[Objective] The paper was to study the algicidal effect of water-soluble extracts of Chinese chive under different environmental conditions, so as to provide reference for further study and development of new algicida...[Objective] The paper was to study the algicidal effect of water-soluble extracts of Chinese chive under different environmental conditions, so as to provide reference for further study and development of new algicidal substances. [Method] The effects of water-soluble extracts of Chinese chive on the growth of Microcystis aeruginosa under different pH, light and aeration conditions were compared and studied. [Result] The growth inhibition rate of water-soluble extracts of Chinese chive on M. aeruginosa was greater than 90% under different pH conditions. With the growth of M. aeruginosa, the culture liquid with different initial pH was finally tended to 9-9.5. The growth inhibition rate of water-soluble extracts of Chinese chive on algae cell increased with the prolongation of culture time within the light intensity range of 1 000-4 000 lx. The inhibition effect of water-soluble extracts of Chinese chive on M. aeruginosa under low light intensity(1 000 lx)was better than that under high light intensity, the best light intensity for growth was not conducive to the exertion of allelopathic effect. Meanwhile, aeration condition was more conducive to the inhibition effect of water-soluble extracts of Chinese chive on the growth of M. aeruginosa. [Conclusion] pH, light and aeration conditions all affected the inhibition effect of water-soluble extracts of Chinese chive treated by high temperature on M. aeruginosa. Understanding the effect of these environmental factors on algicidal effect of allelochemicals could provide reference for further study and development of new algicidal substances.展开更多
Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. ...Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source(single extract pellets) and the mixture of these extracts with different proportions(blended extract pellets) in juvenile turbot(Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52(wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio(the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous(52% crude protein) and isocaloric(20 k J g^(-1) gross energy) diets were formulated by replacing 0(control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an important role in improving the palatability of non-fishmeal protein sources in aquafeed.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
Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water...Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water-soluble polysaccharide were investigated, which contained liquid-solid ratio, temperature, time and pH. The results showed that pH was the most important factor of polysaccharide extraction, followed by temperature. The optimized extraction technology conditions were obtained. The liquid-solid ratio was 1:40, temperature was 90?C, time was 2.0 h, and pH was 2. The highest extraction rate of crude polysaccharide was 8.30%.展开更多
[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 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
The polyphenol content,antioxidant and antimicrobial activities of the extracts obtained by classical, ultrasonic and Soxhlet extractions from dry aerial parts of two Artemisia species(Artemisia vulgaris and Artemisia...The polyphenol content,antioxidant and antimicrobial activities of the extracts obtained by classical, ultrasonic and Soxhlet extractions from dry aerial parts of two Artemisia species(Artemisia vulgaris and Artemisia campestris)were compared.Ultrasound positively affected the yield of extractive substance and the kinetics of extraction,but the extract obtained by the classical extraction showed the highest antioxidant activities and contained higher total contents of phenolic compounds and flavonoids than the extracts obtained by two other extraction techniques.Both flavonoid aglycones(apigenin,quercetin,quercetin 3,3′-dimethyl ether)and flavonoid glycosides(rutin,hyperoside and kaempferol 3-rhamnoside)were identified by thin layer chromatograph(TLC)analysis in the extracts from both species.A.campestris extracts were richer in quercetin than A.vulgaris and its antimicrobial activity was also better than A.vulgaris.Extracts obtained from both species were found to be more effective on the tested yeasts than bacteria.The kinetics of the total extractive substances,such as phenolic,flavonoids and quercetin extraction,was successfully described by the model of unsteady-state diffusion.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
[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
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
[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
Grape pomace is the main by-product of wine production that concentrates bioactive metabolites of polyphenolic nature with antibacterial activity. Since grape pomace composition varied depending on grape variety, clim...Grape pomace is the main by-product of wine production that concentrates bioactive metabolites of polyphenolic nature with antibacterial activity. Since grape pomace composition varied depending on grape variety, climate, vineyard location, and winemaking technology, it is important to study the composition and antibacterial activity of each variety separately. In this study, antibacterial activity against different food pathogens was evaluated and its relation with polyphenols content was determined. Grape pomace from Cabernet Sauvignon and Syrah varieties was extracted with methanol/HCl 1% (v/v), followed by sequential extractions with hexane, chloroform and ethyl acetate. Ethyl acetate fraction had the highest antibacterial activity determined through the microdilution method, reaching over 90% of inhibition at 500 μg·ml-1 with the exception of Salmonella Typhi (70% of inhibition). Staphylococcus aureus and Escherichia coli were the most susceptible strains, exceeding 50% of inhibition at 62.5 μg·ml-1. Ethyl acetate fraction contains the highest phenolic concentration in both Cabernet Sauvignon (132.2 mg of GAE g-1) and Syrah (102.6 mg of GAE g-1) pomace, as determined by the Folin-Ciocalteau method. Antibacterial activity present in grape pomace extracts is in direct relation to the polar phenolic content, in particular that from Cabernet Sauvignon.展开更多
基金Supported by National Natural Science Foundation of China(30671240,30871588,41006097)Scientific Special Research Project of Ministry of Water Resources for Public Industry(200801028,200701031)+1 种基金Open Fund from Key Laboratory of Environmental Materials and Environmental Engineering of Jiangsu Province(K090025)Project of Yangzhou Polytechnic College of Environment and Resource(2010YZY-1)~~
文摘[Objective] The paper was to study the algicidal effect of water-soluble extracts of Chinese chive under different environmental conditions, so as to provide reference for further study and development of new algicidal substances. [Method] The effects of water-soluble extracts of Chinese chive on the growth of Microcystis aeruginosa under different pH, light and aeration conditions were compared and studied. [Result] The growth inhibition rate of water-soluble extracts of Chinese chive on M. aeruginosa was greater than 90% under different pH conditions. With the growth of M. aeruginosa, the culture liquid with different initial pH was finally tended to 9-9.5. The growth inhibition rate of water-soluble extracts of Chinese chive on algae cell increased with the prolongation of culture time within the light intensity range of 1 000-4 000 lx. The inhibition effect of water-soluble extracts of Chinese chive on M. aeruginosa under low light intensity(1 000 lx)was better than that under high light intensity, the best light intensity for growth was not conducive to the exertion of allelopathic effect. Meanwhile, aeration condition was more conducive to the inhibition effect of water-soluble extracts of Chinese chive on the growth of M. aeruginosa. [Conclusion] pH, light and aeration conditions all affected the inhibition effect of water-soluble extracts of Chinese chive treated by high temperature on M. aeruginosa. Understanding the effect of these environmental factors on algicidal effect of allelochemicals could provide reference for further study and development of new algicidal substances.
基金supported by Special Fund for Agroscientific Research in the Public Interest (201303053)Provincial Natural Science Foundation of Shandong (JQ201206) to G.H
文摘Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source(single extract pellets) and the mixture of these extracts with different proportions(blended extract pellets) in juvenile turbot(Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52(wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio(the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous(52% crude protein) and isocaloric(20 k J g^(-1) gross energy) diets were formulated by replacing 0(control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an important role in improving the palatability of non-fishmeal protein sources in aquafeed.
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Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water-soluble polysaccharide were investigated, which contained liquid-solid ratio, temperature, time and pH. The results showed that pH was the most important factor of polysaccharide extraction, followed by temperature. The optimized extraction technology conditions were obtained. The liquid-solid ratio was 1:40, temperature was 90?C, time was 2.0 h, and pH was 2. The highest extraction rate of crude polysaccharide was 8.30%.
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.
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 the Ministry of Science and Environmental Protection,Republic of Serbia(172047)
文摘The polyphenol content,antioxidant and antimicrobial activities of the extracts obtained by classical, ultrasonic and Soxhlet extractions from dry aerial parts of two Artemisia species(Artemisia vulgaris and Artemisia campestris)were compared.Ultrasound positively affected the yield of extractive substance and the kinetics of extraction,but the extract obtained by the classical extraction showed the highest antioxidant activities and contained higher total contents of phenolic compounds and flavonoids than the extracts obtained by two other extraction techniques.Both flavonoid aglycones(apigenin,quercetin,quercetin 3,3′-dimethyl ether)and flavonoid glycosides(rutin,hyperoside and kaempferol 3-rhamnoside)were identified by thin layer chromatograph(TLC)analysis in the extracts from both species.A.campestris extracts were richer in quercetin than A.vulgaris and its antimicrobial activity was also better than A.vulgaris.Extracts obtained from both species were found to be more effective on the tested yeasts than bacteria.The kinetics of the total extractive substances,such as phenolic,flavonoids and quercetin extraction,was successfully described by the model of unsteady-state diffusion.
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 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 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.
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.
文摘Grape pomace is the main by-product of wine production that concentrates bioactive metabolites of polyphenolic nature with antibacterial activity. Since grape pomace composition varied depending on grape variety, climate, vineyard location, and winemaking technology, it is important to study the composition and antibacterial activity of each variety separately. In this study, antibacterial activity against different food pathogens was evaluated and its relation with polyphenols content was determined. Grape pomace from Cabernet Sauvignon and Syrah varieties was extracted with methanol/HCl 1% (v/v), followed by sequential extractions with hexane, chloroform and ethyl acetate. Ethyl acetate fraction had the highest antibacterial activity determined through the microdilution method, reaching over 90% of inhibition at 500 μg·ml-1 with the exception of Salmonella Typhi (70% of inhibition). Staphylococcus aureus and Escherichia coli were the most susceptible strains, exceeding 50% of inhibition at 62.5 μg·ml-1. Ethyl acetate fraction contains the highest phenolic concentration in both Cabernet Sauvignon (132.2 mg of GAE g-1) and Syrah (102.6 mg of GAE g-1) pomace, as determined by the Folin-Ciocalteau method. Antibacterial activity present in grape pomace extracts is in direct relation to the polar phenolic content, in particular that from Cabernet Sauvignon.