不同产地不同部位巫山淫羊藿中黄酮的HPLC分析

建立HPLC梯度洗脱法同时测定巫山淫羊藿中3种黄酮:淫羊藿次苷Ⅰ,朝藿定C和淫羊藿苷质量分数的方法。采用HPLC法,色谱柱为phenomenex C18分析柱(5μm,4.6 mm×250 mm);流动相为(A)水,(B)乙腈;柱温35℃;流速1.0 mL/min;检测波长270 nm;线性梯度洗脱条件:B∶15%(5 min),B∶30%(10 min),B∶50%(30 min)。本方法测定淫羊藿次苷Ⅰ,朝藿定C和淫羊藿苷的线形范围在0.20—1.80μg,r=0.999 3,r=0.999 9和r=0.999 7;平均回收率分别为98.43%,97.58%和97.91%,RSD(n=3)分别为2.16%,1.77%和1.90%。该方法简便、准确、重现性好,可作为同时测定淫羊藿次苷Ⅰ,朝藿定C和淫羊藿苷质量分数的方法。     

不同品种淫羊藿的淫羊藿苷含量研究

目的:比较不同品种淫羊藿的淫羊藿苷含量差异。方法:以十八烷基硅烷键合硅胶为填充剂,乙腈-水(30∶70)为流动相,检测波长270 nm,流速1.0 mL/min。结果:柔毛淫羊藿、朝鲜淫羊藿、淫羊藿(产自2个不同地方)的淫羊藿苷含量分别为0.28%、0.14%、0.83%和0.87%。结论:不同品种的淫羊藿所含淫羊藿苷的含量存在较大差异。品种的不同会影响淫羊藿药材的质量。     

RP-HPLC法测定超临界提取物中淫羊藿苷的含量

目的：建立淫羊藿叶超临界提取物中淫羊藿苷的含量测定方法。方法：采用RP-HPLC法,Hypersil ODS C18色谱柱（4.6 mm×250 mm,5μm）,甲醇-0.1%冰醋酸水溶液梯度洗脱,流速1 mL.min-1,检测波长270 nm。结果：淫羊藿苷在0.212～2.12μg进样量范围内线性关系良好,平均加样回收率98.7%,RSD为1.18%（n=6）。结论：该法简便、易操作,适用于淫羊藿超临界提取物中淫羊藿苷的含量测定,可有效地控制淫羊藿超临界提取物的质量。     

粗毛淫羊藿抗炎活性成分研究

目的:研究粗毛淫羊藿的抗炎活性组分。方法:用100 ng·mL~(-1) LPS诱导RAW264.7细胞建立炎症筛选模型,测定促炎细胞因子IL-1β、IL-6、iNOS的m RNA表达变化确定炎症的程度;采用多种色谱方法对粗毛淫羊藿抗炎活性部位进行分离纯化;采用~1H-NMR,13C-NMR,ESI-MS等方法,结合文献数据,鉴定化合物结构。结果:粗毛淫羊藿甲醇提取物经大孔吸附树脂吸附,80%甲醇洗脱得到总黄酮部位,抗炎活性筛选具有抗炎活性,从中分离得到6个黄酮类化合物(1-6),结构分别鉴定为大花淫羊藿苷B(1),4"-鼠李糖基淫羊藿次苷Ⅱ(2),淫羊藿次苷Ⅱ(3),脱水淫羊藿素(4),淫羊藿苷(5),4"-鼠李糖基淫羊藿次苷Ⅱ(6),其中化合物2,3,4为首次从粗毛淫羊藿中分离得到。这些化合物都具有一定的抗炎活性。结论:总黄酮和化合物(1-6)对LPS诱导升高的促炎因子表达均具有下调作用,说明黔产粗毛淫羊藿总黄酮具有一定的抗炎活性,其活性成分为其中的黄酮和黄酮苷。     

淫羊藿总黄酮提取物树脂纯化工艺条件的优化

以D1400大孔树脂、HZ-841大孔树脂、PA03060聚酰胺树脂,通过动态吸附与洗脱,对淫羊藿总黄酮提取物进行纯化,HZ-841大孔树脂的纯化效果最优。通过正交试验得到最佳纯化工艺条件为:2g HZ-841大孔树脂,上样总黄酮含量2mg/mL的提取液30mL,分别以80mL水、40mL 20%乙醇、40mL85%乙醇和20mL 95%乙醇进行梯度洗脱,流速1.5mL/min。最优条件下,利用HZ-841树脂纯化淫羊藿总黄酮提取液,得到干浸膏收率3.25%,其中总黄酮含量71.8%,淫羊藿苷含量9.44%。     

HPLC法测定不同产地淫羊藿药材中朝藿苷丙的含量

目的:建立高效液相色谱测定朝藿苷丙含量的方法。方法:采用Agilent Zorbax SB-C18柱,流动相为乙腈和水,检测波长270nm。结果:朝藿苷丙进样量0.02~2.00范围内线性良好,r=0.9996(n=6),加样回收率98.49,RSD=1.11%;10批淫羊藿药材中朝藿苷丙的含量为0.02%~0.88%。结论:朝藿苷丙为淫羊藿药材中的特征成分,其提取及含量测定方法操作简便,结果可靠,可作为淫羊藿药材质量控制的指标性成分。     

超声波法提取淫羊藿中淫羊藿苷工艺研究

对超声波辅助提取淫羊藿中淫羊藿苷进行研究,以淫羊藿苷为考察目标,系统考察了超声波频率、乙醇浓度、超声提取时间、料液比四个因素对提取效果的影响。通过正交实验初步确定最佳提取工艺条件为:90%乙醇,超声波功率900 W,提取时间60 min,料液比1∶20。     

巫山淫羊藿不同药用部位有效成分分析研究

比较研究巫山淫羊藿不同药用部位有效成分含量的差异,为不同药用部位的应用提供合理依据。采用高效液相色谱法检测朝藿定A、朝藿定B、朝藿定C、淫羊藿苷的含量,以乙腈-水作为流动相等梯度洗脱,流速为1.0mL/min,检测波长为270nm。结果显示,不同药用部位中4种化学物质含量存在一定的差异,叶片中4种化合物含量最高。这表明巫山淫羊藿不同药用部位的内在质量存在差异,这为巫山淫羊藿药材的应用提供可靠支撑。     

淫羊藿素的化学合成和结构修饰研究进展

淫羊藿素是天然淫羊藿属植物主要活性成分淫羊藿苷的苷元,是淫羊藿苷在体内发挥疗效的主要形式,具有多种药理活性。目前,淫羊藿素在中国已上市,主要用于不适合或患者拒绝接受标准治疗,且既往未接受过全身系统性治疗、不可切除的肝细胞癌的治疗。由于天然来源的淫羊藿素含量低,限制了对淫羊藿素的研究。因此,研究人员发展了多种淫羊藿素的化学合成方法。此外,人们还针对淫羊藿素的低生物活性、低水溶性等缺点进行结构修饰,得到了多种活性较好的淫羊藿素衍生物。总结了关于淫羊藿素的化学合成方法及结构修饰的文献报道,期望对淫羊藿素的后续研究提供帮助。     

淫羊藿苷提取工艺优化

通过正交实验优选淫羊藿苷的提取工艺,确定优化提取工艺条件为:60%乙醇、液固比为10∶1、提取1次、提取时间1.5 h,在此条件下淫羊藿苷的提取率为91.98%.     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.