[Objectives]To establish a TLC and content determination method of Pileostegia tomentellal,with umbelliferone as the indicator component.[Methods]TLC identification was performed by silica gel G thin layer plate with ...[Objectives]To establish a TLC and content determination method of Pileostegia tomentellal,with umbelliferone as the indicator component.[Methods]TLC identification was performed by silica gel G thin layer plate with n-hexane-ethyl acetate(4:3)as the developing agent,and the plate was examined by UV lamp(365 nm).The umbelliferone content was determined by HPLC:Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm);mobile phase acetonitrile-0.2%phosphoric acid gradient elution;detection wavelength 320 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The chromatogram of P.tomentellal showed the same color spot in the same position as that of reference medicinal material,and the spot was clear with good specificity.Umbelliferone showed a good linear relationship when the injection volume was 2.63-131.27μg/mL(R^(2)=0.9997).The average recovery of umbelliferone in the low,middle and high adding groups of P.tomentellal was 99.57%and the RSD was 2.15%.[Conclusions]The method can effectively identify Yao medicine P.tomentellal and accurately determine the content of umbelliferone in medicinal materials,which will provide a scientific basis for the development and utilization of medicinal resources of Yao medicine P.tomentellal.展开更多
[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experimen...[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh.展开更多
The pinewood nematode(PWN), Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid met...The pinewood nematode(PWN), Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid metabolic changes in ray parenchyma cells, create cavitation areas, decrease xylem water content and oleoresin exudation, and cause necrosis of parenchyma and cambial cells. This study focused on the impact of PWN infection on technological parameters of wood and evaluated the impact of anatomic and biochemical incidences of tree defense reactions on basic density, extractive content and moisture sorption properties of Pinus pinaster wood.Samples of infected and uninfected wood were studied.The presence of nematodes reduced wood basic density by2 % and decreased the total content of extractives in infected wood as compared with uninfected(5.98 and8.90 % of dry wood mass, respectively). Extractives in infected trees had inverse distribution along the trunk as compared with uninfected trees. The adsorption isotherms for infected and uninfected wood had similar positioning.We recorded differences(some statistically significant) in the equilibrium moisture content of infected and uninfected wood under varying environmental conditions. Despite the verified differences in wood basic density, extractive content and moisture sorption properties, the overall conclusion is that the PWN had a slight impact on these characteristics of wood.展开更多
Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna ...Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna zone in Nigeria. Tree mean specific gravity averaged 0.37; wood at the base had significant higher specific gravity than those at the top while it increased from pith to bark. For extractive content mean value was 1.20% for wood and 1.72% for bark; i[t varied significantly between trees and from base of the tree to the top and from pith to the bark. Extractive content at the butt and breast height is more than double of the value at the top of the tree. The high extractive content at the base is similar to high specific gravity observed for wood samples from the base. Extractive content of the bast was significantly higher than that of the wood. The low specific gravity show possible suitability of the species for paper making in Nigerian paper mills. The wood of Sterculia setigera showed a significant variation between- and within-trees in the two properties considered, though the wood is light with low extractive content; it is however a potential raw material for large scale pulpwood production in Nigeria.展开更多
Objective:To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol,flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al ...Objective:To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol,flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al Jabal Al Akhdar,Nizwa.Sultanate of Oman.Methods:The leave sample was extracted with methanol and evaporated.Then it was defatted with water and extracted with different polarities organic solvents with increasing polarities.The prepare hexane,chloroform,ethyl acetate,hutanol and methanol crude extracts were used for their evaluation of total phenol,flavonoids contents and phytochemical screening study.The established conventional metliods were used for quantitative determination of total phenol,flavonoids contents and phytochemical screening.Results:Phytochemical screening for various crude extracts were tested and shown positive result for flavonoids,saponins and steroids compounds.The result for total phenol content was the highest in hutanol and the lowest in methanol crude extract whereas the total flavonoids contents was the highest in methanol and the lowest hexane crude extract.Conclusions:The crude extracts from locally grown Thymus vulgaris showed high concentration of flavonoids and it could be used as antibiotics for different curable and uncurable diseases.展开更多
The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods (homogenized with distilled water at...The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods (homogenized with distilled water at room temperature, homogenized with 0.3% citric acid (w/v) at room temperature, 5- min boiling and homogenized with distilled water at room temperature, homogenized with 85℃ distilled water), and after preserving at room temperature, the change of the Epigallocatechin gallate (EGCG) contents of the extracts was investigated. Results indicated that the EGCG content of homogenate extracted with 85℃ distilled water was the highest before the extract was preserved, followed by that of the extract homogenized with 0.3% citric acid at room temperature. During preservation, EGCG content changed obviously. The EGCG contents of homogenates extracted with distilled water at room temperature and 85℃ distilled water declined quickly and separately reduced to 21.52% and 54.6% of their initial contents after preservation for 12 h. The EGCG contents extracted by 0.3% citric acid (w/v) solvent at room temperature and 5- min boiling/homogenized with distilled water at room temperature declined relatively slowly ,and separately reduced to 76.9% and 85.16% of their initial contents after preservation for 12 h. It was also found that the citric acid can prevent the degradation of EGCG and the extract solution color is light green展开更多
[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavono...[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavonoids in ginkgo leaves were studied,and the optimal extraction conditions for flavonoids were determined by orthogonal test; and with quercetin as reference substance,total flavonoid content in ginkgo leaves was determined by UV spectrophotometry.[Results]The optimal extraction process was 4 h of Soxhlet extraction with methanol; and the total flavonoid contents had a good linear relation in the range of 0. 006 5-0. 039 mg/ml( R^2= 0. 999 9),the average content was stabilized at 1. 135%,and the average recovery of the method was 102. 0%. [Conclusions]This study selected the optimal extraction process for total flavonoids in ginkgo leaves. The test method is simple with high accuracy and precision,and is suitable for the extraction and determination of total flavonoids in ginkgo leaves.展开更多
[Objectives] The moisture, ash and extract content of Dracocephalum tanguticum Maxim. were measured.[Methods] The moisture, total ash, acid-insoluble ash and extract content of D. tanguticum Maxim collected from 16 pr...[Objectives] The moisture, ash and extract content of Dracocephalum tanguticum Maxim. were measured.[Methods] The moisture, total ash, acid-insoluble ash and extract content of D. tanguticum Maxim collected from 16 producing areas were detected by using the methods in Chinese Pharmacopoeia (2015 edition, volume I), and D. tanguticum Maxim. was identified by thin layer chromatography in Chinese Pharmacopoeia (2015 edition, volume I).[Results] The moisture content of D. tanguticum Maxim collected from 16 producing areas ranged from 8.68% to 10.36%, averaging 9.28%. The content of total ash was between 7.21% and 11.60%, averaging 9.89%. The content of acid-insoluble ash was 0.21%-2.71%, averaging 1.51%. The extract content (water-soluble) was 26.67%-42.91%, averaging 32.65%. According to the results of TLC identification, the 16 samples and reference substance had the same characteristic spots at the corresponding positions.[Conclusions] It was recommended that the moisture, total ash and acid-insolue ash content of D. tanguticum Maxim were not be more than 11%, 12%, and 3% respectively, while the extract content was not less than 26%. It provides reference for filling the gaps in the quality standards of D. tanguticum Maxim.展开更多
When evaluating ionic liquids (ILs) for extractive desulfurization (EDS) of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few...When evaluating ionic liquids (ILs) for extractive desulfurization (EDS) of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few studies have considered this particular issue and a promoted water effect on EDS is scarcely reported. In this work, COSMO-RS was firstly employed to calculate the capacity and selectivity for EDS of various IL/H20 mixtures, which cover different IL characters and a wide water concentration range. Experiments were then conducted with a representative IL [C4MIM]IH2P04], whose stable and even promoted extraction performance with a small amount of water was suggested by COSMO-RS. Through analyses of the desulfurization ratio, the cross- solubility and the water content in the desulfurized fuel, the promoted effect of water within a certain range (〈 10 wt%) was experimentally demonstrated. Moreover, such effect of water was explained combining the viscosity, the solvent-solute interactions and the COSMO-RS based analysis.展开更多
[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials...[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials of L. alata in different production areas of Guangxi.[Methods]The content was determined by Inertsil~ODS-3 chromatographic column C_(18)( 4. 60 mm × 250 mm,5 μm,mobile phase: acetonitrile-0. 1% phosphoric acid( 22∶ 78),detection wavelength: 320 nm,flow rate: 1. 0 m L/min,column temperature: 30℃,and injection volume: 10 μL. [Results] The caffeic acid showed a good linear relationship in the range of injection volume of 0. 025 92-0. 259 2 μg( R =0. 999 5). The average recovery rate was 98. 33%( RSD = 1. 85%). L. alata in different production areas of Guangxi contained the caffeic acid,and there was a great difference in the caffeic acid. L. alata in Baise had the highest content of caffeic acid,while that in Guilin had the lowest content of caffeic acid. [Conclusions]This method can accurately determine the content of caffeic acid and is expected provide a scientific basis for the development and utilization of herbal medicine L. alata.展开更多
[Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pue...[Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pueraria lobata( Willd.) Ohwi. With the puerarin as index,the reflux extraction and single factor test were employed to investigate the effects of temperature,time,ethanol concentration and solid-liquid ratio on the content of total flavonoids in Pueraria lobata( Willd.) Ohwi,respectively. Under the optimal extraction technology,the content of total flavonoids in Pueraria lobata( Willd.) Ohwi at different altitudes was determined.[Results] The optimum extraction process was as follows: 70%ethanol; solid-liquid ratio of 1∶ 30; 1 h reflux extraction. Under these conditions,the extraction rate of flavonoids in Pueraria lobata( Willd.) Ohwi was 11. 48%,the total flavonoids content of different kudzu parts was in the order of roots > stems > leaves,and the total flavonoids content of the sample at about an altitude of 1000 m was significantly higher than at the altitudes of 1400 m and 1700 m.[Conclusions]It was suggested that the Pueraria lobata( Willd.) Ohwi should not be cultivated as medicinal plant in too high mountains,and the stems and leaves of Pueraria lobata( Willd.) Ohwi could be used as raw materials for extracting total flavonoids.展开更多
[Objectives] To optimize the extraction process of total flavonoids from Sanguisorbae Radix and carbonized Sanguisorba root,compare quality of different batches of Sanguisorbae Radix,study the effects of processing on...[Objectives] To optimize the extraction process of total flavonoids from Sanguisorbae Radix and carbonized Sanguisorba root,compare quality of different batches of Sanguisorbae Radix,study the effects of processing on the content of flavonoids,and provide scientific basis for reasonable utilization of Sanguisorbae Radix. [Methods] Test samples were prepared by heating,refluxing,and extraction,the extraction process was optimized by orthogonal experiment design,color was developed by NaNO_2-Al( NO_3)3-NaOH,and total flavonoids were measured by UV method at the wavelength of 510 nm. [Results] The linear relationship of rutin was excellent in the concentration range of 0. 1248 mg/mL-0. 5712 mg/mL,R^2= 0. 9997; the average recovery was 99. 67% and the RSD was 0. 70%. The optimum extraction conditions were as follows: the volume fraction of ethanol was 50%,the extraction temperature was 90℃,the extraction time was 90 min,and the solid-to-liquid ratio was 1∶ 20( g/mL). [Conclusions] After optimization of the extraction process,the extraction rate of total flavonoids in samples of Sanguisorbae Radix was significantly increased; there was certain difference in the content of total flavonoids between different batches of Sanguisorbae Radix and processed products; the total flavonoids significantly declines in carbonized sanguisorba root,and the influence of processing on its curative effect was to be further studied.展开更多
[Objectives]The research aimed to determine the contents of moisture,ash and extract of wild Paeonia veitchii Lynch produced in Sichuan,so as to provide the basis for evaluating quality of wild P.veitchii Lynch from S...[Objectives]The research aimed to determine the contents of moisture,ash and extract of wild Paeonia veitchii Lynch produced in Sichuan,so as to provide the basis for evaluating quality of wild P.veitchii Lynch from Sichuan.[Methods]Moisture,ash and extract contents of wild P.veitchii Lynch were respectively determined according to the fourth part of the Chinese Pharmacopoeia of 2015 version,and correlation analysis and TOPSIS analysis were used for data processing.[Results]12 batches of samples all corresponded with the provision that moisture of P.veitchii Lynch should not exceed 14.0%in the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version;11 batches of samples all corresponded with the provisions that total ash and acid insoluble ash of P.veitchii Lynch should not exceed 7.0%and 1.0%in the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version;average content of alcohol-soluble extract by hot dipping from 12 batches of samples was 42.29%,which was not less than 30.0%.In P.veitchii Lynch,moisture and acid insoluble ash showed positive correlation with altitude,while total ash and extract content were negatively correlated with altitude.Taking moisture,ash and extract as evaluation indexes,No.9 P.veitchii Lynch sample was the best.[Conclusions]Moisture and ash of P.veitchii Lynch corresponded with the provisions of the Chinese Pharmacopoeia of 2015 version and the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version,while extract content was higher than provision of the standard.The research could provide reference basis for rational utilization and quality evaluation of P.veitchii Lynch resources.展开更多
[Objectives]To establish a method for determining the content of caffeic acid in Zhuang Medicine Cryptolepis buchananii.[Methods]The content of caffeic acid in C.buchananii leaves was determined by high performance li...[Objectives]To establish a method for determining the content of caffeic acid in Zhuang Medicine Cryptolepis buchananii.[Methods]The content of caffeic acid in C.buchananii leaves was determined by high performance liquid chromatography(HPLC).[Results]The results of HPLC determination showed that the RSD values were less than 3%,and the content of caffeic acid in 10 batches of C.buchananii leaves was in the range of 0.0965%-0.4772%.[Conclusions]This method is accurate and reliable,has good linear relationship and high precision,and can be used for quality evaluation of C.buchananii.展开更多
[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L...[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L. franchetii from different localities were determined according to the methods described in Chinese Pharmacopoeia( 2015 Edition). [Results] In the 10 samples,the contents of moisture were all less than or equal to 15. 0%; the contents of total ash were all below 12. 0%; and the contents of acid-insoluble ash were all less than 3. 0%. The contents of water-soluble extract( by cold-soaked extraction method) in the samples were all below 12. 0% except those from Hongyuan Prairie of Sichuan Province and Xinglong Mountain in Lanzhou City,Gansu Province. [Conclusions]The contents of the four indicators measured in this experiment varied by small margins,indicating that the quality was relatively stable. This study provides theoretical data for the revision of the quality standards for L. franchetii.展开更多
Content extraction of HTML pages is the basis of the web page clustering and information retrieval,so it is necessary to eliminate cluttered information and very important to extract content of pages accurately.A nove...Content extraction of HTML pages is the basis of the web page clustering and information retrieval,so it is necessary to eliminate cluttered information and very important to extract content of pages accurately.A novel and accurate solution for extracting content of HTML pages was proposed.First of all,the HTML page is parsed into DOM object and the IDs of all leaf nodes are generated.Secondly,the score of each leaf node is calculated and the score is adjusted according to the relationship with neighbors.Finally,the information blocks are found according to the definition,and a universal classification algorithm is used to identify the content blocks.The experimental results show that the algorithm can extract content effectively and accurately,and the recall rate and precision are 96.5% and 93.8%,respectively.展开更多
[Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction ...[Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction rate of procyanidins as an indicator,the influence of pressure,temperature,and extraction time on extraction rate of procyanidins fromL. Ruthenicum Murr. was studied by single factor experimental methods and orthogonal array design. [Results]The order of factors affecting extraction rate of procyanidins was extraction temperature > extraction pressure > extraction time. The optimum extraction conditions were as follows: the extraction rate of procyanidins fromL. ruthenicum Murr. was the highest with extraction pressure of 1. 2 MPa,extraction temperature of 50℃ and extraction time of 90 min. The content of procyanidins in L. ruthenicum Murr. from different producing areas was determined by vanillin-HCl method under the optimal conditions. [Conclusions] The method has the advantages of easy operation,good selectivity,low extraction temperature and high extraction efficiency,which is suitable for extraction of procyanidins in L. ruthenicum Murr.展开更多
[Objectives]This paper aims to establish thin-layer identification and content determination method for Laggera alata(D.Don)Sch.Bip.ex Oliv.with chlorogenic acid as the index component and compare the content of chlor...[Objectives]This paper aims to establish thin-layer identification and content determination method for Laggera alata(D.Don)Sch.Bip.ex Oliv.with chlorogenic acid as the index component and compare the content of chlorogenic acid in L.alata from different places in Guangxi.[Methods]Silica gel GF254 thin-layer plate was used for identification under an ultraviolet lamp(365 nm),with butyl acetate-formic acid-water(V∶V∶V=7∶2.5∶2.5)as a developing agent.The content of chlorogenic acid was determined under the following chromatographic conditions:column,Inertsil ODS-3 C18 column(4.60 mm×250 mm,5μm);mobile phase,methanol-0.1%phosphoric acid(28∶72);detection wavelength,329 nm;flow rate,1.0 mL/min;column temperature,25℃;and injection volume,10μL.[Results]Chlorogenic acid can be detected by thin layer chromatography with clear spot and good specificity.Chlorogenic acid showed a good linear relationship in the injection amount range of 0.099-0.99μg(R^(2)=0.9999).The content of chlorogenic acid in L.alata varied greatly among the 10 different producing areas in Guangxi.L.alata produced in Dee Township,Longlin,Baise,Guangxi showed the highest chlorogenic acid content,and that produced in Shangsi County and Pingle County showed the lowest chlorogenic acid content.[Conclusions]This method can effectively identify L.alata and accurately determine the content of chlorogenic acid,thereby providing a scientific basis for the development and utilization of L.alata resources.展开更多
This paper had developed and tested optimized content extraction algorithm using NLP method, TFIDF method for word of weight, VSM for information search, cosine method for similar quality calculation from learning doc...This paper had developed and tested optimized content extraction algorithm using NLP method, TFIDF method for word of weight, VSM for information search, cosine method for similar quality calculation from learning document at the distance learning system database. This test covered following things: 1) to parse word structure at the distance learning system database documents and Cyrillic Mongolian language documents at the section, to form new documents by algorithm for identifying word stem;2) to test optimized content extraction from text material based on e-test results (key word, correct answer, base form with affix and new form formed by word stem without affix) at distance learning system, also to search key word by automatically selecting using word extraction algorithm;3) to test Boolean and probabilistic retrieval method through extended vector space retrieval method. This chapter covers: to process document content extraction retrieval algorithm, to propose recommendations query through word stem, not depending on word position based on Cyrillic Mongolian language documents distinction.展开更多
The main content of a news web page is a source of data for Natural Language Processing(NLP)and Information Retrieval(IR),which contains large quantities of valuable information.This paper proposes a method that formu...The main content of a news web page is a source of data for Natural Language Processing(NLP)and Information Retrieval(IR),which contains large quantities of valuable information.This paper proposes a method that formulates the main content extraction problem as a DOM tree node classification problem.In terms of feature extraction,we use the DOM tree node to represent HTML document and then develop multiple features by using the DOM tree node properties,such as text length,tag path,tag properties and so on.In consideration that the essence of the problem is the classification model,we use Xgboost to help select nodes.Experimental results show that the proposed approach is effective and efficient in extracting main content of new web pages,and achieves about 98%accuracy over 1083 news pages from 10 different new sites,and the average processing time per page is within 10 ms.展开更多
基金Supported by Self-funded Research Project of Administration of Traditional Chinese Medicine of Guangxi Zhuang Autonomous Region(GXZYA20220171)Young and Middle-aged Teachers Research Basic Ability Improvement Project of Colleges and Universities in Guangxi(2022KY0307)+5 种基金General Project of Guangxi University of Chinese Medicine(2022MS038)"Qingmiao Project"Talent Cultivation Program of Guangxi International Zhuang Medical Hospital(2022001)Key Project of Guangxi International Zhuang Medical Hospital(GZ2021010)High-level TCM Key Discipline(Zhuang Medical Science)Construction Project of State Administration of Traditional Chinese Medicine(zyyzdxk-2023165)Key Research and Development Project of Guangxi Provincial Department of Science and Technology(GK AB21196057)High-level Talent Cultivation Innovation Team Funding Project of Guangxi University of Chinese Medicine(2022A008).
文摘[Objectives]To establish a TLC and content determination method of Pileostegia tomentellal,with umbelliferone as the indicator component.[Methods]TLC identification was performed by silica gel G thin layer plate with n-hexane-ethyl acetate(4:3)as the developing agent,and the plate was examined by UV lamp(365 nm).The umbelliferone content was determined by HPLC:Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm);mobile phase acetonitrile-0.2%phosphoric acid gradient elution;detection wavelength 320 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The chromatogram of P.tomentellal showed the same color spot in the same position as that of reference medicinal material,and the spot was clear with good specificity.Umbelliferone showed a good linear relationship when the injection volume was 2.63-131.27μg/mL(R^(2)=0.9997).The average recovery of umbelliferone in the low,middle and high adding groups of P.tomentellal was 99.57%and the RSD was 2.15%.[Conclusions]The method can effectively identify Yao medicine P.tomentellal and accurately determine the content of umbelliferone in medicinal materials,which will provide a scientific basis for the development and utilization of medicinal resources of Yao medicine P.tomentellal.
基金Supported by Key Research and Development Program of Sichuan Province(2022YFS0436)Natural Science Foundation of Sichuan Province(2022NSFSC1738)+4 种基金Science and Technology Planning Project of Luzhou City(2021-JYJ-109,2023SYF120)Special Project of Traditional Chinese Medicine Scientific Research of Sichuan Provincial Administration of Traditional Chinese Medicine(2020CP0029)Southwest Medical University-Luzhou Hospital of Traditional Chinese Medicine Base Project(2019-LH003)Open Subject of Luzhou Key Laboratory of Fine Chemical Application Technology(HYJY-2106-B)Southwest Medical University Undergraduate Student Innovation and Entrepreneurship Training Program(202310632074).
文摘[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh.
基金supported by Grant No.SFRH/BPD/40135/2008 Funded by FCT(POPH-QREN-Typology 4.1,FCI and MEC)
文摘The pinewood nematode(PWN), Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid metabolic changes in ray parenchyma cells, create cavitation areas, decrease xylem water content and oleoresin exudation, and cause necrosis of parenchyma and cambial cells. This study focused on the impact of PWN infection on technological parameters of wood and evaluated the impact of anatomic and biochemical incidences of tree defense reactions on basic density, extractive content and moisture sorption properties of Pinus pinaster wood.Samples of infected and uninfected wood were studied.The presence of nematodes reduced wood basic density by2 % and decreased the total content of extractives in infected wood as compared with uninfected(5.98 and8.90 % of dry wood mass, respectively). Extractives in infected trees had inverse distribution along the trunk as compared with uninfected trees. The adsorption isotherms for infected and uninfected wood had similar positioning.We recorded differences(some statistically significant) in the equilibrium moisture content of infected and uninfected wood under varying environmental conditions. Despite the verified differences in wood basic density, extractive content and moisture sorption properties, the overall conclusion is that the PWN had a slight impact on these characteristics of wood.
文摘Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna zone in Nigeria. Tree mean specific gravity averaged 0.37; wood at the base had significant higher specific gravity than those at the top while it increased from pith to bark. For extractive content mean value was 1.20% for wood and 1.72% for bark; i[t varied significantly between trees and from base of the tree to the top and from pith to the bark. Extractive content at the butt and breast height is more than double of the value at the top of the tree. The high extractive content at the base is similar to high specific gravity observed for wood samples from the base. Extractive content of the bast was significantly higher than that of the wood. The low specific gravity show possible suitability of the species for paper making in Nigerian paper mills. The wood of Sterculia setigera showed a significant variation between- and within-trees in the two properties considered, though the wood is light with low extractive content; it is however a potential raw material for large scale pulpwood production in Nigeria.
基金Supported by Central Instrument Laboratory,College of Agriculture and Marine Sciences,Sultan Qaboos University,Sultanate of Oma(Grant No.507/SOP/OB/1/2013)
文摘Objective:To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol,flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al Jabal Al Akhdar,Nizwa.Sultanate of Oman.Methods:The leave sample was extracted with methanol and evaporated.Then it was defatted with water and extracted with different polarities organic solvents with increasing polarities.The prepare hexane,chloroform,ethyl acetate,hutanol and methanol crude extracts were used for their evaluation of total phenol,flavonoids contents and phytochemical screening study.The established conventional metliods were used for quantitative determination of total phenol,flavonoids contents and phytochemical screening.Results:Phytochemical screening for various crude extracts were tested and shown positive result for flavonoids,saponins and steroids compounds.The result for total phenol content was the highest in hutanol and the lowest in methanol crude extract whereas the total flavonoids contents was the highest in methanol and the lowest hexane crude extract.Conclusions:The crude extracts from locally grown Thymus vulgaris showed high concentration of flavonoids and it could be used as antibiotics for different curable and uncurable diseases.
文摘The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods (homogenized with distilled water at room temperature, homogenized with 0.3% citric acid (w/v) at room temperature, 5- min boiling and homogenized with distilled water at room temperature, homogenized with 85℃ distilled water), and after preserving at room temperature, the change of the Epigallocatechin gallate (EGCG) contents of the extracts was investigated. Results indicated that the EGCG content of homogenate extracted with 85℃ distilled water was the highest before the extract was preserved, followed by that of the extract homogenized with 0.3% citric acid at room temperature. During preservation, EGCG content changed obviously. The EGCG contents of homogenates extracted with distilled water at room temperature and 85℃ distilled water declined quickly and separately reduced to 21.52% and 54.6% of their initial contents after preservation for 12 h. The EGCG contents extracted by 0.3% citric acid (w/v) solvent at room temperature and 5- min boiling/homogenized with distilled water at room temperature declined relatively slowly ,and separately reduced to 76.9% and 85.16% of their initial contents after preservation for 12 h. It was also found that the citric acid can prevent the degradation of EGCG and the extract solution color is light green
基金Supported by Guilin Science and Technology Bureau Project(20100305)Guangxi"2011 Collaborative Innovation Center"-Zhuang Yao Medicine Collaborative Innovation Center Project(G2013[20])Special Fund for Traditional Medical Science and Technology of Department of Public Health of Guangxi Zhuang Autonomous Region(GZMZ1212)
文摘[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavonoids in ginkgo leaves were studied,and the optimal extraction conditions for flavonoids were determined by orthogonal test; and with quercetin as reference substance,total flavonoid content in ginkgo leaves was determined by UV spectrophotometry.[Results]The optimal extraction process was 4 h of Soxhlet extraction with methanol; and the total flavonoid contents had a good linear relation in the range of 0. 006 5-0. 039 mg/ml( R^2= 0. 999 9),the average content was stabilized at 1. 135%,and the average recovery of the method was 102. 0%. [Conclusions]This study selected the optimal extraction process for total flavonoids in ginkgo leaves. The test method is simple with high accuracy and precision,and is suitable for the extraction and determination of total flavonoids in ginkgo leaves.
基金Supported by National Key Research and Development Program of China(2018YFC1708005)Applied Basic Research Project of Sichuan Province,China(2018JY0066)Masters’ Key Project of Innovative Scientific Research Project for Postgraduates of Southwest Minzu University in 2018(CX2018SZ87)
文摘[Objectives] The moisture, ash and extract content of Dracocephalum tanguticum Maxim. were measured.[Methods] The moisture, total ash, acid-insoluble ash and extract content of D. tanguticum Maxim collected from 16 producing areas were detected by using the methods in Chinese Pharmacopoeia (2015 edition, volume I), and D. tanguticum Maxim. was identified by thin layer chromatography in Chinese Pharmacopoeia (2015 edition, volume I).[Results] The moisture content of D. tanguticum Maxim collected from 16 producing areas ranged from 8.68% to 10.36%, averaging 9.28%. The content of total ash was between 7.21% and 11.60%, averaging 9.89%. The content of acid-insoluble ash was 0.21%-2.71%, averaging 1.51%. The extract content (water-soluble) was 26.67%-42.91%, averaging 32.65%. According to the results of TLC identification, the 16 samples and reference substance had the same characteristic spots at the corresponding positions.[Conclusions] It was recommended that the moisture, total ash and acid-insolue ash content of D. tanguticum Maxim were not be more than 11%, 12%, and 3% respectively, while the extract content was not less than 26%. It provides reference for filling the gaps in the quality standards of D. tanguticum Maxim.
基金Supported by the National Natural Science Foundation of China(NSFC U1462123)PetroChina Innovation FoundationFundamental Research Funds for the Central Universities of China(22201313007)
文摘When evaluating ionic liquids (ILs) for extractive desulfurization (EDS) of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few studies have considered this particular issue and a promoted water effect on EDS is scarcely reported. In this work, COSMO-RS was firstly employed to calculate the capacity and selectivity for EDS of various IL/H20 mixtures, which cover different IL characters and a wide water concentration range. Experiments were then conducted with a representative IL [C4MIM]IH2P04], whose stable and even promoted extraction performance with a small amount of water was suggested by COSMO-RS. Through analyses of the desulfurization ratio, the cross- solubility and the water content in the desulfurized fuel, the promoted effect of water within a certain range (〈 10 wt%) was experimentally demonstrated. Moreover, such effect of water was explained combining the viscosity, the solvent-solute interactions and the COSMO-RS based analysis.
基金Supported by Project of National Natural Science Foundation(81660701&81260673)Project of Guangxi Graduate Education Innovation(YJS201625)+2 种基金Natural Science Foundation Project of Guangxi(2016GXNSFAA380148&2014GXNSFAA118208)Program of Key Laboratory for Purification and Quality Analysis of TCM Extraction in Guangxi Universities(Gui Jiao Ke Yan[2014]No.6)Laboratory of Chemistry and Quality Analysis in the Third Level Laboratory for Research of TCM(Zhuang)of State Administration of Traditional Chinese Medicine(Guo Zhong Yi Yao Fa[200]No.21)
文摘[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials of L. alata in different production areas of Guangxi.[Methods]The content was determined by Inertsil~ODS-3 chromatographic column C_(18)( 4. 60 mm × 250 mm,5 μm,mobile phase: acetonitrile-0. 1% phosphoric acid( 22∶ 78),detection wavelength: 320 nm,flow rate: 1. 0 m L/min,column temperature: 30℃,and injection volume: 10 μL. [Results] The caffeic acid showed a good linear relationship in the range of injection volume of 0. 025 92-0. 259 2 μg( R =0. 999 5). The average recovery rate was 98. 33%( RSD = 1. 85%). L. alata in different production areas of Guangxi contained the caffeic acid,and there was a great difference in the caffeic acid. L. alata in Baise had the highest content of caffeic acid,while that in Guilin had the lowest content of caffeic acid. [Conclusions]This method can accurately determine the content of caffeic acid and is expected provide a scientific basis for the development and utilization of herbal medicine L. alata.
基金Supported by Sichuan Science and Technology Support Program(2014SZ-0131)
文摘[Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pueraria lobata( Willd.) Ohwi. With the puerarin as index,the reflux extraction and single factor test were employed to investigate the effects of temperature,time,ethanol concentration and solid-liquid ratio on the content of total flavonoids in Pueraria lobata( Willd.) Ohwi,respectively. Under the optimal extraction technology,the content of total flavonoids in Pueraria lobata( Willd.) Ohwi at different altitudes was determined.[Results] The optimum extraction process was as follows: 70%ethanol; solid-liquid ratio of 1∶ 30; 1 h reflux extraction. Under these conditions,the extraction rate of flavonoids in Pueraria lobata( Willd.) Ohwi was 11. 48%,the total flavonoids content of different kudzu parts was in the order of roots > stems > leaves,and the total flavonoids content of the sample at about an altitude of 1000 m was significantly higher than at the altitudes of 1400 m and 1700 m.[Conclusions]It was suggested that the Pueraria lobata( Willd.) Ohwi should not be cultivated as medicinal plant in too high mountains,and the stems and leaves of Pueraria lobata( Willd.) Ohwi could be used as raw materials for extracting total flavonoids.
基金Supported by National Science and Technology Project of the Ministry of Science and Technology in the 13th Five-Year Plan Period(2015BAC05B02)Key Technology R&D Program of Sichuan Province,China(2015SZ0034)Innovating Research Program of Postgraduates of Southwest Minzu University in2016(CX2016SZ038)
文摘[Objectives] To optimize the extraction process of total flavonoids from Sanguisorbae Radix and carbonized Sanguisorba root,compare quality of different batches of Sanguisorbae Radix,study the effects of processing on the content of flavonoids,and provide scientific basis for reasonable utilization of Sanguisorbae Radix. [Methods] Test samples were prepared by heating,refluxing,and extraction,the extraction process was optimized by orthogonal experiment design,color was developed by NaNO_2-Al( NO_3)3-NaOH,and total flavonoids were measured by UV method at the wavelength of 510 nm. [Results] The linear relationship of rutin was excellent in the concentration range of 0. 1248 mg/mL-0. 5712 mg/mL,R^2= 0. 9997; the average recovery was 99. 67% and the RSD was 0. 70%. The optimum extraction conditions were as follows: the volume fraction of ethanol was 50%,the extraction temperature was 90℃,the extraction time was 90 min,and the solid-to-liquid ratio was 1∶ 20( g/mL). [Conclusions] After optimization of the extraction process,the extraction rate of total flavonoids in samples of Sanguisorbae Radix was significantly increased; there was certain difference in the content of total flavonoids between different batches of Sanguisorbae Radix and processed products; the total flavonoids significantly declines in carbonized sanguisorba root,and the influence of processing on its curative effect was to be further studied.
基金Supported by the National Key Research and Development Program of China(2018YFC1708005)Key Research and Development in Science and Technology Rural Areas of Sichuan Province(2019YFN0089)Innovating Research Program of Postgraduates of Southwest Minzu University in 2018(CX2018SZ84).
文摘[Objectives]The research aimed to determine the contents of moisture,ash and extract of wild Paeonia veitchii Lynch produced in Sichuan,so as to provide the basis for evaluating quality of wild P.veitchii Lynch from Sichuan.[Methods]Moisture,ash and extract contents of wild P.veitchii Lynch were respectively determined according to the fourth part of the Chinese Pharmacopoeia of 2015 version,and correlation analysis and TOPSIS analysis were used for data processing.[Results]12 batches of samples all corresponded with the provision that moisture of P.veitchii Lynch should not exceed 14.0%in the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version;11 batches of samples all corresponded with the provisions that total ash and acid insoluble ash of P.veitchii Lynch should not exceed 7.0%and 1.0%in the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version;average content of alcohol-soluble extract by hot dipping from 12 batches of samples was 42.29%,which was not less than 30.0%.In P.veitchii Lynch,moisture and acid insoluble ash showed positive correlation with altitude,while total ash and extract content were negatively correlated with altitude.Taking moisture,ash and extract as evaluation indexes,No.9 P.veitchii Lynch sample was the best.[Conclusions]Moisture and ash of P.veitchii Lynch corresponded with the provisions of the Chinese Pharmacopoeia of 2015 version and the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version,while extract content was higher than provision of the standard.The research could provide reference basis for rational utilization and quality evaluation of P.veitchii Lynch resources.
基金Supported by Project for Improving Basic Research Ability of Middle Aged and Young Teachers in Colleges and Universities of Guangxi(2019KY0324)Graduate Project of Guangxi University of Chinese Medicine(YCSY20190096)+2 种基金Program of Collaborative Innovation Center of Zhuang and Yao Medicine(zyx[2015]-01)Sub-project of Guangxi Key Laboratory of Traditional Chinese Medicine Pharmacology(J16072)Student’s Platform for Innovation and Entrepreneurship Training Program of Guangxi University of Chinese Medicine in Guangxi Zhuang Autonomous Region(201910600022).
文摘[Objectives]To establish a method for determining the content of caffeic acid in Zhuang Medicine Cryptolepis buchananii.[Methods]The content of caffeic acid in C.buchananii leaves was determined by high performance liquid chromatography(HPLC).[Results]The results of HPLC determination showed that the RSD values were less than 3%,and the content of caffeic acid in 10 batches of C.buchananii leaves was in the range of 0.0965%-0.4772%.[Conclusions]This method is accurate and reliable,has good linear relationship and high precision,and can be used for quality evaluation of C.buchananii.
基金Supported by National Key Technology Research and Development Program(2015BAC05B02)Fundamental Research Funds for the Central Universities(2018NZD10)
文摘[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L. franchetii from different localities were determined according to the methods described in Chinese Pharmacopoeia( 2015 Edition). [Results] In the 10 samples,the contents of moisture were all less than or equal to 15. 0%; the contents of total ash were all below 12. 0%; and the contents of acid-insoluble ash were all less than 3. 0%. The contents of water-soluble extract( by cold-soaked extraction method) in the samples were all below 12. 0% except those from Hongyuan Prairie of Sichuan Province and Xinglong Mountain in Lanzhou City,Gansu Province. [Conclusions]The contents of the four indicators measured in this experiment varied by small margins,indicating that the quality was relatively stable. This study provides theoretical data for the revision of the quality standards for L. franchetii.
基金Project(2012BAH18B05) supported by the Supporting Program of Ministry of Science and Technology of China
文摘Content extraction of HTML pages is the basis of the web page clustering and information retrieval,so it is necessary to eliminate cluttered information and very important to extract content of pages accurately.A novel and accurate solution for extracting content of HTML pages was proposed.First of all,the HTML page is parsed into DOM object and the IDs of all leaf nodes are generated.Secondly,the score of each leaf node is calculated and the score is adjusted according to the relationship with neighbors.Finally,the information blocks are found according to the definition,and a universal classification algorithm is used to identify the content blocks.The experimental results show that the algorithm can extract content effectively and accurately,and the recall rate and precision are 96.5% and 93.8%,respectively.
基金Supported by 2016 Instrument Functional Development Project of Lanzhou Regional Center of Resources and Environmental Science Instrument,CAS(2018gl11)
文摘[Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction rate of procyanidins as an indicator,the influence of pressure,temperature,and extraction time on extraction rate of procyanidins fromL. Ruthenicum Murr. was studied by single factor experimental methods and orthogonal array design. [Results]The order of factors affecting extraction rate of procyanidins was extraction temperature > extraction pressure > extraction time. The optimum extraction conditions were as follows: the extraction rate of procyanidins fromL. ruthenicum Murr. was the highest with extraction pressure of 1. 2 MPa,extraction temperature of 50℃ and extraction time of 90 min. The content of procyanidins in L. ruthenicum Murr. from different producing areas was determined by vanillin-HCl method under the optimal conditions. [Conclusions] The method has the advantages of easy operation,good selectivity,low extraction temperature and high extraction efficiency,which is suitable for extraction of procyanidins in L. ruthenicum Murr.
基金Basic Research Ability Enhancement Project for Young and Middle-aged Teachers in Colleges and Universities of Guangxi in 2019(No.2019KY0341)National Traditional Chinese Medicine Special Technology Inheritance Talent Training Project 2016+1 种基金Open Project of Guangxi Zhuang Yao Pharmaceutical Engineering Technology Research Center(No.KJT1900105)Youth Foundation of Guangxi University of Chinese Medicine(No.2019QN036).
文摘[Objectives]This paper aims to establish thin-layer identification and content determination method for Laggera alata(D.Don)Sch.Bip.ex Oliv.with chlorogenic acid as the index component and compare the content of chlorogenic acid in L.alata from different places in Guangxi.[Methods]Silica gel GF254 thin-layer plate was used for identification under an ultraviolet lamp(365 nm),with butyl acetate-formic acid-water(V∶V∶V=7∶2.5∶2.5)as a developing agent.The content of chlorogenic acid was determined under the following chromatographic conditions:column,Inertsil ODS-3 C18 column(4.60 mm×250 mm,5μm);mobile phase,methanol-0.1%phosphoric acid(28∶72);detection wavelength,329 nm;flow rate,1.0 mL/min;column temperature,25℃;and injection volume,10μL.[Results]Chlorogenic acid can be detected by thin layer chromatography with clear spot and good specificity.Chlorogenic acid showed a good linear relationship in the injection amount range of 0.099-0.99μg(R^(2)=0.9999).The content of chlorogenic acid in L.alata varied greatly among the 10 different producing areas in Guangxi.L.alata produced in Dee Township,Longlin,Baise,Guangxi showed the highest chlorogenic acid content,and that produced in Shangsi County and Pingle County showed the lowest chlorogenic acid content.[Conclusions]This method can effectively identify L.alata and accurately determine the content of chlorogenic acid,thereby providing a scientific basis for the development and utilization of L.alata resources.
文摘This paper had developed and tested optimized content extraction algorithm using NLP method, TFIDF method for word of weight, VSM for information search, cosine method for similar quality calculation from learning document at the distance learning system database. This test covered following things: 1) to parse word structure at the distance learning system database documents and Cyrillic Mongolian language documents at the section, to form new documents by algorithm for identifying word stem;2) to test optimized content extraction from text material based on e-test results (key word, correct answer, base form with affix and new form formed by word stem without affix) at distance learning system, also to search key word by automatically selecting using word extraction algorithm;3) to test Boolean and probabilistic retrieval method through extended vector space retrieval method. This chapter covers: to process document content extraction retrieval algorithm, to propose recommendations query through word stem, not depending on word position based on Cyrillic Mongolian language documents distinction.
基金supported by National Key R&D Program of China(Grant No.2018YFC0830300)Science and Technology Program of Fujian,China(Grant No.2018H0035)+1 种基金Science and Technology Program of Xiamen,China(3502Z20183011)Fund of XMU-ZhangShu FinTech Joint Lab
文摘The main content of a news web page is a source of data for Natural Language Processing(NLP)and Information Retrieval(IR),which contains large quantities of valuable information.This paper proposes a method that formulates the main content extraction problem as a DOM tree node classification problem.In terms of feature extraction,we use the DOM tree node to represent HTML document and then develop multiple features by using the DOM tree node properties,such as text length,tag path,tag properties and so on.In consideration that the essence of the problem is the classification model,we use Xgboost to help select nodes.Experimental results show that the proposed approach is effective and efficient in extracting main content of new web pages,and achieves about 98%accuracy over 1083 news pages from 10 different new sites,and the average processing time per page is within 10 ms.