarkably stabilized.This mechanism is appropriate for describing combination tanning with condensed tannins that contain nucleophilic sites.For hydrolysable tannins,however,no aldehydic cross-linkage between collagen and tannin could be observed.In (general),this research revealed the fact that the actual features of vegetable-aldehyde combination tanning should be different from the previously assumed one.With the mechanism suggested in this paper,all the phenomena in (vegetable) tannin-aldehyde-collagen interaction could be well understood. Related Articles | Metrics

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STUDIES ON SYNTHESIS AND OXIDATION OF NOPYL ACETATE WANG Zong-de;XIAO Zhuan-quan;CHEN Jin-zhu 2004, 24 (1):  12-16.  Abstract ( 734 )   PDF (601KB) ( 628 )   Save Nopol was synthesized from β-pinene,and nopyl acetate was synthesizd from nopol.Nopyl acetate was (oxidized) by acidic aqueous chromic anhydride,and 2 main products were identified by IR,MS,1H NMR and 13C NMR.They are 4-(1-methyl-1-hydroxy-ethyl)-1-cyclohexene-1-ethanolacetate and 4-(1-methyl-1-hydroxyethyl)-1-cyclohexene-1-ethanol.The former was obtained from cleavage of the four-membered ring followed by hydration,which was the main product of 50%-60% GC content of all the products.The latter was the hydrolyzate of the former.Several other products with comparatively high GC content,mainly 3 groups of isomers have been identified by GC-MS.They are (2,3-)epoxynopyl acetate,1-hydroxy-2,3-epoxynopyl acetate and 5-hydroxy-2,3-epoxynopyl acetate.Results suggested that the four-membered ring of nopyl acetate cleaved first,then hydrated.Other products were mainly obtained from epoxidation of the double bond,and further oxidation of tertiary hydrogen on C-1and C-5. Related Articles | Metrics

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STUDY ON VARIATION RELATIONSHIP BETWEEN CONTENT AND PROPERTIES OF PINANE HYDROGEN PEROXIDE AND FEASABILITY OF ITS APPLICATION LI Dong-mei;ZHAO Zhen-dong;LIU Xian-zhang;SUN Zhen 2004, 24 (1):  17-20.  Abstract ( 654 )   PDF (807KB) ( 830 )   Save Variation relationship between percentage concentration and properties of refined pinane hydrogen peroxide(PHP),such as refractive index,density and viscosity were studied.Effect of temperature on variation of PHP properties was studied as well.As results,there are perfect linear relationships between either refractive index(n) or density(ρ) and percentage content(c,%) of PHP,and the relationships meet regress functions:n=0.000 4c+1.461 2 and ρ=(0.002 5c)+0.850 7,respectively(c=0%-60%).However,there is no linear relationship between viscosity of PHP with its content.Temperature(t) affects remarkably refractive index and density of PHP over different concentrations with constant coefficient in their regress functions n=-4.01×10-4t+n0 and ρ=-7.25×10-4t+ρ0,respectively.These relationships could be applied to practical production of PHP,when proper improvement was brought.That is to say,there is the feasibility to determine on-line the content of PHP through the real-time analysis of its (refractive) index and (density.) Related Articles | Metrics

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EFFECT OF MICROWAVE TREATMENT ON PORE STRUCTURE OF ACTIVATED CARBON JIANG Wen-ju;JIANG Xia;ZHU Xiao-fan;JIN Yan 2004, 24 (1):  21-24.  Abstract ( 586 )   PDF (639KB) ( 925 )   Save Activated carbons were modified by microwave of 4 different powers at different time in high purity nitrogen ambient.Pore structure and microstructure of both conventional and modified activated carbons were tested by the (apparatus) of N2 adsorption and X-ray analysis.Effect of microwave treatment on pore structure of activated carbon was studied by comparing conventional and modified activated carbons.Results showed that microwave treatment of activated carbon resulted in insignificant change of surface area,decreased mesopore,basically unvaried micropore volume and enlarged microcrystallinity. Related Articles | Metrics

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ULTRASONIC-ASSISTED PROCESS(UAP) FOR SOLVENT EXTRACTION OF AZADIRACHTIN FROM NEEM SEED WANG Qiu-fen;SONG Zhan-qian;ZHAO Shu-ying~(;) 2004, 24 (1):  25-28.  Abstract ( 696 )   PDF (664KB) ( 938 )   Save The use of ultrasonic-assisted process(UAP) was investigated for solvent extraction of azadirachtin from neem seed under different operating conditions.Influences of ultrasonic power,solvent,ratio of material to liquid and ultrasonic treatment time on the yield of azadirachtin were studied.Optimal ultrasonic-assisted extraction conditions were:ratio of material to liquid 1:2(w/v) and ultrasonic power 200 W for 13.3 g seed powder.It was found that (extraction) yield of azadirachtin and ultrasonic time were different with different solvents(methanol as solvent,ultrasonic time 15 min,yield of azadirachtin 0.378 6%;ethanol as solvent,ultrasonic time 20 min,yield of azadirachtin (0.365 8%);ethyl acetate as solvent,ultrasonic time 10 min,yield of azadirachtin 0.246 2%).Content of azadirachtin in (extract was) estimated with HPLC technique.Results showed that UAP technique not only enhances the extraction yield of azadirachtin from neem seed but also has the advantage of high efficiency,compared to that of conventional solvent extraction method. Related Articles | Metrics

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PRODUCTION OF XYLITOL FROM HEMICELLULOSE HYDROLYSATE BY IMMOBILIZED CANDIDA TROPICALIS CELLS HUANG Wei;FANG Xiang-nian;XIA Li-ming 2004, 24 (1):  29-33.  Abstract ( 610 )   PDF (780KB) ( 837 )   Save Candida tropicalis cells were immobilized in Ca-alginate beads and used for xylitol production from corn cob hydrolysates.Optimum batch fermentation conditions were as follows:32℃;per liter nitrogen contains 2.2 g (bacto-yeast) extract and 3.7 g bacto-tryptone;initial pH value 6.0;volume ratio between gel beads of immobilized cells and hydrolysates 1:4;shaking speed was divided into two stages:210 r/min at 0-24 h,140 r/min at 24-72 h.In 10 repeated batches(30 days) fermentation,average xylitol yield was 73.7%.The immobilized cells have high density,steady fermentability and good resistance to inhibitors in the hydrolysates.Corn cob hydrolysates can be directly converted to xylitol without being decolored or ion-exchanged.This process can effectively reduce production costs,showing a broad prospects of applications. Related Articles | Metrics

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RESEARCH ON PREPARATION OF FIBER AND LIGNIN FROM BAMBOO WITH HIGH-BOILING ALCOHOL SOLVENT CHEN Wei-jian;CHENG Xian-su; 2004, 24 (1):  34-38.  Abstract ( 628 )   PDF (659KB) ( 772 )   Save In order to make fiber and lignin from bamboo,a high-boiling alcohol solvents(HBS) pulping procees with aqueous solvent of 1,4-butanediol was investigated.Bamboo chips were pulped with 70%-90% aqueous solution of 1,4-butanediol containing a small amount of catalyst at 180-200℃ for 30-90 min.HBS bamboo fiber is suitable for paper-making and producing cellulose derivatives by modification.Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation.HBS lignin has better chemical activity and lower ash content than (lignin) sulfonate.HBS lignin has potential applications in the fields of material science and engineering.High-boiling solvent could be recovered and recycled for pulping. Related Articles | Metrics

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STUDIES ON EXTRACTION OF RESVERATROL FROM POLYGONUM CUSPIDATUM BY MEDIUM-PRESSURE SILICA GEL COLUMN CHROMATOGRAPHY SU Wen-qiang;YANG Lei;ZHU Ming-hua;CHEN Qi-fan;LIU Wen-bin 2004, 24 (1):  39-42.  Abstract ( 755 )   PDF (545KB) ( 999 )   Save Extraction,separation,structure identification and content determination of resveratrol from Polygonum cuspidatum Sieb.et Zucc.had been carried out.Orthogonal experiment indicated that optimum extraction condition of resveratrol was:60℃,95% ethanol 1:11(raw material:ethanol),60 min and 3 times of extraction.Separation experiments with silica gel column under about 3 MPa pressure showed that ethyl acetate:petroleum ether was the ideal (eluant). After recrystallizing, resveratrol content was determined by HPLC to be as high as 99.28%.It can be (demonstrated) that this is a good technique used in resveratrol manufacture. Related Articles | Metrics

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STRUCTURE AND THERMAL BEHAVIOR OF NATURAL BAMBOO FIBERS FOR TEXTILE PURPOSES TANG Ren-cheng;YANG Xu-hong;WANG Hua-jie;MEI Shi-ying 2004, 24 (1):  43-47.  Abstract ( 753 )   PDF (677KB) ( 1462 )   Save The morphological,crystalline structure and thermal behavior of natural bamboo fibers for textile purposes were characterized by SEM,FT-IR,WAXD,TG and DSC analyses in comparison to cotton.Oblate pore space in the flat section of natural bamboo fibers and some aperture in their surface layer were observed,but no sheath-core structure was found in their section.Our analysis data showed that the procedure of extracting bamboo fibers from bamboo did not change the crystalline feature(celluloseⅠ) of bamboo fibers,but their degree of crystallization from WAXD and crystallinity index from FT-IR were higher than those of cotton.Thermal stability property and decomposition mechanism of natural bamboo fibers were the same as those of cotton,whereas they exhibited slightly lower heat-(absorption) and heat-release than cotton when decomposed under nitrogen and air respectively due to the stronger (hydrogen) bonding interaction between their molecular chains. Related Articles | Metrics

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CHARACTERISTICS OF LACCASE FROM WHITE-ROT FUNGUS PLEUROTUS OSTREATUS STRAIN 3.42 AND ITS DECOLORIZATION EFFECT ON ANTHRAQUINONE DYE HOU Hong-man;ZHOU Ji-ti;WANG Jing;DU Cui-hong;YAN Bin 2004, 24 (1):  48-52.  Abstract ( 752 )   PDF (732KB) ( 1048 )   Save White-rot fungus Pleurotus ostreatus strain 3.42 produces extracellular laccase,but no lignin peroxidase(LiP) and manganese peroxidase(MnP) are detected in the supernatant when grown in liquid culture.When [ 2, 2′-azino-bis(3-ethyl-benzthiazoline-6-sulfonic acid, ABTS)] (0.5 mmol/L) and Cu2+(0.1 mmol/L) were used as (inducer) of laccase production,high activity level up to 1 000 and 800 U/mL was obtained respectively.Compared with other fungus laccases,the laccase had an optimal pH value 3.5,and it was stable at pH value 4.0-6.0.Optimal (reaction) temperature of the laccase was 65℃,and it was very stable in sodium acetate buffer(pH value 5.0) at reaction temperature below 50℃.The laccase oxidized p-methoxyphenol faster than guaiacol.The laccase was strongly (inhibited) by sodium azide.In addition,anthraquinone dye Remazal Brilliant Blue R(RBBR) can be directly (decolourized) by the laccase(30 U/mL) at decolorization rate 70% after 12 h treatment.When ABTS(5 μmol /L) was used as a mediator of laccase,the dye could be completely decolourized. Related Articles | Metrics

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CHARACTERIZATION AND CATALYTICAL PROPERTIES OF AMINO-CARDANOL COPPER(Ⅱ) COMPLEX LIU Xiao-ying;LIN Jin-huo;XU Miao-qing;LI Guo-qing 2004, 24 (1):  53-55.  Abstract ( 507 )   PDF (682KB) ( 586 )   Save Amino-cardanol copper(Ⅱ) complex(AC-Cu2+),which is obtained by reacting amino-cardanal with CuCl2,is characterized by using IR,XPS,TG,etc.It is indicated that coordinate bond is formed between Cu2+ and functional groups —OH,—NH— in amino-cardanol.Resulted from the unsaturated coordination number of AC-Cu2+,the complex/Na2SO3/H2O system is reactive for catalytic-initiating the polymerization of monomers such as methyl methacrylate(MMA),butyl methacrylate(BMA) at room temperature. Related Articles | Metrics

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STUDY ON INFLUENCE OF METHANOL CONTENT ON PROPERTIES OF LOW-FORMALDEHYDE UF RESIN FU Shen-yuan;CHENG Ji;MA Ling-fei 2004, 24 (1):  56-60.  Abstract ( 791 )   PDF (733KB) ( 1007 )   Save Influence of methanol content in formaldehyde used as raw material for preparing low-formaldehyde(low molecular ratio) UF resin was studied.Results showed that high content of methanol in formaldehyde led to prolonged storage time of formaldehyde,increased storage stability of resin,higher free formaldehyde content in the resin and higher formaldehyde emission from plywood.Pot life and gelation time of the resin would be shortened by using NH4Cl as curing agents but pot life and curing time were still to long to adopt NH4Cl directly as suitable curing agent on the other hand,pot life and gelation time would be prolonged by using oxalic acid or 10% HCl as curing agents.Further tests on bond strength showed that higher content of methanol led to lower wet strength of plywood and lower wood (failure) ratio.When synthetic resin made with 1:1.1 mol ratio(U:F) and formaldehyde with methanol content higher than 6.0%,wet bond strength of poplar-core plywood could not reach 0.7 MPa level specified by GB/T 9846-1998,and wet bond strength of lauan-core plywood also decreased greatly,while dry bond strength was influenced insignificantly.Four hundred Hz 1H NMR spectra showed that high content of methanol would lead to higher content of (hydrated) formaldehyde in the resin and increased content of —OCH3 group.SEM results showed that cured resin graph was in tree shape for (resin) with lower methanol content in formaldehyde,while in loose shape for resin with (higher) methanol content in formaldehyde. Related Articles | Metrics

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DETERMINATION OF BETULIN CONTENT FROM BARK OF BETULA PLATYPHYLLA SUK.BY HPLC ZHANG Ze;SUN Hong 2004, 24 (1):  61-63.  Abstract ( 706 )   PDF (505KB) ( 934 )   Save An accurate HPLC method for the determination of betulin content from the bark of Betula platyphylla Suk.was described. The analytical column ODS C18 was used,with mobile phase methanol:water(88:12) using UV (210 nm),column temperature 30℃,column pressure 6.4 MPa,flow rate 1 mL/min.The linear range of betulin was (15.0-300.0 μg).Average recovery rate was 93.93%.Relative standard deviation of one sample repeated for 5 times was 3.26%.Compared with colorimetric method and GC method,HPLC method is more accurate and convenient. Related Articles | Metrics

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PREPARATION OF OIL-SORBING MATERIAL FROM INTERMEDIATE CUTTING WOOD OF CHINESE FIR BY THERMO-DEGRADATION HUANG Biao;GAO Shang-yu 2004, 24 (1):  69-72.  Abstract ( 580 )   PDF (638KB) ( 655 )   Save Oil-sorbing material was prepared from intermediate cutting wood of Chinese fir by processes comprised of wood cooking,mechanical fibrillating and thermo-degradation.Relations between oil-sorption properties of the product and temperature,extract content were studied.Water sorption of heat-treated fiber decreased when temperature increased.Oil-sorption(except at 350℃) showed much the same pattern,but the selectivity for oil was increased.Hot water and 1% NaOH extracts decreased with increasing temperature.Ethanol-benzene extracts decreased at 200-250℃ and then increased at 300℃.Significant decreases of ethanol-benzene extracts occurred at 400℃,which were caused by (secondary) decomposition and volatilization of these products.These results indicate that oil selectivity of the heat-(treated) wood fiber depends on the increased hydrophobicity of polysaccharides and decreased hydrophilic components.The adhesion of lipophilic pyrolyzate on the fiber surface greatly affects oil selectivity. Related Articles | Metrics

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DISSOLVATION RULES OF LIGNIN AND CARBOHYDRATES DURING RDH KRAFT PULPING OF EUCALYPTUS WOOD ZHAO Jian;LI Xue-zhi;SHI Shu-lan;HU Hui-ren 2004, 24 (1):  64-68.  Abstract ( 664 )   PDF (704KB) ( 536 )   Save Dissolving rules of lignin and carbohydrates(e.g.glucose,xylose,mannose,arabinose) during rapid displacement heating(RDH) kraft cooking for eucalyptus wood were investigated.Difference of cellulose crystallinity and α-cellulose content of pulps produced by conventional kraft cooking and RDH cooking were also studied.It was (observed) that delignification course during RDH pulping was divided into two phases:bulk phase and residual phase.As compared with conventional kraft pulping,the initial phase of delignification did not obviously occur during RDH pulping,and lignin was rapidly degradated and dissolved in the early period of RDH cooking.The dissolving rates of carbohydrates in the early period of RDH pulping were higher than that of conventional kraft pulping.Glucosidic component was rapidly dissolved in warm black liquor(WBL) stage and hot black liquor(HBL) stage of RDH cooking,but was slightly dissolved after HBL stage.Xylose 44.92%,mannose 33.46% and arabinose 49.09% have been dissolved in WBL and HBL stages of RDH process.After HBL stage,dissolving rates of xylose,arabinose and mannose decreased.As compared with conventional kraft pulps,RDH pulps have relatively high glucose(cellulose) content and relatively low xylose,arabinose and mannose(hemicellulose) content.The α-cellulose content of RDH pulp was a little higher than that of conventional kraft pulp.However,differences of cooking methods and cooking conditions have no significant effect on cellulose crystallinity. Related Articles | Metrics

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CHEMICAL CONSTITUENTS OF UNSATURATED FATTY ACID ETHYL ESTER FROM POPLAR BARK AND ITS MEDICINE EFFECTIVENESS ZHOU Wei-chun;JIANG Zi-rong;WANG Jin-qiu;SONG Qiang;SONG Jin-biao 2004, 24 (1):  73-76.  Abstract ( 622 )   PDF (722KB) ( 688 )   Save Unsaturated fatty acid ethyl ester product was obtained from poplar bark extract through saponification,(extraction),separation and purification,at yield 30%-36% of the extract.It consists of 95.94% esters of unsaturated fatty acid and 3.14% esters of saturated fatty acid.This product is analysed by GC.Of the 22 peaks,21 components which make up (99.19%) of the total weight were identified.The major component is linoleic acid whose content reached 94.04%.Medicine effectiveness test of the product showed that TC,TG and LDL-C in serum of high blood-(lipoid) rats(P<0.001) can be reduced obviously and content of HDL-C in serum is increased. Related Articles | Metrics

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STUDY ON PREPARATION OF TWO-COMPONENT ACRYLATE-POLY-UREATHANE WATER-BORNE WOOD COATING GRAFTED BY ORGANIC SILICON WEN Xiu-fang;WU Chang-rong;PI Pi-hui;CHENG Jiang;YANG Zhuo-ru 2004, 24 (1):  77-81.  Abstract ( 671 )   PDF (622KB) ( 926 )   Save Two-component acrylate-polyureathane water-borne wood coating grafted by organic silicon was prepared.Effects of kinds of organic silicone,acid value,hydroxyl content,neutralization degree,and glass transition temperature on the appearance,viscosity,water-solubility,consistency with curing agent,and film performance were studied.The optimal conditions were concluded as follows:hydrolytic hindering silicon is the suitable organic silicon monomer,acid value 35-50 mgKOH/g,hydroxy content about 3.5%,neutralization degree about 85%,and glass transition (temperature) 0-15℃. Related Articles | Metrics

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STUDY ON CHEMICAL CONSTITUENTS OF FRAGRANCE FROM FRESH FLOWERS OF EDGEWORTHIA CHRYSANTHA LI Zu-guang;LI Xin-hua;LIU Wen-Han;GAO Yun-fang 2004, 24 (1):  83-86.  Abstract ( 663 )   PDF (792KB) ( 1030 )   Save Fragrance constituents released from fresh flowers of Edgeworthia chrysantha Lindl.were investigated by gas chromatography-mass spectrometry.The volatiles were sampled by solid phase microextraction(SPME).SPME sampling was conducted with 30 μm PDMS fiber at (25±5)℃ for 30 min.The fibers were desorbed in a GC injection liner at 250℃ for 5 min.A capillary column(WCOT FUSED SILICA 30 m×0.25 mm ID COATING CP-SIL 8 (CB-LOW) BLEED/MS DF=0.25 μm) was employed in GC-MS analysis.Initial oven temperature was kept at 40℃ for 5 min,then raised to 250℃ at 3℃/min,and kept at 250℃ for 5 min.Chemical constituents were separated and identified by GC-MS.γ-Terpinene(56.41%),benzyl acetate(10.77%),2-phenyl ethyl acetate(9.58%),(3,7-dimethyl-2),6-octadien-1-ol,acetate(5.61%),methyl salicylate(3.91%),methyl benzoate(2.85%),trans-(ocimene)(1.80%),benzaldehyde(1.75%)and 3-decen-2-one,3-methyl(1.40%)were the most abundant volatiles released from fresh flowers of E. chrysantha,and a total of 30 volatile compounds were identified in this study.(SPME-GC-MS) afforded a feasible and simple method for analyzing volatiles released from fresh flowers. Related Articles | Metrics

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PRELIMINARY STUDY ON APPLICATION OF EXTRACT FROM BACCAE OF PERSEA AMERICANA L.IN COSMETIC INDUSTRY HUANG Cai-ping;HUANG An;CHEN Mei-gu 2004, 24 (1):  87-90.  Abstract ( 582 )   PDF (542KB) ( 770 )   Save Application of the extract from baccae of Persea americana L.in cosmetic industry has been studied.(Results) show that:1)Commingling the shampoo of ordinary formulation with avocado oil in the proportion of 1.0%-(1.2%),which is extracted from the baccae of P. americana L.,the stability,the restrainability of bacteria and mildew,the foamability and the antidandruffing ability of the shampoo will be enhanced;2)A proportion of 5% avocado oil in the skincream will increase the restrainability of comedos and dead skin,moisturizing and antisenescing ability of the cream;3)Avocado oil(1.0%-1.2%) in soap and showering gel has the functions of excellent antistimulation,moisturization and deodorization even at lower proportion than other surfurctants. Related Articles | Metrics

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RESEARCH ON PREPARATION OF ACTIVATED CARBON FROM BAMBOO KNOT WITH PHOSPHOROUS ACID BY MICROWAVE RADIATION PENG Jin-hui;FAN Xi-an;WANG Yao;QIN Wen-feng;GUO Sheng-hui 2004, 24 (1):  91-94.  Abstract ( 595 )   PDF (611KB) ( 676 )   Save Feasibility of preparing activated carbon from bamboo knot with phosphorous acid by microwave radiation was studied.Effects of microwave power,activation time and phosphorous acid solution concentration on the quality of activated carbon was investigated.Optimum technology and result were obtained as follows:microwave power 560 W,activation time 9 min and phosphorous acid solution concentration 40%(wt %),iodine value of activated carbon (889.0 mg/g),decolorizing capacity for methylene blue 178 mL/g and yield 31.0%.The activation time of this process was 1/45 times as fast as the conventional process.The decolorizing capacity for methylene blue was 1.48 times as much as that specied in National Standard(GB/T 12496.10-1999).A new way on utilizing bamboo knot resource was provided by this method. Related Articles | Metrics

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PRIMARY STUDIES ON BAMBOO-LEAF-FLAVONOIDS USED AS ANTI-AGING FACTOR FOR SKIN PROTECTION ZHANG Ying;SHEN Jian-fu;YU Zuo-yu;LU Bo-yi;LOU Ding-ding 2004, 24 (1):  95-100.  Abstract ( 848 )   PDF (869KB) ( 1368 )   Save The latest researches on the physiological activity of bamboo-leaf-flavonoids(EOB-f) on skin were described as follows:1)Security evaluation tests showed that EOB-f had no off-phenomenon such as pungency and allergy on rat’s skin and eye conjunctiva;2)Chemiluminescence and fluorescence analysis showed that EOB-f was of comparative activities with tea polyphenols and the extract of Ginkgo biloba on anti-free radicals,anti-oxidation,and anti-radiation;3)Bacteria inhibition test in vitro approved that EOB-f was capable of inhibiting various strains of infectious bacteria;4)Anti-inflammation tests revealed that EOB-f has obvious inhibiting effect on mice′s auricle swell caused both by croton oil and dimethylbenzene;5)Cell incubation tests in vitro displayed that,within the concentrations of (0.005%) to 0.05%,EOB-f accelerated significantly the proliferation of two kinds of rat skin cells,kerationcytes and fibroblasts,inhibited the pigment synthesis of B16 black pigment cancer cell,and depressed(MDA) content and enhanced SOD activity of rat skin kerationcytes.In conclusion,EOB-f possesses the essential and sufficient qualities applicable as a kind of safe,effective and economic plant components for anti-aging factor to protect skin in cosmetic. Related Articles | Metrics

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PROGRESS IN RESEARCHES OF BIOMIMETIC DELIGNIFICATION WANG Rui;QIAN Xue-ren 2004, 24 (1):  101-106.  Abstract ( 649 )   PDF (897KB) ( 1141 )   Save The research status and development trend of biomimetic delignification catalyzed by metal complexes were reviewed.Effects of porphyrins and nonporphyrins metal complexes used as biomimetic catalysts for delignification were evaluated.The application perspective of biomimetic delignification catalyzed by metal complexes was also prospected.Metalloporphyrins complexes had attracted much interest because of their high catalytic activity under (relatively) mild conditions.Chlorinated iron porphyrins were very stable because of the protective effect of chlorine (atoms) on porphyrins skeleton rings and showed high activity and reproducibility.The kinds of central metal ions of porphyrins also influenced the catalytic activity of delignification.Metalloporphyrins complexes are difficult to be used in practice because of their high cost.Nonporphyrins metal complexes such as metallophthalocyanines,Gif systems,Shiff-base complexes,etc.are being paid more attention due to their high catalytic activity,selectivity and easy synthesis. Related Articles | Metrics