离子液体中结晶分离熊果酸和齐墩果酸研究

为拓展结晶溶剂的范围和提高结晶分离熊果酸和齐墩果酸的性能,引入离子液体作为结晶溶剂。测定了熊果酸和齐墩果酸在六种离子液体+乙醇溶液中的溶解度数据,根据该数据,选取1-辛基-3-甲基咪唑六氟磷酸+乙醇混合溶液作为溶剂对熊果酸和齐墩果酸进行了结晶分离,并采用单因素实验对结晶工艺进行了初步优化。结果表明：在1-辛基-3-甲基咪唑六氟磷酸质量分数5%,熊果酸和齐墩果酸质量比1.5∶1,结晶温度30℃,结晶时间14 h的条件下,结晶产物中齐墩果酸的质量分数可以达到85%左右。     

齐墩果酸-苯甲醛缀合物的合成及抗肿瘤活性研究

以天然产物齐墩果酸为起始原料,将苯甲醛通过酯化反应拼接到齐墩果酸的C28位,合成了齐墩果酸-苯甲醛缀合物,其结构通过~1H NMR进行了确证。同时,探讨了不同酯化反应条件对产率收率的影响。确定了最佳反应条件为:物料比n_(DMAP)∶n_(EDC)∶n_(OA)=0.5∶5∶1、反应时间为24h,缀合物的产率最高。随后,通过初步的活性测试结果表明,齐墩果酸-苯甲醛缀合物对HepG2、MCF-7、PC3和HeLa均有明显的抑制活性,并强于先导化合物齐墩果酸和苯甲醛;此外,齐墩果酸-苯甲醛缀合物对正常的MCF-10A细胞没有毒性。     

超声波辅助提取枇杷叶中齐墩果酸工艺研究

以枇杷叶为原料,以齐墩果酸得率为指标,采用超声波辅助提取了枇杷叶中齐墩果酸.分别研究了乙醇浓度、料液比、超声时间、超声温度对齐墩果酸提取率的影响,通过正交实验优化了提取工艺.结果表明,齐墩果酸提取的最佳工艺条件是:乙醇浓度80%、料液比1:14、超声时间30min、超声温度60℃,在最佳条件下,齐墩果酸得率可达0.37...     

响应面法优化女贞子中齐墩果酸提取工艺的研究

为优化女贞子齐墩果酸提取工艺,采用微波辅助提取女贞子中齐墩果酸,以响应面法试验设计对结果进行优化分析。结果表明:乙醇体积分数82%、料液比1∶11 g/mL、微波时间3 min、微波功率300 W、微波温度58℃,在此最优条件下,齐墩果酸提取率达2.8589%。     

超临界CO2流体萃取中华雪胆中齐墩果酸的研究

采用正交实验优化中华雪胆中齐墩果酸的萃取工艺条件,考察了萃取压力、温度、时间、CO2流量、夹带剂种类及用量对萃取率的影响,确定了超临界CO2流体萃取中华雪胆中齐墩果酸的最佳条件如下:萃取压力40 MPa,萃取温度55℃,无水乙醇为夹带剂,用量为5%,萃取时间为2 h,CO2流量为20kg·h1.与传统有机溶剂提取法相比,用超临界CO2流体萃取齐墩果酸,不仅方法简便、安全,而且提取的选择性与效率更高.     

肝喜乐颗粒中齐墩果酸含量测定方法的改进

目的：改进肝喜乐颗粒中齐墩果酸含量测定方法。方法：HPLC法,,以乙醚、乙醇为提取溶剂,乙腈-水-冰醋酸-三乙胺（75：25：0.5：0.1）为流动相,检测波长为208nm。结果：线性回归方程为Y=654179X-6734.6,r=0.9998,齐墩果酸在2.8μg～5.6μg范围内呈良好线性关系。精密度试验RSD=1.04%,稳定性试验24h内,RSD=1.51%,重复性试验RSD=1.2%。齐墩果酸的平均回收率为99.20%,RSD=1.79%（n=6）。结论该方法准确可靠,适用于肝喜乐颗粒中齐墩果酸的含量测定。     

HPLC法测定陆英中乌索酸和齐墩果酸含量

用SymmetryC18色谱柱,流动相甲醇 水(88∶12),检测波长220nm,流速0.6mL/min,柱温25℃,测定陆英药材中乌索酸和齐墩果酸含量。试验结果表明:峰面积RSD(相对标准差值)均小于2.5%,乌索酸和齐墩果酸平均回收率分别为98.32%(RSD为2.12%)和97.92%(RSD为1.69%)。本法可同时测定乌索酸和齐墩果酸含量,具有准确、灵敏、数据可靠的优点,可用于陆英药材质量控制。     

3β-(4-羟基肉桂酰)氧基齐墩果酸衍生物合成的研究

以对羟基肉桂酸为起始原料经甲酯化,苄基保护酚羟基酯水解得苄氧基肉桂酸,经水解得对苄氧基肉桂酸再与齐墩果酸成酯,经脱苄基保护得3β-(4-羟基肉桂酰)氧基齐墩果酸衍生物,总收率为39.6%。其结构均经1H NMR和MS确认。     

超临界CO2萃取八月瓜果皮中齐墩果酸条件优化

采用超临界CO2萃取技术从八月瓜果皮中萃取齐墩果酸,采用单因素试验和正交试验分析了无水乙醇(夹带剂)添加比例、原料粉碎细度、萃取温度和萃取压力对萃取得率的影响,确定了萃取的最佳工艺条件。结果表明:利用超临界CO2萃取八月瓜果皮中齐墩果酸的最佳工艺条件为固液比(乙醇添加比例)1:2.5、原料细度100目、萃取温度45℃、萃取压力35MPa,此条件下齐墩果酸萃取得率为0.184%。     

正交优化微波辅助提取女贞子中齐墩果酸的工艺研究

以女贞子为原料,采用微波辅助提取女贞子中齐墩果酸,在单因素实验基础上,通过正交试验对工艺条件进行了优化。结果表明,最佳提取条件是：乙醇浓度为90％,料液比为1：10（g／mL）,微波时间为3min,微波功率为400W,微波温度为60℃。在此条件下,齐墩果酸提取率为2．518％。     

Anti-Inflammatory Activity of Three Triterpene from Hippophae rhamnoides L. in Lipopolysaccharide-Stimulated RAW264.7 Cells

Oleanolic acid (OA), asiatic acid (AA), and maslinic acid (MA) are ubiquitous isomeric triterpene phytochemicals with many pharmacological effects. To improve their application value, we used lipopolysaccharide (LPS) to induce RAW264.7 cells and studied the differences in the anti-inflammatory effects of the triterpenes according to their structural differences. MTT, Griess, and immunofluorescence assays, ELISA, flow cytometry, and Western blotting, were performed. The release of LPS-induced pro-inflammatory mediators, such as nitric oxide (NO), inducible nitric oxide synthase (iNOS), and interleukin (IL-6), was significantly inhibited by OA, AA, and MA at the same concentration, and AA and MA promoted the production of anti-inflammatory factor IL-10. OA, AA, and MA inhibited LPS-induced NF-κB nuclear translocation in RAW264.7 cells. OA and AA inhibited the phosphorylation of ERK1/2, P38, and JNK1/2 in LPS-stimulated RAW264.7 cells. Moreover, OA increased LPS-induced Nrf2 expression and decreased Keap1 expression in RAW264.7 cells. OA, AA, and MA inhibited LPS-stimulated intracellular reactive oxygen species (ROS) production and alleviated mitochondrial membrane potential depletion. Overall, our data suggested that OA, AA, and MA exhibited significant anti-inflammatory effects in vitro. In particular, OA and AA take effects through the MAPKs, NF-κB, and Nrf2 signaling pathways.     

二水法改二水-半水法生产湿法磷酸的技术改造

通过提高磷酸浓度和降低磷石膏中P2O5含量,达到降低浓缩能耗和提高磷石膏质量,满足水泥生产的要求。介绍该厂将二水法生产磷酸工艺改造为二水-半水法工艺的流程、新增设备、工艺指标及技术要点。技改后,磷酸w(P2O5)由22%提高到35%,磷石膏中w(P2O5)由1.5%下降到0.2%以下,磷石膏中的w(H2O结晶)由14%～16%下降到4%～8%,每年节煤约1.5万t,综合新增效益1786万元。     

不对称转换方法制备D-型氨基酸

简述了D－型氨基酸的方法，化学不对称转换，生物不对称转换方法，制备D－型氨基酸的一般方法是先制备外消旋体，再进行拆分。根据拆分的手段和途径不同，分为物理拆分，化学拆分，生物拆分等。化学不对称转化是以L－型氨基酸或DL－型氨基酸为原料在拆分剂和催化剂共同存在下加热得到D－型氨基酸与拆分剂形成的盐，后者与碱反应得到D－型氨基酸。生物不对称转换包括两种情况，（1）不对称降解，即首先把DL－氨基酸衍生化。然后利用微生物产生的酶使氨基酸衍生物不对称水解。（2）水制备某一外消旋中间体，然后通过微生物体产生的消旋酶和水解酶在一定条件下使外消旋中间体转变为D－型氨基酸。     

Lactose fermentation in the presence of C18 fatty acids

Lactose degradation in the presence of C₁₈ long chain fatty acids was examined under anaerobic conditions at 37 °C. The lactose degradation rate was a function of linoleic acid (LA) and oleic acid (OA) concentrations but independent of the amount of stearic acid (SA) added. In cultures fed with LA, lactose was removed within approximately 12 h and within 6 h for cultures inoculated with OA or SA. Glucose, a product of lactose degradation, was only observed in cultures fed with 500–700 mg dm^?3 LA and 1000 mg dm^?3 OA. No galactose was detected under any of the conditions examined. The cause of glucose accumulation is likely due to inhibition of acidogens by LA and OA. Lactate was detected under all conditions examined. LA was more inhibitory on lactate‐consuming organisms than OA and SA and larger amounts of lactate were observed in cultures fed with LA. In addition to lactate, butyrate, propionate and acetate were also observed. Accumulation of volatile fatty acids was a function of the type and concentration of long chain fatty acids. In cultures fed with SA, lower levels of butyrate and acetate were observed when compared with those inoculated with LA and OA and no propionate was detected. Copyright © 2004 Society of Chemical Industry     

Photocatalytic degradation of model organic pollutants on an immobilized particulate TiO2 layer: Roles of adsorption processes and mechanistic complexity

The kinetics of photocatalytic degradation of four different model organic compounds, formic acid (FA), oxalic acid (OA), 4-chlorophenol (4-CP) and the herbicide monuron (3-(4-chlorophenyl)-1,1-dimethylurea) in a self-constructed batch-mode plate photoreactor with a thin flow of contaminated aqueous solution circulating over an illuminated particulate layer of TiO₂ P25 (Degussa) was compared. Both OA and FA were adsorbed on TiO₂ surface; their mineralization, induced by direct transfer of photogenerated holes, proceeded in a single step, without observable intermediates, following approximately zero order kinetics. Numerical simulations were performed using a newly proposed kinetic model based on the photostationary state assumption. The model allowed an explanation of the observed reaction order as well as the comparison of independent with competitive adsorption of organic compound and oxygen on the photocatalyst surface, yielding a better fit for the case of competition. 4-CP and monuron, which were not adsorbed under the conditions used, were degraded through the action of photogenerated hydroxyl radicals. Their degradation proceeded with lower photoefficiency than for the adsorbed compounds (FA and OA). While the mineralization of both 4-CP and monuron followed zero order kinetics, their degradation was close to first order. The different reaction orders were consistently explained using the photostationary state approach.     

Influence of C18 long chain fatty acids on butyrate degradation by a mixed culture

Butyrate degradation in the presence of C₁₈ long chain fatty acids (LCFAs) was examined under anaerobic conditions at 21 °C. Butyrate degradation rates were a function of linoleic acid (LA) and oleic acid (OA) concentration but independent of the amount of stearic acid (SA) added. Within 2–4 h, butyrate reached undetectable levels in the control cultures. However, in cultures fed with LA, butyrate was removed within between 12 and 25 h and within 2–12 h for cultures inoculated with OA or SA. Propionate was detected in cultures fed with 50 mg dm^?3 LA and in cultures inoculated with OA and SA. LA exerted a greater inhibitory effect on butyrate‐degrading organisms than OA and SA with longer removal times observed in cultures fed with LA. The propionate and acetate removal times and quantity produced were not related to the type and concentration of LCFA. Copyright © 2004 Society of Chemical Industry     

A kinetic study of the electrochemical oxidation of maleic acid on boron doped diamond

Maleic acid (MA) is one of the main intermediates formed during mineralization, by electrooxidation, of aromatic compounds contained in aqueous wastes. This work investigates oxidation of maleic acid with or without the presence of oxalic acid (OA) and formic acid (FA) in aqueous solution by using boron-doped diamond (BDD) electrodes. OA and FA are the main products formed in MA electrooxidation. Voltammetric studies conducted with a BDD electrode of small surface (0.196 cm²) show that MA oxidation takes place at a potential very close to that of the discharge of water. But, under potentiostatic conditions and at concentrations higher than 0.001 M, adsorption of MA blocks its own oxidation. Oxalic and formic acids are before the discharge of water. Again, the presence of maleic acid blocks the oxidation of formic and oxalic acids. Galvanostatic electrolyses of aqueous solutions of MA, OA, FA and mixtures of theses acids were conducted on a BDD electrode. Electrolyses were controlled by measurements of Total Organic Carbon, Chemical Oxygen Demand and by Liquid Chromatography. Results showed that MA was totally mineralized; FA and OA were very low concentration intermediaries. Electrolyses of solutions containing MA, initially in the presence of OA or FA, showed that the OA was oxidized at the same rate as the MA, whereas the FA oxidation began only when the MA had completely disappeared. These results suggest that OA oxidizes by a mass transport limited process coupled with a direct electron transfer with the anode. Under galvanostatic conditions, maleic acid and formic acid are probably oxidized via OH^· radicals generated by water discharge.     

透明质酸对人骨性关节炎软骨细胞凋亡及细胞周期的影响

目的观察透明质酸(Hyaluronic acid,HA)对人骨性关节炎(Osteoarthritis,OA)软骨细胞凋亡及细胞周期的影响,以探讨HA保护软骨细胞的作用机制。方法分离人正常软骨细胞和OA软骨细胞,传至第2代后,分别经HA处理24 h,采用MTT法检测细胞的增殖活力,流式细胞术检测细胞凋亡率和细胞周期。结果 HA能明显降低人OA软骨细胞的凋亡率(P<0.05),提高细胞的增殖活力、S期比例和增殖指数(P<0.05),且对正常人软骨细胞的增殖活力和凋亡无明显影响。结论 HA可促进OA软骨细胞的分裂与增殖,降低细胞凋亡率,从而对软骨细胞发挥保护作用。     

构型转换法制备赤式紫胶桐酸及反应机理分析

探索了苏式紫胶桐酸制备赤式紫胶桐酸的方法及其反应机理。以苏式紫胶桐酸为原料通过构型转换法制备赤式紫胶桐酸,采用FTIR、质谱、核磁（1H /13C-NMR）、TG、DSC、XRD、手性拆分、旋光性等表征手段对所得产物进行了分析确证。在此基础上,对紫胶桐酸苏式到赤式构型的转换机理进行了初步探究。结果表明：FTIR、质谱、核磁显示产物与苏式紫胶桐酸结构一致;XRD、DSC、TG结果表明苏式与产物具有相同晶型,但产物熔点更高,晶胞尺寸更小;手性拆分结果显示产物为紫胶桐酸的光学异构体,从而确定产物为赤式紫胶桐酸。对中间产物的结构表征表明,紫胶桐酸苏式到赤式构型转换的机理为卤素和羟基之间SN2和E2同时发生的反应,羟基和卤素间的两次SN2反应,是发生构型转换反应（瓦尔登转换）的关键;羟基/卤素的E2反应是苏式紫胶桐酸能够彻底转化为赤式的原因。     

Liquid Phase Selective Catalytic Oxidation of Oleic Acid to Azelaic Acid Using Air and Transition Metal Acetate Bromide Complex

Industrially important di‐carboxylic acids are synthesized from mono‐carboxylic unsaturated and unsaturated fatty acids. In this study, the aim is to perform the simultaneous catalytic oxidative C=C cleavage of oleic acid (OA) to azelaic acid and pelargonic acid, and oxidation of the terminal methyl group in pelargonic acid to azelaic acid using cobalt‐ and manganese‐acetate as catalyst, hydrogen bromide as co‐catalyst and air in acetic acid at elevated pressure (2.8–5.8 barg) and temperature (353–383 K). Oxygen solubility is determined under varying pressure, temperature and OA loading. The effect of OA loading, pressure and temperature on OA conversion and azelaic acid selectivity is studied by varying one variable at a time; however, the presence of the synergistic effect of the catalyst and co‐catalyst is investigated by central composite design assisted response surface methodology. Oxidation of terminal methyl group in saturated fatty acid is also confirmed by the oxidation of stearic acid to octadecanedioic acid using identical oxidation conditions of OA. Oxidation products of fatty acids are quantified by gas chromatographic analysis. The innovation of the work is thus the ability of the catalytic system to perform a total oxidation of a terminal methyl group of the hydrocarbon chain. OA oxidation kinetics relating to catalyst and co‐catalyst concentration along with oxygen solubility at elevated temperature and pressure is established. The frequency factor and activation energy for OA oxidation is determined using the Arrhenius equation.