微波辅助法大规模提取藤茶中的二氢杨梅素

研究了二氢杨梅素的微波辅助提取法和重结晶纯化法,提取实验中考虑了微波照射时间、加热时间和料液比等因素对提取率的影响,确定的最佳提取工艺条件为:微波照射时间为20 min;加热时间为50 min;料液比为1∶10,在此条件下二氢杨梅素的提取率为25.11%;纯化实验以水为结晶溶剂进行多次重结晶,结果表明可有效的除去二氢杨梅素的杂质,二氢杨梅素的含量由53.75%到95.75%。     

酶法提取藤茶茎中二氢杨梅素工艺研究

采用酶法提取藤茶废弃物茎中的二氢杨梅素,考察温度、pH、酶添加量和料液质量体积比对二氢杨梅素提取率和纯度的影响。结果表明,最佳提取工艺条件为:温度45℃,pH为4.46,酶添加量2.0%,料液质量体积比1∶20(g/mL)。在此条件下,二氢杨梅素提取率30.65%,纯度23.4%。优于常规热提法,与醇提相比,提取率提高10%左右,纯度没有提高。     

梵净山野生藤茶中二氢杨梅素的提取及体外抗氧化研究

研究梵净山野生藤茶中二氢杨梅素的提取及体外抗氧化。采用超声波辅助法从梵净山野生藤茶中提取二氢杨梅素,以1,1-二苯基-2-苦基肼自由基(DPPH·)和羟自由基(·OH)二种不同自由基体系研究二氢杨梅素的活性清除能力。结果表明:在实验浓度范围内,二氢杨梅素清除DPPH·的能力高于芦丁,二氢杨梅素浓度达到50 mg/L时,其清除率大于Vc,达到72.58%,随着二氢杨梅素浓度的增加,其清除·OH的能力逐步提高,最高可达到55.05%。因此,梵净山野生藤茶中二氢杨梅素具有较强的抗氧化能力。     

酶法提取藤茶茎中二氢杨梅素工艺研究

采用酶法提取藤茶废弃物茎中的二氢杨梅素,考察温度、pH、酶添加量和料液质量体积比对二氢杨梅素提取率和纯度的影响。结果表明,最佳提取工艺条件为:温度45℃,pH为4.46,酶添加量2.0%,料液质量体积比1∶20(g/mL)。在此条件下,二氢杨梅素提取率30.65%,纯度23.4%。优于常规热提法,与醇提相比,提取率提高10%左右,纯度没有提高。     

藤茶中二氢杨梅素提取纯化的方法研究进展

藤茶在我国已有多年的食用历史,其主要功效是祛湿消肿、止血消炎等。藤茶中富含多种活性物质,如黄酮类化合物和酚类化合物。其中,二氢杨梅素为主要的功效成分,主要具有抗氧化、抑制肿瘤细胞生长、保护心脑血管等功效。本文主要综述了藤茶中二氢杨梅素的各种提取方法。     

藤茶中二氢杨梅素的药理作用研究进展

藤茶是我国民间饮用较广的一种保健茶,因其具有重要的生理保健功能而广受欢迎。藤茶中含有较多的黄酮类化合物,其中主要的活性成分是二氢杨梅素,且含量最高。据报道,二氢杨梅素具有抗氧化、消炎、止咳、降脂、保肝护肝等作用,在食品工业和制药工业应用非常广泛。本文介绍藤茶中二氢杨梅素近年来的药理作用的研究状况,为藤茶的开发利用提供理论依据。     

二氢杨梅素在食品工业中的应用研究进展

二氢杨梅素是藤茶中的主要生物活性物质,是一种天然黄酮类化合物,具有抗氧化、抗肿瘤、消炎镇痛、抑菌等多种生理功效.近年来,对二氢杨梅素的生理功效方面的研究逐渐深入,其在软饮料、乳制品、果蔬保鲜、功能定食品、绿色食品原料等多个方面均有广泛利用.本文针对国内外二氢杨梅素在食品工业中的应用进行综述,旨在为二氢杨梅素的进一步开发...     

藤茶中二氢杨梅素的微波萃取

以干藤茶叶为原料,在微波辐射条件下,以水为溶剂提取二氢杨梅素,考察了微波功率、微波辐射时间、料液比、浸提时间等因素对提取率的影响,通过单因素分析和正交试验设计确定了最佳提取工艺条件。确定的最佳提取工艺条件为:微波功率为高档,微波辐射时间为3min,料液比为1:20,水浴浸提时间为2h。在此条件下二氢杨梅素的提取率为29%。     

藤茶类产品中功效成分二氢杨梅素超高效液相色谱检测方法研究

本研究针对藤茶类保健食品建立了功效成分二氢杨梅素的超高效液相色谱-紫外检测方法.对提取条件进行了优化,确定了提取方式:以藤茶植物形式制作的保健食品采用65%乙醇加热回流提取、以藤茶粗提物配制的保健食品采用65%乙醇超声提取功效成分二氢杨梅素.对色谱条件进行了优化,确定了色谱条件:色谱柱为Acquity UPLCTM B...     

藤茶中二氢杨梅素的提取和应用研究进展

藤荼中含有较多的黄酮类化合物二氢杨梅素,由于具有抗氧化、消炎、止咳、降脂、保肝护肝等作用,在食品工业和制药工业应用非常广泛.对二氢杨梅素的提取方法和应用研究进展进行了综述.     

重组酵母发酵半纤维素水解液生产酒精的研究

玉米秸秆中的半纤维素主要由五碳糖组成,普通的酿酒酵母不能发酵五碳糖。今利用基因重组酵母Sacchromyces cerevisiae ZU-10发酵玉米秸秆半纤维素水解液生产酒精,针对半纤维素水解液中的主要发酵抑制物,研究了硫酸根离子、乙酸、糠醛对重组酵母生长的影响,发现S.cerevisiae ZU-10细胞对SO42·,乙酸和糠醛的耐受浓度分别为5g·L·1、0.25g·L·1和0.08g·L·1。对玉米秸秆半纤维素的水解工艺进行了比较研究,结果表明,玉米秸秆采用1%H2SO4(固液比1:10),在95℃水解12h,其中的半纤维素水解率达到93%,发酵抑制物相对较少。半纤维素水解液经石灰中和、真空浓缩及离子交换处理后,可用于酒精发酵。半纤维素水解液的糖浓度与浓缩倍数及发酵抑制物浓度成正相关,对于重组酵母S.cerevisiae ZU-10,半纤维素水解液的适宜糖浓度为80g·L·1。在此浓度下,接种量1.2g·L·1(细胞干重计)、30℃、厌氧发酵96h,酒精浓度为31.05g·L·1,水解液中的木糖利用率达到95.85%。该研究结果对于促进半纤维素资源的转化利用,加速秸秆酒精的产业化进程具有重要意义。     

Removal of Lead Ions from Ginseng Ethanol Extracts by Dynamic Adsorption in a Fixed-bed Column

The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb²⁺ content was determined by inductively coupled plasma mass spectrometry. When the flowrate increased from 0.12 to 0.34 ml•min^-1, the column exhibited a marked increase in percentage of lead removal from 54.9% to 92.3%. Further increase in the flowrate did not bring evident changes to the lead removal, whereas an increase in the temperature could reinforce adsorption further, suggesting that the adsorption process was controlled by external film diffusion below the flowrate of 0.34 ml•min^-1, and by the intraparticle pore diffusion of lead ions when the flowrate exceeded it. A low remaining lead amount in extracts such as 0.11 mg•kg^-1 (extracts powder) was achieved. The adsorbents also adsorbed effective constituents to some extent. But 88% of constituents adsorbed were taken off using a 70% ethanol aqueous solution.     

正交设计优化海燕总皂苷的微波提取工艺

探讨了微波功率、提取时间、溶剂浓度、料液比四种因素对微波辅助提取法提取海燕中总皂苷提取率的影响。并以正交设计实验优化提取工艺,以期建立海燕皂苷微波提取方法的最佳工艺条件。由实验结果可知:微波提取的优化条件为:微波功率600W,提取时间5min,溶剂为95%的乙醇,料液比1︰10。海燕总皂苷提取率为1.95%。     

Biosorption of As(III) and As(V) from Aqueous Solution by Lichen (Xanthoria parietina) Biomass

The biosorption of As(III) and As(V) from aqueous solution on lichen (Xanthoria parietina) biomass were investigated using different experimental parameters such as solution pH, biomass concentration, contact time, and temperature. The equilibrium data were evaluated by Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm models. The biosorption capacity of X. parietina for As(III) and As(V) was found to be 63.8 mg/g and 60.3 mg/g. The mean sorption energy values calculated from D–R model indicated that the biosorption of As(III) and As(V) onto X. parietina biomass took place by chemical ion-exchange. The thermodynamic parameters showed that the biosorption of As(III) and As(V) ions onto X. parietina biomass was feasible, spontaneous, and exothermic in nature. Kinetic examination of the sorption data revealed that the biosorption processes of both As(III) and As(V) followed well the pseudo-second-order kinetics. The arsenic ions were desorbed from X. parietina using both 1 M HCl and 1 M HNO₃. The recovery yield of arsenic ions was found to be 80-90% and the biosorbent had good reusability after consecutive seven sorption-desorption cycles.     

对氨基苯乙醇合成新工艺研究

研究了β-苯乙醇为原料,心血管药物的重要中间体对氨基苯乙醇的合成新工艺。通过酯化、硝化、水解、还原四步反应,对氨基苯乙醇的总摩尔收率达到66.4%,含量为99.77%(HPLC法)。产物结构经熔点、GC-MS确证。新工艺具有很大工业化应用价值。     

微乳化含水乙醇汽油及其乳化剂最佳HLB值研究

实验研究了油、乙醇、水三者含量对含水乙醇汽油体系的影响关系,探讨含水乙醇汽油的相分离机理,应用微乳化理论优选和复配乳化剂,研究含水乙醇汽油乳化剂的最佳HLB值及乙醇含量、水含量对含水乙醇汽油乳化剂最佳HLB值的影响关系。试验结果表明：混合燃料的稳定性随水含最增加而下降,随乙醇含量的增加而上升;含水乙醇汽油乳化剂的最佳HLB值在5．5～6．5之间;且含水乙醇汽油乳化剂的最佳HLB值随水含量的增加有降低的趋势,受乙醇含量的影响不显著。     

玉米芯稀酸预处理和分步糖化与发酵工艺生产燃料乙醇的中试研究

利用正交试验在中试水平考察了玉米芯的稀硫酸预处理和分步糖化与水解生产乙醇的工艺。结果:最佳预处理工艺为稀硫酸浓度1.1%,温度120℃,固液比1∶8,时间3 h;酶解糖化最佳工艺为:起始底物浓度180 g/L,滤纸酶活:纤维二糖酶活=20 IU/g底物:7 IU/g底物,pH=5.0,48 h;利用运动发酵单胞菌发酵酶解液,35℃,48 h,发酵液中乙醇浓度最高67.8 g/L。     

Removal of As(III) from Aqueous Solution Using Functionalized Ultrafine Iron Oxide Nanoparticles

Arsenic toxicity has become a major concern worldwide. Remediation of this problem needs the development of technology with improved materials and systems with high efficiency. We have demonstrated a simple and efficient method for the absolute removal of As(III) from high concentration As(III) treated water with a low contact time period. The process of As(III) adsorption follows pseudo-second-order kinetic model. The mechanism for high-adsorption efficiency is attributed to fatty acid binding domain-mediated surface conjugation of ultrafine Fe₂O₃ nanoparticles with As(III). We have also ensured the simultaneous separation of arsenic sorbed nanoparticles by entrapping them in hydrophilic calcium alginate beads and thereby a pure arsenic free solution has been obtained.     

Alteration of Ethanol Reward by Prior Mephedrone Exposure: The Role of Age and Matrix Metalloproteinase-9 (MMP-9)

Mephedrone, a synthetic cathinone, is widely abused by adolescents and young adults. The aim of this study was to determine: (i) whether prior mephedrone exposure would alter ethanol reward and (ii) whether age and matrix metalloproteinase-9 (MMP-9) are important in this regard. In our research, male Wistar rats at postnatal day 30 (PND30) received mephedrone at the dose of 10 mg/kg, i.p., 3 times a day for 7 days. To clarify the role of MMP-9 in the mephedrone effects, one mephedrone-treated group received minocycline, as an MMP-9 antagonist. Animals were then assigned to conditioned place preference (CPP) procedure at PND38 (adolescent) or at PND69 (adult). After the CPP test (PND48/79), expression of dopamine D1 receptors (D1R), Cav1.2 (a subtype of L-type calcium channels), and MMP-9 was quantified in the rat ventral striatum (vSTR). The influence of mephedrone administration on the N-methyl-D-aspartate glutamate receptors (NMDAR) subunits (GluN1, GluN2A, and GluN2B) was then assessed in the vSTR of adult rats (only). These results indicate that, in contrast with adolescent rats, adult rats with prior mephedrone administration appear to be more sensitive to the ethanol effect in the CPP test under the drug-free state. The mephedrone effect in adult rats was associated with upregulation of D1R, NMDAR/GluN2B, MMP-9, and Cav1.2 signaling. MMP-9 appears to contribute to these changes in proteins expression because minocycline pretreatment blocked mephedrone-evoked sensitivity to ethanol reward. Thus, our results suggest that prior mephedrone exposure differentially alters ethanol reward in adolescent and adult rats.