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Research Progress in Insecticides Targeting Nicotinic Acetylcholine Receptors
GUO Linchao;YANG Honghao;LI Wenye;JU Xiulian;LIU Genyan;Nicotinic acetylcholine receptors are an important kind of neuroproteins in insects with multiple subtype structures, which are important targets for the development of efficient and safe insecticides.A variety of insecticides have been developed against these targets.In this paper, we summarize the research progress in insecticides targeting nicotinic acetylcholine receptors in terms of action mechanism and chemical structure.
Microwave-Assisted Extraction of Total Alkaloids from Stephania Tetrandra and Determination of Tetrandrine Content by HPLC
ZHAO Hua,LI Hui-peng,LIAO Ke-jian (School of Petroleum and Chemical Technology,Liaoning Shihua University,Fushun 113001,China)In this paper,the microwave-assisted extraction technique of total alkaloids from Stephania tetrandra was optimized by single factor experiment and orthogonal experiment,and a determination method of tetrandrine content in tota1 alkaloids by HPLC was established.The optimal extraction conditions were as follows: ethanol volume fraction was 55%,liquid-solid ratio was 13∶1(mL∶g),extraction time was 3.5 min,and microwave power was 480 W.The results of determining tetrandrine content in total alkaloids by HPLC showed that there was a good linear relationship between peak area and tetrandrine content in the range of 6.0~30.0 μg·mL-1 and its mean recovery and RSD were 99.98% and 1.66%,respectively.The HPLC method was simple,sensitive,accurate with good repetition,so it could be used in determination of tetrandrine content in Stephania tetrandra.
Analysis of Calorific Value and Cellulose Content of Crop Straw
LI Ya-li;LIU Juan;GAO Jin-hong;Several common crop straws,such as wheat straw,corn stalk and cotton straw,were treated by alkali,and analyzed by thermogravimetric analyzer(TGA).The calorific values of these crop straws were also measured,and their cellulose contents were determined by a nitric acid ethanol method.The results showed that,the calorific values of straw powder were in the order of cotton straw powder>wheat straw powder>corn stalk powder;the cellulose contents in wheat straw,corn stalk,and cotton straw were 37.91%,47.38%,and43.66%,respectively.Moreover,the cellulose contents in these straws increased after treated by 10% NaOH solution,and the increasing rates were in the order of wheat straw>corn stalk>cotton straw.This research provides a reference for the pretreatment and comprehensive utilization of crop straws.
Extraction and Content Determination of Mulberry Polysaccharide
MA Ming-lan;LIU Yang;CAI Li-na;ZHANG Lin;TAN Jun-jun;Mulberry polysaccharide was extracted by hot water extraction,crude polysaccharide was obtained by alcohol precipitation method,and protein was further removed by 5% trichloroacetic acid to prepare purified mulberry polysaccharide.Through an orthogonal experiment,the optimal conditions of extraction were as follows:solid-liquid ratio of 1∶6(mg∶mL),extraction time of 0.5h,ethanol concentration of 90%,and 5%trichloroacetic acid with liquid-solid ratio of 875∶1(mL∶g)to deprotein.For 20 times scale-up experiment,the extraction rate of purified polysaccharide could reach 2.63%.Mulberry polysaccharide content was determined by aphenol-sulfuric acid method.Using glucose solution as the reference substance solution,there was a good linear relationship(R=0.9997)between the absorbance at 490 nm and the concentration,the solution had good stability within 3h(RSD=1.02%),It had good repeatability(RSD=1.22%),and the average recovery rate was99.67%(RSD=0.93%).This method meets the requirements of linearity,precision and caauracy,and the method is simple,low-cost and with wide applications.
Research Progress of Palladium Catalysts Supported by Inorganic Materials
JIAO Jian-li,HUANG Long-jiang,TENG Da-wei (College of Chemical Engineering,Qingdao University of Science and Technology,Qingdao 266042,China)The palladium catalyst is a kind of important metal catalyst.Solid-supported palladium catalysts as novel ones have been investigated extensively in recent years.The characters and applications of palladium catalysts supported by inorganic materials containing silica gel,molecular sieves,active carbon and metal oxide have been reviewed in the paper.And the supported palladium catalysts has a promising prospect in asymmetric reaction.
Study on the Extraction Process of Total Flavonoids in Chrysanthemum Indicum L. by Ultrasonic Treatment and Its Antibiotic Activity
ZHU Qing-shu,ZHAO Wen-ying (College of Chemical Engineering,Qingdao University of Science and Technology,Qingdao 266042,China)Extraction process of total flavonoids in Chrysanthemum indicum L.by ultrasonic treatment was optimized.The contents of total flavonoids were used as indexes,and the influence of ultrasonic treatment on the antibiotic activity of total flavonoids was tested.The optimum extraction process for total flavonoids was obtained as follows:under ultrasonic power 200 W,the drug powder was treated for 15 min by 45% alcohol with 12 times of the amount to drug weight,and the average extraction rate of the total flavonoids was about 2.86%.The optimized process was stable and workable.
The Research Progress in Biological Activity of Mannopeptin
SONG Gang,GAN Xin(School of Biotechnology,Hubei University of Technology,Wuhan 430068,China)The structure and characteristics of mannopeptin were introduced.The extraction method and biological activity were stated.The research and development progress of mannopeptin were discussed also.
Research Progress in Meroterpenoids Derived from Marine Fungi
WU Xiaohui;CHEN Binbin;HUANG Ying;WANG Yuqin;CHEN Zhongqing;HUANG Xiaoyuan;TANG Lingzhi;HONG Xuan;Living in the unique marine environment of high salt, high pressure, low temperature, and low light, marine fungi often have the characteristics of unique structure, diverse metabolism, and remarkable activity, and can produce a series of secondary metabolites with diverse functions and novel structures, which are important sources of meroterpenoids.The in vivo complex secondary metabolic pathways of marine fungi lead to the diversity of the backbone structures of the produced meroterpenoids, which have rich biological activities such as antibacterial, anti-tumor, and enzyme activity inhibition.In this paper, we introduce the research status of meroterpenoids derived from marine fungi, and review its biosynthetic pathways, fermentation and isolation, and biological activities.The study provides a reference for the future research of meroterpenoids derived from marine fungi.
Study on Optimization of Microbial Fermentation of Ephedra Grass for Extraction of Ephedra Alkaloid
ZHANG Ying,SHEN Rui-min,XIA Yan,CHEN Ying,LIU Zhi-chang,WAN Duan-ji(School of Chemical & Environmental Engineering,Hubei University of Technology,Wuhan 430068,China)Ephedra grass was fermented by microbia for extraction of ephedra alkaloid and the fermentation conditions were explored.The optimized fermentation conditions were determined as follows:inoculation quantity of mycelium was 10%,ratio of solid to liquid was 1∶1.5,fermentation time was 20 h and fermentation temperature was 38℃.With the fermented ephedra grass,the extraction rate of ephedra alkaloid attained 0.9% at constant pressure under the optimum extraction conditions(including extraction time of 1 h,extration temperature of 80℃,ratio of solid to liquid of 1∶10 and extraction frequency of 3 times),which enhanced 25.8% than that of traditional extraction process at high temperature and high pressure.It indicated that microbial fermentation of ephedra grass could increase the extraction rate of ephedra alkaloid,decrease the energy consumption and reduce the production cost.
Metabolic Regulation of Fermentation Processes
CHEN Gang-xin,XIE Hong-guo,YANG Feng-Ke(Chemical Engineering College,Qingdao University of Science &Technology,Qingdao 266042,China)In the field of industrial fermentation,fermentation microbiologists search for a rare overproducing strain in nature, then further deregulate the microorganism so that it overproduces huge quantities of a commercially important product such as a metabolite or an enzyme. Deregulation is brought about by nutritional as well as classical and molecular genetic manipulations to bypass and/or remove negative regulatory mechanisms and to enhance positive regulatory mechanisms. These mechanisms include induction, nutritional regulation by sources of carbon, nitrogen and phosphorus, and feedback control. The controls and their modification are the subjects of this review.