In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense （R. Br.） Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction ...In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense （R. Br.） Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power＇s〉solid to liquid ratio＇s〉extraction time＇s〉 ethanol concentration＇s. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows： extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1：17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.展开更多
Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The...Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The third procedure was microwave resonant cavity dynamic extraction(MRCDE). The results obtained by the three microwave-assisted extraction procedures were compared with those obtained by using traditional Soxhlet extraction. The results indicate that the MAE not only took a shorter time, but also simplified the procedure, and made the extraction a higher yield. At the same time the results obtained by the three MAE procedures were also compared with each other.展开更多
Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved b...Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved by soaking the sample with 70% methanol（1∶15,v/v）for 30 min,and then microwave irradiation for 11 min at a power of 600 W.Coupling the extraction process with HPLC-fluorescence presented good recovery,satisfactory precision,and good linear relation.Compared with a method from the Chinese Pharmacopoeia,the proposed method enables higher extraction efficiency and more accurate analytical results.It can be of potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.展开更多
The use of a microwave-assisted extraction （MAE） method for the extraction ofphlorotannins from Saccharinajaponica Aresch （S.japonica） has been evaluated with particular emphasis on the influential parameters, inc...The use of a microwave-assisted extraction （MAE） method for the extraction ofphlorotannins from Saccharinajaponica Aresch （S.japonica） has been evaluated with particular emphasis on the influential parameters, including the ethanol concentration, solid/liquid ratio, extraction time, extraction temperature, and microwave power. The MAE procedure was optimized using single-factor design and orthogonal array design （OAD）. The content of total phlorotannins in S. japonica was determined using a Folin-Ciocalteu （FC） assay. A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant （mg PGE/g DW） was obtained using the optimized model, which included an ethanol concentration of 55%, solid/liquid ratio of 1：8, extraction time of 25 min, irradiation power of 400 W, and temperature of 60~C. Under similar conditions, the application of a conventional extraction method led to a lower phlorotarmin yield of 0.585 mg PGE/g WD. These results demonstrated that the MAE approach provided better results for the extraction ofphlorotarmins from S.japonica and was a promising technique for the extraction of phenolic compounds from S. japonica and other materials. In addition, screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells （HepG2） by inducing their apoptosis. The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining.展开更多
In this study, with Saccharomyces cerevisiae as the experimental material, microwave-assisted technology, phenol-sulfuric acid method and UV spectro- photometry were employed to investigate the extraction rate of poly...In this study, with Saccharomyces cerevisiae as the experimental material, microwave-assisted technology, phenol-sulfuric acid method and UV spectro- photometry were employed to investigate the extraction rate of polysaccharides. Solid-liquid ratio, microwave power and microwave processing time were adopted as single factors to optimize the extraction conditions. Subsequently, orthogonal experiment was performed to investigate the optimal extraction process of polysaccha- rides from S. cerevisiae. The optimal extraction conditions were： solid-liquid ratio 1 ： 20, microwave power 250 W, microwave processing time 3 min, under which the extraction rate of polysaccharides reached 4.98%. Compared with conventional hot water extraction method, microwave-assisted extraction technology exhibited shorter extraction time, higher efficiency, and could save more energy.展开更多
Platycodon grandiflorum polysaccharides(PGPs)are naturally occurring compounds derived from the flowers of platycodon grandiflorum.the microwave assisted extraction(MAE)of PGPs was studied.A three-level and three-fact...Platycodon grandiflorum polysaccharides(PGPs)are naturally occurring compounds derived from the flowers of platycodon grandiflorum.the microwave assisted extraction(MAE)of PGPs was studied.A three-level and three-factor Box-Behnken design was used to optimize MAE conditions,and the effects of operating conditions including microwave power(180-540 W),extraction time(20-60 s)and liquid to solid ratio(20-30 v/w)on the extraction yield of PGPs were studied through response surface methodology(RSM).The results showed that the highest yield of PGPs reached 8.35 g/(100 g)at 360 W microwave power,40 s extraction time and 25.2 v/w liquid to solid ratio.The extraction yield of PGPs was significantly affected by liquid to solid ratio(P<0.01),microwave power and extraction time(P<0.05).Compared with the conventional solvent extraction,MAE is more efficient and rapid due to the disruption of the flower tissue microstructure as a result of microwave acoustic cavitation as observed with the scanning electron microscopy(SEM).A macroporous resin,HPD400,was found to be effective for purifying the PGPs extract.展开更多
基金Supported by Open Funds for Innovation Platforms of Colleges and Universities in Hunan Province(15K066)National College Students'Innovative Entrepreneuria Training Program(201510553003)Research Study and Innovative Experiment Plan Project for College Students in Hunan Province(2015-499)~~
文摘In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense （R. Br.） Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power＇s〉solid to liquid ratio＇s〉extraction time＇s〉 ethanol concentration＇s. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows： extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1：17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.
基金the Science and Technology Developing Fellowship Program(No.2 0 0 30 5 5 1- 7) by Jilin Province
文摘Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The third procedure was microwave resonant cavity dynamic extraction(MRCDE). The results obtained by the three microwave-assisted extraction procedures were compared with those obtained by using traditional Soxhlet extraction. The results indicate that the MAE not only took a shorter time, but also simplified the procedure, and made the extraction a higher yield. At the same time the results obtained by the three MAE procedures were also compared with each other.
基金the National Natural Science foundationof China(No.20875060) for financial support
文摘Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved by soaking the sample with 70% methanol（1∶15,v/v）for 30 min,and then microwave irradiation for 11 min at a power of 600 W.Coupling the extraction process with HPLC-fluorescence presented good recovery,satisfactory precision,and good linear relation.Compared with a method from the Chinese Pharmacopoeia,the proposed method enables higher extraction efficiency and more accurate analytical results.It can be of potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.
基金Supported by the National Natural Science Foundation of China(No.51203028)Rural Science and Technology Correspondent and Technology Service System Construction Projects,Guangdong Province(No.2010A020507001-91)Science and Technology Project of Panyu District,Guangzhou City(No.2010-12-08)
文摘The use of a microwave-assisted extraction （MAE） method for the extraction ofphlorotannins from Saccharinajaponica Aresch （S.japonica） has been evaluated with particular emphasis on the influential parameters, including the ethanol concentration, solid/liquid ratio, extraction time, extraction temperature, and microwave power. The MAE procedure was optimized using single-factor design and orthogonal array design （OAD）. The content of total phlorotannins in S. japonica was determined using a Folin-Ciocalteu （FC） assay. A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant （mg PGE/g DW） was obtained using the optimized model, which included an ethanol concentration of 55%, solid/liquid ratio of 1：8, extraction time of 25 min, irradiation power of 400 W, and temperature of 60~C. Under similar conditions, the application of a conventional extraction method led to a lower phlorotarmin yield of 0.585 mg PGE/g WD. These results demonstrated that the MAE approach provided better results for the extraction ofphlorotarmins from S.japonica and was a promising technique for the extraction of phenolic compounds from S. japonica and other materials. In addition, screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells （HepG2） by inducing their apoptosis. The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining.
基金Supported by Science and Technology Project of Shandong Province(2011GS2114)Science and Technology Project of Heze City(2010S002)
文摘In this study, with Saccharomyces cerevisiae as the experimental material, microwave-assisted technology, phenol-sulfuric acid method and UV spectro- photometry were employed to investigate the extraction rate of polysaccharides. Solid-liquid ratio, microwave power and microwave processing time were adopted as single factors to optimize the extraction conditions. Subsequently, orthogonal experiment was performed to investigate the optimal extraction process of polysaccha- rides from S. cerevisiae. The optimal extraction conditions were： solid-liquid ratio 1 ： 20, microwave power 250 W, microwave processing time 3 min, under which the extraction rate of polysaccharides reached 4.98%. Compared with conventional hot water extraction method, microwave-assisted extraction technology exhibited shorter extraction time, higher efficiency, and could save more energy.
基金Thanks Shandong University of Technology(2004KJM09)and the Subject of Domestic Visiting Scholar for outstanding teachers to support this work。
文摘Platycodon grandiflorum polysaccharides(PGPs)are naturally occurring compounds derived from the flowers of platycodon grandiflorum.the microwave assisted extraction(MAE)of PGPs was studied.A three-level and three-factor Box-Behnken design was used to optimize MAE conditions,and the effects of operating conditions including microwave power(180-540 W),extraction time(20-60 s)and liquid to solid ratio(20-30 v/w)on the extraction yield of PGPs were studied through response surface methodology(RSM).The results showed that the highest yield of PGPs reached 8.35 g/(100 g)at 360 W microwave power,40 s extraction time and 25.2 v/w liquid to solid ratio.The extraction yield of PGPs was significantly affected by liquid to solid ratio(P<0.01),microwave power and extraction time(P<0.05).Compared with the conventional solvent extraction,MAE is more efficient and rapid due to the disruption of the flower tissue microstructure as a result of microwave acoustic cavitation as observed with the scanning electron microscopy(SEM).A macroporous resin,HPD400,was found to be effective for purifying the PGPs extract.
