Table of Content

30 June 2008, Volume 28 Issue 3 Previous Issue    Next Issue

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Studies on Seperation of Polyprenols from leaves of Ginkgo biloba L.by Molecular Short Distillation WANG Cheng-zhang;WANG Wan-ling;YE Jian-zhong;ZHENG Guang-yao;ZHOU Hao;CHENG Xi-zhuan 2008, 28 (3):  23-27.  Abstract ( 676 )   PDF (903KB) ( 1051 )   Save Non-saponifiable matter of polyprenols from Ginkgo biloba L. was obtained by saponification,extraction and solvent refrigeration, using 5% NaOH-EtOH as saponifier,ratio of paste of petroleum ether to saponifier 1:5(g:mL).Molecular short distillation was first used to purify non-saponifiable matter of polyprenols. For the I grade molecular distillation, the optimum operation parameters were: condensation temperature 2.5℃, circulating-water temperature 60℃, feed temperature 60℃,distillation temperature 160℃,feed flow rate 180mL/h,scraper rate 200r/min,operation pressure 0.5--0.5Pa. The results showed that content of polyprenols in solution was raised to 55.6%,recovery rate of polyprenols from G. biloba L.(GP) was 98.5%, content of polyprenols in distillate residue could be raised from 46.2% to 83.7% of non-saponifiable matter, and there was no solvent residue. Thus, this mehod would be an ideal separation method to prepare high-purity polyprenols industrially. Related Articles | Metrics

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Review and Prospects of Utilization of Tree Extractives in China CHEN Jia-hong 2008, 28 (3):  111-116.  Abstract ( 678 )   PDF (1234KB) ( 634 )   Save Tree extractives occupied the main part of plant extracts, and play an important role in the continuable and efficient utilization of forest resource. Because of their prominent chemical and biological activities, tree extractives are widely used in manufacture of chemicals, medicine, food and pesticide. Research and industrial utilization of tree extractives have achieved rapid developments in China. For better progress, being faced with new opportunities and challenges nowadays, the tree extractives industry must be paid attention by hard work in technology innovation, macro market guidance, resource protection and standardization of products. Related Articles | Metrics

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Catalytical Performance of Supported Nano-amorphous Alloy NiB/MCM-41 on Hydrogenation of Rosin LV Zhi-guo;SONG Zhan-qian;GUO Zhen-mei;CHEN Yan;YU Shi-tao 2008, 28 (3):  1-6.  Abstract ( 635 )   PDF (655KB) ( 729 )   Save Hydrogenation of rosin catalyzed by supported nano-amorphous alloy NiB/MCM-41 prepared by chemical reductive deposition method was investigated. The catalyst showed excellent catalytic activity for hydrogenation of rosin. Under the optimum conditions for hydrogenation of rosin i.e. load volume of Ni 180-190℃, reaction time 5 h, the contents of dehydroabietic acid(DEHAA) and abietic acid (AA) in the product were less than 2.5% and 0.5% respectively. The distribution of hydrogenation products remained basically stable during the repeated using of the catalyst. The amorphous alloy structure of NiB active sites, typical mesoporous structure and high BET area in the prepared catalyst had been proved by XRD,TEM,EOAX,ICP and N2 adsorption-desorption. Related Articles | Metrics

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Study on Chemical Constituents of Rabdosia rubescens(Hemsl.)Hara Herb LU Hai-ying;LIANG Jing-yu;CHEN Rong;YU Juan 2008, 28 (3):  7-12.  Abstract ( 844 )   PDF (772KB) ( 683 )   Save The chemical constituents of Rabdosia rubescens(Hemsl.) Hara herb were studied. Seven compounds were isolated and their structures were elucidated by various spectroscopic methods as bisrubescensin D(Ⅰ), (10Z,14Z)-9,16-dioxo-octadec-10,12,14-trienoic acid (Ⅱ), 2'-acctamido-3'-phenyl propyl 2-benzamido-3-phenyl propionate (Ⅲ), α-amyrin (Ⅳ), β-amyrin (Ⅴ), olean-12-en-2β,3β-diol-28-oic acid (augustic acid, Ⅵ), 2α-hydroursolic acid (Ⅶ). Compound Ⅰ is a novel asymmetric ent-kauranoid dimmer, compound Ⅱ is a new unsaturated fatty acid, compounds Ⅲ and Ⅵ were obtained from this genus of plants for the first time, and compound Ⅴ was obtained from this plant for the first time. Related Articles | Metrics

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Study on Kinetic Behaviors of the Biocatalysis of Laccase on Oxidation of Phenolic Compounds——Using Catechol and Epicatechin as Model Substrates LUO Yao-hong;ZUO Ying;SU Yu-qi;MA Hui-ling 2008, 28 (3):  13-17.  Abstract ( 635 )   PDF (928KB) ( 923 )   Save Trametes versicolor laccase was employed to measure enzymatic kinetics parameters for oxidation of model substrates, namely catechol and epicatechin. The results showed that the maximum absorption wavelengths of laccase-catalyzed oxidation end-products from catechol and epicatechin were 388 and 408nm, respectively; Optimum pH values were 5.5 and 5.75, respectively; Optimum reaction temperatures were both 55℃, and laccase-catalyzed oxidations for both substrates fitted the Michaelis-Menten equation. Under the reaction temperature of 25℃, Kmalues for catechol and epicatechin were 0.279, 0.145mol/L, respectively; Vmax values were 0.114, 0.139A/(U·min), respectively. This indicates that the catalytic activity of laccase on oxidation of epicatechin is much more higher than that of catechol. For the bio-transformation of mixture from the 2 substrates, enzyme dosage for catechol should be adopted which is 0.04U/mL for substrate concentration 0.5mol/L. Related Articles | Metrics

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Application of Molecular Imprinting Technology for Separation of Puerarin and Effect of Solvent on Recognition of Molecularly Imprinted Polymer CHEN Li-na;DU Shu-hu;MA Kun-fang;CAI Zheng 2008, 28 (3):  18-22.  Abstract ( 622 )   PDF (999KB) ( 577 )   Save A rational design approach was taken to the planning and synthesis of a molecularly imprinted polymer (MIP) capable of extracting puerarin from pueraria extract. The polymer was evaluated by static adsorption experiment. A molecular modeling approach was used to elucidate template-monomer interaction. Data from spectral analysis were used to prove the prediction made by molecular modeling. The MIPs have high selectivity to puerarin,the recovery rate of puerarin at 78.0%,and purity at 86.5% were attained. The successful preparation of molecular-imprinted polymers for solid-phase extraction for puerarin provides an innovative opportunity for the separation of traditional Chinese medicine. Related Articles | Metrics

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Study on Catalytic Pyrolysis of Fresh Biomass MIN Fan-fei;ZHANG Ming-xu;CHEN Qing-ru;CHEN Ming-qiang 2008, 28 (3):  28-34.  Abstract ( 600 )   PDF (1107KB) ( 753 )   Save Catalytic pyrolysis of fresh corn stalk(CS) and wheat straw(WS) have been carried out by TG/DTG/DTA technology in the atmosphere of N2 with K2CO3, Na2CO3, ZnCl2 and CaO as catalyst, respectively. Catalytic pyrolysis of fresh biomass and the influences of the kinds of catalyst and the catalyst weight/biomass weight ratios on pyrolysis of fresh biomass were analyzed. The results indicate that pyrolysis characteristic of fresh biomass is better than stored biomass. The addition of catalysts leads to redistributing of volatile of fresh biomass during pyrolysis in different temperature ranges, and the main pyrolysis of biomass was moved to lower temperature range, with increased yields of volatile. The addition of calcium oxide leads to the largest yields of volatile. The influences of K2CO3 and Na2CO3 on biomass pyrolysis characteristics are similar. Increasing of K2CO3 weight/biomass weight ratio results in increasing of yields of volatile, increasing of initial thermal decomposition temperature and increasing of main pyrolysis temperature range of biomass. It is suitable for hydrodysis of biomass at K2CO3 dose of 10%-15%. Related Articles | Metrics

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Study on Flame-retarding Formaldehyde-free Two-component Waterborne-polyurethane Wood Adhesive TANG Yong;ZHANG Xiang;YANG Bing;WANG De-yi 2008, 28 (3):  35-38.  Abstract ( 663 )   PDF (764KB) ( 679 )   Save Phosphited polyvinyl alcohol (P-PVA) was synthesized from diethyl phosphite and oxidated polyvinyl alcohol (O-PVA) which was obtained by oxidation of polyvinyl alcohol with KMnO4. The structure of P-PVA was confirmed by FT-IR and 1H NMR. Using P-PVA as the main component and polyaryl polymethylene isocyanate (PAPI) as curing agent, the flame-retarding properties of the prepared particle board were investigated to have a limiting oxygen index (LOI) of 27.9, when the loading of P-PU was 18%. Result of TGA showed that compared with normal polyurethane (PU) adhesive, P-PU adhesive can decrease the initial decomposition temperature which prolongs the stage of low-temperature dehydration-carbonization and increases the yield of residue char of wood particleboard at high temperature. Related Articles | Metrics

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Chemical Composition and Antimicrobial Activity of the Essential Oil of Iris pallida Lam DENG Guo-bin;ZHANG Xiao-long;WANG Yan-yun;LIN Yu;CHEN Xiao-lan 2008, 28 (3):  39-44.  Abstract ( 944 )   PDF (950KB) ( 780 )   Save Essential oils from the fresh rhizomes and the naturally aged rhizomes of Iris pallida Lam. were analyed by GC-MS, respctively, and the relative contents of constituents were determined by area normalization method. The antimicrobial activity of the essential oil was evaluated against 3 fungi and 12 bacteria including 7 clinical isolated strains. The results show that: twenty-six volatile components were identified and determined in the oil of the fresh rhizomes, accounting for 92.09%of the total area of the peak, and the main compounds of the oil were tetradecanoic acid (31.77%), hexanoic acid(15.33%), 3-methyl-butanoic acid(12.20%), pentanoic acid(9.29%), heptanoic acid(7.91%), 3-methyl pentanoic acid(7.25%),octanoic acid(2.44%),2',4'-dihydroxy-3'-methylacetophenone(1.04%). Forty-five volatile components were identified and determined in the oil of the naturally aged rhizomes, accounting for 85.63% of the total area of the peak, and the main compounds of the oil were tetradecanoic acid(28.02%), tetradecanoic acid, ethyl ester(10.42%), 9,12-octadecadienoic acid(7.67%), dodecanoic acid(6.41%), hexanoic acid(5.14%), hexadecanoic acid(4.44%), dodecanoic acid ethyl ester(4.09%), linoleic acid ethyl ester(3.87%), hexadecanoic acid ethyl ester(3.13%), ethyl oleate(2.85%), α-ionone, 6-methyl-(1.39%), and decanoic acid(1.31%); the oil of the fresh rhizomes presented a broad antimicrobial spectrum, and the minimal inhibitory concentration (MIC) value was 0.25g/Land the minimal bactericidal concentration (MBC) value was 0.35g/L; the oil of the naturally aged rhizomes presented a broad antimicrobial spectrum, and had better antimicrobial activity against gram-positive bacteria, MIC value was 0.05g/L and MBC value was0.08g/L. Related Articles | Metrics

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Allelopathy and Chemical Components of Extract from Green Peel of Juglans mandshurica Maxim. SUN Mo-long;SONG Zhan-qian;FANG Gui-zhen 2008, 28 (3):  45-49.  Abstract ( 711 )   PDF (557KB) ( 865 )   Save The extract from green peel of Juglans mandshurica Maxim. was extracted by common method for studying its allelopathy and analyzing the chemical components. Results showed that the alcohol extract and the ethyl acetate part of alcohol extract (separated with ethyl acetate from alcohol extract) exhibit allelopathy (inhibiting seed germination and seedling growth) on Brassica chinesis, Raphanus sativus and Medicago sativa. Their effects were extract-concentration dependent, increasing with the increase of extract concentration. The chemical components in the ethyl acetate part of alcohol extract from green peel of J. mandshurica were analyzed by GC-MS. Results showed that the main chemical components and their GC contents in the ethyl acetate part of alcohol extract were: 5-hydroxy-1,4-naphthalenedione(juglone) 31.20%, n-hexadecanoic acid 9.99%, 7-methoxy-1-tetralone 7.99%, 1,5-naphthalenediol 7.15%, 2,6-dimethoxy-phenol 4.36%, 4-butoxy benzaldehyde 3.23%, 5-(hydroxymethyl)-2-furancarboxaldehyde 2.96%,1,3-dihydroxyacetone dimmer 2.94%,glycerin 2.77%, 1(3H)-isobenzofuranone 2.57%. Twenty-four compounds in the ethyl acetate part of alcohol extract have been identified with total GC content of 94.55%. Related Articles | Metrics

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Study on Degradation of Glucose in Formic Acid Solution SUN Yong;LIN Lu;DENG Hai-Bo;PENG Hong;LI Jia-zhe 2008, 28 (3):  50-54.  Abstract ( 738 )   PDF (888KB) ( 871 )   Save The degradation of β-D-glucose in formic acid solution has been studied. The effects of temperature (55-75℃) and retention time (0-2h) have been investigated. It has been revealed that β-D-glucose is only marginally degraded in formic acid, but severely degraded in formic acid with hydrochloric acid. The degradation products of β-D-glucose at 75℃ for 4h have been analyzed by GC-MS. The main degradation products are 1,3-dihydroxyl-2-acetone and hydroxyl acetaldehyde in 88% formic acid, however 5-methoxyl furfural in formic acid with hydrochloric acid. The route of degradation is the protonation and cleavage of the hydroxyl group on the C-4 in formic acid, while on the C-2 in formic acid with hydrochloric acid, where the protonation of hydroxyl group results in the rearrangement of carbon cation before completing the dehydration reaction. Experimental observations supported these two degradation pathways. Related Articles | Metrics

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Content and Structure of Tannins in Different Parts of Bayberry(Myrica rubra(Lour.)Sieb.et Zucc.) LI Min;XIANG Ping;YANG Zhi-wei;XIANG Cheng;LIN Peng;LIN Yi-ming; 2008, 28 (3):  55-60.  Abstract ( 942 )   PDF (1119KB) ( 603 )   Save Contents of total phenolics and extractable condensed tannins in leaves, branches and bark of Myrica rubra (Lour.) Sieb. et Zucc. were determined. In addition, type of condensed tannins, degree of polymerization and distribution of polymer were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The results were showed as follows: total phenolics content was the highest in bark (43.56%), followed by leaves(34.69%), and then branches(18.53%); while extractable condensed tannins content was the highest in leaves(25.67%), followed by bark(17.93%), and then branches(8.01%). Epigallocatechin-3-O-gallate was invariably the basic unit occurring in the three condensed tannins. A-type and B-type linkages were the common types among the structural units of polymers. Meanwhile tannins in leaves and branches had the larger highest polymerization degree than bark. Related Articles | Metrics

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Characterization of Cellooligosaccharides Using NMR Spectroscopy and X-ray Photoelectron Spectra PENG Hong;LIN Lu;LIU Yu-huan 2008, 28 (3):  61-65.  Abstract ( 659 )   PDF (430KB) ( 572 )   Save 1H-1H COSY and 13C-1H HSQC spectra were used to assign cellotriose, cellotetraose and cellopentaose preparatively separated on Bio-Gel P-2 column (2.5cm×125cm). The results illustrate that the configuration ratios of α-form to β-form (α/β) at C1 of the reducing end decrease with the increase of degree of polymerization (DP) for cellooligosaccharides in aqueous solution. The configuration for cellotriose is mainly the α-form (α/β, 0.52), while for cellotetraose and cellopentaose are mainly the β-form (α/β, 0.34 and 0.25 respectively). X-ray photoelectron spectra (XPS) analysis shows that the binding energy of C 1s was mainly assigned to 284.8 and 286.1 eV corresponding to C 1s1 (C—O) and C 1s2 (O—C—O), respectively. The ratios of C 1s1/C 1s2 increase with the increase of DP for cellooligosaccharides. Related Articles | Metrics

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Research on Comparison of Separating Methods for Lignin in Populus alba L.under Ordinary Pressure Lü Jian-bo;CAO Qing;XUE Yong-qiang 2008, 28 (3):  66-70.  Abstract ( 791 )   PDF (740KB) ( 674 )   Save Under ordinary pressure, the methods of Kraft cooking, bisulfite cooking and organic solvents cooking were compared for the effects of separating lignin in Populus alba L.. The experiments were carried out by orthogonal design, the results indicated: the removing yield of lignin from the saw dust of P.alba was 55.8% for the Kraft cooking, 47.3% for the bisulfite cooking, and 83.3% for organic solvents cooking. It showed that organic solvents cooking process performed the best effect of separating lignin, and the residue yield of lignin was the lowest in the solid phase extracts, only 6.3%. Distilling the waste liquid, lignin could be obtained, the yield of which reached to 82.11% of the content of lignin in the raw material, and the recovery yield of lignin arrived 98.75%. Organic solvents could be recovered and recycled. Related Articles | Metrics

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Water Purification Effect of Moringa oleifera Lam.Seeds as Coagulant DUAN Qiong-fen;MA Li-yi;LI Zhen-gui;ZHANG Zhong-quan;WANG You-qiong;GAN Jin;ZHENG Hua;AN Xin-nan 2008, 28 (3):  71-74.  Abstract ( 645 )   PDF (667KB) ( 881 )   Save A comparative study of Moringa oleifera Lam. seeds and chemicals as coagulant demonstrated that M.oleifera seeds was effective in purifying water, the effect was similar to polyaluminium chloride. As a natural, safe coagulant, M.oleifera seeds was able to reduce turbidity of water to below the World Health Organization's guideline value of ≤5FTU for drinking water, so it can be used to substitute the chemical coagulants in water treatment. Both M.oleifera seeds and the oil cake can remove turbi-dities of water, there was no obvious difference in terms of their effect and thus both can be used for water purification. In concern of the cost and comprehensive use of the seeds, the oil cake was more economic and reasonable. When the turbidity of water was 150.6FTU, the optimal dosage of M.oleifera seeds for water purification was 0.2g seeds per 1L water. Related Articles | Metrics

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Study on Chemical Constituents of Fragrance Released from Fresh Flowers of Three Different Osmanthus franrans Lour.during Different Florescences LI Zu-guang;CAO Hui;ZHU Guo-hua;GAO Jian-rong;SHEN De-long 2008, 28 (3):  75-80.  Abstract ( 777 )   PDF (862KB) ( 846 )   Save The headspace constituents released from fresh flowers of three different Osmanthus fragrans Lour. during different florescences were investigated by means of headspace solid-phase microextraction (SPME) coupled to GC-MS. The main volatile fragrans from fresh flowers of three different O.fragrans during different florescences were also studied. In this study, 22 volatile compounds were identified in O. fragrans var. thunbergii, 18 volatile compounds were identified in O. fragrans var.latifolius, 8 volatile compounds were identified in O. fragrans var. aurantiacus. (E)-ocimene,4-hexenyl acetate, cis-linalool oxide, trans-linalool oxide, β-linalool, trans-geraniol, τ-decalactone were the same volatiles released from fresh flowers of three different O. fragrans, so their fragrans had some resemblance. However, the fragrans in O. fragrans var. thunbergii were fragran and sweet because the contents of α-ionone,β-ionone and τ-decalactone were higher than others. The fragrans in O. fragrans var.latifolius were simple and elegant because the content of ocimene was higher than others. The fragrans in O.fragrans var. aurantiacus were less fragran and sweet, because there are no α-ionone, β-ionone and ocimene in it. The results indicated that headspace SPME-GC-MS afforded a simple sampling method for identification of the main volatile fragrance from fresh flowers during different florescences. Related Articles | Metrics

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Investigation on the Variation Pattern of Pore Structure of Wheat Straw Fiber during Recycling Process WU Wei-wei;WAN Jin-quan;MA Yong-wen;WANG Yan 2008, 28 (3):  81-85.  Abstract ( 633 )   PDF (1146KB) ( 659 )   Save Variation pattern of pore structure of wheat straw fiber during recycling process with N2 adsorption-desorption method under low temperature was investigated with transmission electron microscopy during different recycling times. The results showed that the pore size distribution of wheat straw fiber was complicated with numerous micropores and middle-size pores except large pores. After the first recycle, the pore volumes of micropores was decreased 3.2×10-5cm3/g and the average pore volume of middle-size pore was reduced 1.67×10-5cm3/g. After the second recycle, the pore volumes of micropores and middle-size pores were decreased 9.2×10-5cm3/gand 2.77×10-5cm3/gseparately compared with the first recycle. After the third recycle, the average pore volumes of middled-size pore decreased 5.81×10-5cm3/g compared with the second recycle, but the micropores disappeared, while pore distribution was changed insignificently.The average pore size and the surface area of fiber had a trend of drop during the recycling process. It was also found that after recycling and remoistening, the lumen of fiber had irreversible collapse and distortion, and there was lots of pleats that changed the shape and size of pores. Related Articles | Metrics

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Study on Manufacture of Activated Carbon from Phyllostachys pubescens Twig Using Microwave Irradiation CHEN Cong-jin;LI Yue;HU Hua-yu 2008, 28 (3):  86-90.  Abstract ( 546 )   PDF (782KB) ( 713 )   Save Feasibility of preparing activated carbon from moso bamboo (Phyllostachys pubescens) twig with ZnCl2 and H3PO4 using microwave irradiation was studied.The effects of ZnCl2 and H3PO4 solution concentration, ratio by weight of the stem of P. pubescens twip to ZnCl2 and H3PO4 solution, dipping time and microwave irradiation time on the quality of activated carbon were investigated. Under the condition of microwave power 900W,the optimum technology on preparation of activated carbon with ZnCl2 using microwave irradiation was obtained as follows:ZnCl2 solution mass fraction 50%, the ratio of weight of the stem of P.pubescens twip to ZnCl2 solution 1:5, dipping time 24h, microwave irradiation time 25min. The activated carbon yield reached 46.3% and decolorizing capacity for methylene blue was 12.7mL/0.1g,which was 1.41 times of the first grade standard of GB/T 13803.2-1999. The optimum technology on preparation of activated carbon with H3PO4 using microwave irradiation was obtained as follows:H3PO4 solution mass fraction 40%, the ratio of weight of the stem of P. pubescens twip to H3PO4 solution 1:5, dipping time 24h, microwave irradiation time 20min. The activated carbon yield reached 50.5%and decolorizing capacity for methylene blue was11.0mL/0.1g, which was 1.22 times of the first grade standard of GB/T 13803.2-1999. Related Articles | Metrics

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Study on Synthesis of 2,3,4-Trimethoxybenzoic Acid XU Hao;HUANG Jia-ling;QIN Qing;WANG Guang-hui;TAO Lin 2008, 28 (3):  91-93.  Abstract ( 680 )   PDF (554KB) ( 725 )   Save Preparation method of 2,3,4-trimethoxybenzoic acid is introduced, which was synthesized from 2,3,4-trihydroxybenzoic acid by methylation,hydrolysis,acidification and purification. The results showed that the optimal methylating condition was as follows: dosage ratio of dimethyl sulfate to 2,3,4-trihydroxybenzoic acid 4:1,dosage of calalyst 5%of 2,3,4-trihydroxybenzoic acid. The structure of the refined product was confirmed by IR and 1H NMR.The purity was 99.54% by HPLC. Related Articles | Metrics

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Study on Triterpenoids from Microtropis triflor Merr.et Freem WANG Kui-wu 2008, 28 (3):  94-96.  Abstract ( 664 )   PDF (414KB) ( 704 )   Save Chemical constituents in Microtropis triflora Merr. et Freem. stem were studied. Six compounds were isolated and elucidated as β-amyrin (Ⅰ), oleanolic acid (Ⅱ), β-amyrin palmitate (Ⅲ), lupeol (Ⅳ), lupenone (Ⅴ), 20(30)-lupene-3β, 29-diol (Ⅵ) by analyses of 1H NMR, 13C NMR and MS.CompoundsⅠ-Ⅵ are all isolated from M. triflora for the first time. Related Articles | Metrics

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Experiment and Analysis on the Slagging Characteristics of Sawdust Briquette LIU Sheng-yong;LI Wen-ya;SU Chao-jie;DANG Yu-li;WANG Xi-yun;WU Yang 2008, 28 (3):  97-100.  Abstract ( 591 )   PDF (756KB) ( 536 )   Save According to GB/T 1572-2001 (the measuring method of fuel slagging characteristics), GB/T 476-2001 (ash and slag analytical method) and relevant judging rules, the slagging characteristics of sawdust briquette were analyzed. Results showed that sawdust briquette has the trends of slight slagging and slight contamination, which can be used as fuel for various stoves, to achieve safe, stable and economical combustion. This study has supplied theoretical basis for designing combustion equipment of biomass briquette. Related Articles | Metrics

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Content Determination of Imperatorin in Angelica dahurica(Fisch.)Bench.et Hook.Seeds from Different Habitats by HPLC JIANG Xue;WANG Ping;WANG Yang;YAN Xiu-Feng 2008, 28 (3):  101-103.  Abstract ( 767 )   PDF (551KB) ( 622 )   Save A method for content determination of imperatorin in Angelica dahurica(Fisch.) Bench.et Hook.by HPLC was established. The HPLC separation was performed on a hypersil ODS2 column(250mm×4.6mm, 5μm), at flow rate 1 mL/min, with mobile phase of methanol-water (65:35, volume ratio) and detected at wavelength 254nm. Using uniform design, the optimal conditions for imperatorin extraction were explored to be ultrasonically extracted by 78% ethanol at 20℃ for 22min. Imperatorin contents in A.dahurica seeds from different areas were determined. The highest imperatorin content was 1.722%, from Suiyang, then from Hulin and Hailin which were1.519%and 1.031%respectively, and the lowest was 0.698%, from Daxing'anling. Related Articles | Metrics

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Study on Changes of Chemical Composition of Chinese Fir Wood before and after Carbonization ZHOU Jian-bin;DENG Cong-jing;ZHANG Qi-sheng 2008, 28 (3):  105-107.  Abstract ( 697 )   PDF (504KB) ( 791 )   Save Research on the change of chemical composition of Chinese fir (Cunninghamia lanceolata) wood before and after carbonization was carried out. The contents of alcohol-benzene solubles, lignin, cellulose, holocellulose and1%NaOH extract of the wood after carbonization at 160,190,220℃ respectively were determined. Results showed: with the rise of carbonization temperature, contents of alcohol-benzene solubles and lignin showed a rising trend; cellulose content showed an overall downward trend. Holocellulose content also showed a downward trend, which is more significat than cellulose. One percent NaOH extract content slightly increased. the higher the temperature, the more serious was the damage of the nutritional substance in wood, the better was wood preservative property, but strength was declined. At lower carbonization temperature, the strength and properties of wood can be better maintained. It should be based on actual needs of the timber to choose temperature of carbonization. Related Articles | Metrics

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GC-MS Determination of Fatty Acids in Fructus rhodomyrti Seeds CHEN Tao;XIA Xue-kui;LU Hui-ning;YANG Bo-lun 2008, 28 (3):  108-110.  Abstract ( 541 )   PDF (593KB) ( 732 )   Save The extract was extracted from the seeds of Fructus rhodomyrti using ether assisted by supersonic wave. The extract was transesterified in KOH-CH3OH and analyzed by GC-MS method equipped with25m×0.22mmcapillary column. The fatty acids in F.rhodomyrti seeds were determined. The results showed that there were 14 fatty acids in which linoleic acid, saturated fatty acids and oleic acid are the chief components and their relative contents were84.99%, 14.55%and0.28%, respectively. Among saturated fatty acids are 4-methypentanoic acid, hexanoic acid, octanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, n-octadecanoic acid, eicosanoic acid and docosanoic acid. In addition, there was a little amount of conjugated linoleic acid (CLA). Related Articles | Metrics

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Applications of Ionic Liquids in Chemistry and Industry of Forest Products ZHU Sheng-dong;WU Yuan-xin;CHI Ru-an;SHEN Xi-zhou 2008, 28 (3):  117-121.  Abstract ( 646 )   PDF (863KB) ( 599 )   Save Ionic liquids are defined as organic salts that melt below about100℃. Application of ionic liquids in chemistry and industry of forest products has provided a new platform for "green" comprehensive utilization of forest resources and development of forest products. In this paper, applications of ionic liquids in chemistry and industry of forest products were reviewed. The existed problems and future prospects of application of ionic liquids in green comprehensive utilization of forest resources and development of forest products were discussed. Related Articles | Metrics

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Progress of Research on Degradation of β-Carotene LIU Wei-juan; 2008, 28 (3):  122-126.  Abstract ( 770 )   PDF (978KB) ( 853 )   Save The research progress is reviewed and summarized on the degradations of β-carotene, whith include thermally oxidative degradation, pyrolysis, chemically oxidative degradation, photo-oxidative degradation, bio-oxidative degradation, and enzymatically catalyzed oxidative degradation, etc. There are some kinds of low-boiling-point oxygen-containing compounds as main products such as aldehydes, ketones, alcohols, carboxylic acids and their esters generated during degradation or pyrolysis of β-carotene through different routes or reaction mechanisms. The degradation products from β-carotene are important and usable for manufacturing flavors and perfumes. Related Articles | Metrics