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Research Progress in Reaction Mechanism of Evaluation Method for Antioxidant Activity in vitro
ZENG Wenjun;LV Caimeng;DING Jianbao;LI Yanping;MA Jianlong;YANG Rui;YANG Jin;Free radicals such as reactive oxygen species can cause various diseases, so it is particularly important to scavenge free radicals or inhibit the generation of free radicals, that is, to perform antioxidant research.In vitro antioxidant experiment is an important means to evaluate the antioxidant activity, which has guiding significance for the screening and development of antioxidants.In this paper, we classify various evaluation methods for antioxidant activity in vitro according to the reaction mechanism, and review the research progress in reaction mechanism of common evaluation methods(chemical analysis method and cellular antioxidant activity method).Moreover, we put forward the combination of multiple evaluation methods which can help to evaluate antioxidant activity more accurately.
Green Extraction Process and Antioxidant Activity of Total Flavonoids from Ginkgo biloba Leaves
FU Jiale;GENG Zhi;GUO Yamin;YANG Jingjin;We investigated the effects of deep eutectic solvents(DESs) type, liquid-solid ratio, extraction temperature, n(choline chloride)∶n(urea),water content of DESs, and extraction time on the extraction rate of total flavonoids from Ginkgo biloba leaves by single-factor experiments.Moreover, we further optimized the extraction process of total flavonoids from Ginkgo biloba leaves by response surface methodologies.Furthermore, we comprehensively evaluated the antioxidant activity of total flavonoids from Ginkgo biloba leaves by the determination of scavenging rates of DPPH free radicals, ABTS free radicals, hydroxyl free radicals, and superoxide anion free radicals, metal ion chelating ability, and total reduction ability.The results show that the optimal extraction process is as follows: the liquid-solid ratio of 30∶1(mL∶g),the extraction temperature of 57 ℃,the n(choline chloride)∶n(urea) of 1∶1.6,the water content of DESs of 40%,and the extraction time of 60 min.Under above conditions, the extraction rate of total flavonoids from Ginkgo biloba leaves can reach 1.062%,and its antioxidant activity is significantly better than that by traditional ethanol extraction.
Research Status of Hydrogen Production from Reforming of Fossil Energy and New Biomass Energy
LI Liangrong;LI Qiuping;AI Sheng;DENG Zhiwei;NI Zhichao;QIU Hao;XIONG Lei;The development and utilization of hydrogen energy has become an ideal way to promote the clean and efficient utilization of fossil energy and support the large-scale development of renewable biomass energy, which has been in line with China′s energy structure transformation and sustainable development strategy.Chemical reforming for hydrogen production is one of the common hydrogen production technologies.From the perspective of chemistry and energy, we mainly review the problems and improvement methods in the process of hydrogen production from reforming of fossil energy and biomass energy.Moreover, we highlight the research status of reforming technology and reforming catalyst, and put forward the future research directions of hydrogen production from fossil energy and biomass energy.
Optimization in Extraction Process of Total Flavonoids from Salvia miltiorrhiza and Its Antibacterial Activity
LONG Xu;WANG Leimeng;GONG Li;LEI Yating;GUO Hui;JIN Ruyi;We comparatively studied the extraction process of total flavonoids from Salvia miltiorrhiza by ultrasonic method and thermal reflux method through single-factor experiments, and confirmed that the ultrasonic method is superior to the thermal reflux method.Moreover, we optimized the ultrasonic extraction process of total flavonoids from Salvia miltiorrhiza by response surface methodologies.Furthermore, we investigated the inhibitory activity of total flavonoids from Salvia miltiorrhiza against Gram bacteria.The results show that the optimal ultrasonic extraction conditions can be determined as follows: the solid-liquid ratio of 1∶10(g∶mL),the extraction time of 22 min, the extraction temperature of 68 ℃,and the ethanol volume fraction of 86%.Under above conditions, the extraction rate of total flavonoids from Salvia miltiorrhiza can reach 4.140 mg·g-1.The inhibitory effect of total flavonoids from Salvia miltiorrhiza on Gram bacteria is as follows: Escherichia coli>Staphylococcus aureus>Pseudomonas aeruginosa.
Determination of Contents of Total Flavonoids and Total Polyphenols in Hippophae rhamnoides L. from Different Origins and Their Antioxidant Activity
LI Na;HU Yueyue;GE Liang;We determined the contents of total flavonoids and total polyphenols in Hippophae rhamnoides L.from six origins by Al(NO3)3-NaNO2-NaOH method and Folin-phenol method,respectively.Moreover,we evaluated the antioxidant activity of Hippophae rhamnoides L. extract by the determination of the scavenging rates of DPPH free radicals,ABTS free radicals,and ·O~-2.The results show that there are some differences in the contents of total flavonoids and total polyphenols in Hippophae rhamnoides L.from different origins.Among them,the contents of total flavonoids and total polyphenols in Hippophae rhamnoides L.from Inner Mongolia are the highest,reaching 38.84 mg·g-1 and 33.31 mg·g-1,respectively,while those from Gansu are the lowest,reaching 8.50 mg·g-1 and 12.36 mg·g-1,respectively.The Hippophae rhamnoides L.extracts from different origins have higher antioxidant activity,which have a certain scavenging effect on three kinds of free radicals,and there is a dose-effect relationship within a certain concentration range.
Research Progress in Lentinan
LIAN Xixi;SUN Jianing;SUN Lingli;LIU Jia;WANG Lianzhi;DUAN Zhengchao;Lentinan is a kind of purified polysaccharide with natural bioactive components extracted from Lentinus edodes.In this paper, we introduce the structures of β-1,3-D-main chain and β-1,6-D-glucose residue branched chain of lentinan.Moreover, we compare and analyze the extraction, separation and purification methods of lentinan, and review the pharmacological activities of lentinan, such as immune regulation, inhibition of tumor cell proliferation, and anti-oxidation.
Improvemeut of Technology for Styrene Suspension Polymerization
WANG Qiao1,ZHANG Yu-qi1,LIU Yong2(1.College of Chemistry and Chemical Engineering,Yan′an University,Yan′an 716000,China;2.Yan′an Institute of Vocational Technology,Yan′an 716000,China)The effects of main influential factors such as the amount of initiator,stirring speed,reaction temperature,the amount of dispersant,and the volume ratio of water to monomer on the suspension polymerization of styrene were studied.The experimental results showed that the optimum conditions were as follows:styrene 20 mL,the volume ratio of water to monomer 5∶1,dispersant(polyvinyl alcohol)0.073 g,initiator(benzoyl peroxide) 0.7 g,stirring speed 400 r·min-1,and reaction temperature 80~85℃.Under above conditions,the polystyrene with appropriate particle size,good transparency and high yield of 98.95% was obtained.
Applications of Enzyme in Environmental Protection
DONG Ke-li,MA Xiao-jian,LU Feng(The Center of Biochemical Engineering,Zhengzhou University,Zhengzhou 450002,China)The fundamental enzyme engineering technologies,including production of enzyme preparation,seperation and purification of enzyme,immobilization of enzyme,alteration and modification of enzyme,were introduced in this paper.The research and application status of enzyme in the field of environmental protection,such as purification of water,treatment of petroleum and of industrial waste oils,controlling of white pollution and environmental monitor,were summarized as well.
Research Progress on Pretreatment Technologies of Lignocellulose
ZHAO Lü1,LI Zhi-guang1,2,LI Hui-yong1,2,XIE Lei1, ZHOU Zhi1(1.College of Science,Hunan Agricultural University,Changsha 410128,China;2.Institute of Cheimstry & Chemical Engineering,Central South University,Changsha 410083,China)This paper reviews the components and structure of lignocellulose,states some promising pretreatment technologies in recent years,evaluates the main pretreatment technologies.
Research Progress of Chlorogenic Acid
DENG Liang, YUAN Hua, YU Zong-yuan(Hubei Research Institute of Chemistry, Wuhan 430074, China)The distribution ,biosynthesis,properties, pharmaceutical activity,the extraction and purifying technology and applied prospect of chlorogenic acid were reviewed in this paper, which tried to provide references for the research of chlorogenic acid, and the production of the medicines comprising chlorogenic acids as well.