黄龙胆根黄酮类化合物的提取、纯化工艺研究

通过单因素与正交实验研究了微波辅助乙醇溶剂法提取黄龙胆根黄酮类化合物的最佳工艺条件,优化了大孔树脂对所得黄酮类化合物进行纯化的工艺。得出提取最佳工艺条件为:微波功率300 W,微波时间8 min,乙醇浓度35%,料液比1∶20。在此条件下,得率为32.19%,粗提物总黄酮含量为1.97%。通过静态实验,选出最佳纯化树脂为AB-8大孔树脂;通过动态实验,得出吸附分离黄龙胆根黄酮类化合物工艺参数为:上样液流速2.00 m L/min,洗脱剂流速2.00 m L/min。经纯化后总黄酮含量为20.17%。     

八角莲中黄酮类化合物的分离纯化工艺研究

研究了八角莲中黄酮类化合物的分离纯化工艺。考察各种因素对树脂吸附和洗脱效果的影响,确定了AB-8型大孔树脂分离纯化八角莲中黄酮类化合物的最佳工艺参数。最佳工艺参数为:静态吸附,树脂与样液比为1:20 g/m L、吸附时间为3 h,静态解吸过程解吸液(乙醇)体积分数为70%、树脂与解吸液的比例为1∶50 g/m L;动态吸附中动态流速为0.5 m L/min、静置时间为80 min,动态解吸中洗脱液(乙醇)的体积分数为60%、树脂与洗脱液的比例为1∶40 g/m L。     

大孔树脂对5-羟基色氨酸的吸附研究

筛选适合分离纯化加纳籽中5-羟基色氨酸的树脂,并确定最佳工艺。以5-羟基色氨吸附量和回收率为指标,制定吸附等温线和研究树脂静态吸附动力学,确定大孔树脂型号;动态吸附分离法确定分离条件。对6种树脂进行考察,其中AB-8型大孔吸附树脂对5-羟基色氨酸具有良好的吸附分离性能,其初步分离纯化工艺条件：以浓度10.5mg/mL的样品动态吸附,以50%的乙醇为解吸剂,洗脱流速1.5BV/h,回收率98.79%。结果表明,AB-8型大孔吸附树脂适合分离纯化5-羟基色氨酸,该方法操作简便,利于实际的生产。     

AB-8大孔树脂纯化柑橘皮总黄酮的研究

通过静态吸附解吸实验以及动态吸附解吸实验,优化了AB-8大孔树脂纯化柑橘皮黄酮的工艺。结果表明,AB-8大孔树脂的静态吸附:饱和吸附量15 mg/g(以树脂湿重计),饱和吸附时间180 min,样液最佳p H 5. 5,样液中黄酮浓度高有利于吸附; AB-8大孔树脂的静态解吸液乙醇最佳浓度为80%,黄酮解吸速度很快,少量解吸液可较好地洗脱而得到高浓度黄酮溶液;动态吸附流速3 BV/h,解吸流速6 BV/h,纯化柑橘黄酮的回收率为75. 07%,纯化倍数为4. 14;柑橘皮黄酮主要以糖苷形式存在,苷元较少。     

大孔树脂纯化茶皂素的工艺研究

采用静态吸附实验考察了D-101、DM-301、AB-8、D001、D201、D113、D202等大孔树脂对茶皂素的纯化效果,并考察了上样速度、溶剂体积、上样液质量浓度对大孔树脂AB-8动态吸附率的影响以及洗脱液浓度、洗脱速度、洗脱剂体积对动态洗脱率的影响。大孔吸附树脂AB-8纯化茶皂素的最佳工艺条件为:上样液浓度为27 mg/mL,流速为2.5 mL/min,洗脱剂为75%乙醇,用量为上样液体积的2倍,洗脱速度为2.5mL/min,可以得到纯度为85.7%的茶皂素。     

大孔树脂纯化茶皂素的工艺研究

采用静态吸附实验考察了D-101、DM-301、AB-8、D001、D201、D113、D202等大孔树脂对茶皂素的纯化效果,并考察了上样速度、溶剂体积、上样液质量浓度对大孔树脂AB-8动态吸附率的影响以及洗脱液浓度、洗脱速度、洗脱剂体积对动态洗脱率的影响。大孔吸附树脂AB-8纯化茶皂素的最佳工艺条件为:上样液浓度为27 mg/mL,流速为2.5 mL/min,洗脱剂为75%乙醇,用量为上样液体积的2倍,洗脱速度为2.5mL/min,可以得到纯度为85.7%的茶皂素。     

AB-8大孔树脂纯化柑橘皮总黄酮的研究

通过静态吸附解吸实验以及动态吸附解吸实验,优化了AB-8大孔树脂纯化柑橘皮黄酮的工艺。结果表明,AB-8大孔树脂的静态吸附:饱和吸附量15 mg/g(以树脂湿重计),饱和吸附时间180 min,样液最佳p H 5. 5,样液中黄酮浓度高有利于吸附; AB-8大孔树脂的静态解吸液乙醇最佳浓度为80%,黄酮解吸速度很快,少量解吸液可较好地洗脱而得到高浓度黄酮溶液;动态吸附流速3 BV/h,解吸流速6 BV/h,纯化柑橘黄酮的回收率为75. 07%,纯化倍数为4. 14;柑橘皮黄酮主要以糖苷形式存在,苷元较少。     

大孔树脂混用技术分离纯化竹叶黄酮的工艺研究

采用大孔树脂混合使用技术,用于分离纯化竹叶黄酮的工艺研究。通过研究8种大孔树脂对竹叶黄酮的静态吸附与解吸实验,筛选出两种较好的树脂D101-1和AB-8,采用混用技术进行实验,结果表明:D101-1与AB-8的最优混合比例为2:1;上样液质量浓度1.2 mg/m L、上样量为3.5 BV、上样流速2 BV/h为最佳上样条件,洗脱剂体积分数70%、洗脱体积4BV、洗脱流速2 BV/h的条件下进行洗脱。在此条件下进行纯化实验,分离纯化效果最好,样品中黄酮纯度由原来的8.46%上升至28.16%。     

大孔吸附树脂对喜树叶中喜树碱的纯化工艺研究

研究通过静态吸附/解吸实验对大孔吸附树脂进行筛选,优选AB-8大孔吸附树脂作为层析柱填料,并对其进行喜树碱纯化工艺研究;研究表明AB-8树脂对喜树碱的静态吸附率为95.31%;体积分数95%的乙醇静态解吸率为92.4%;最佳吸附条件为:上样液质量浓度为0.175mg/mL,上样液不调pH值,吸附流速为2BV/h,平衡吸附5h;最佳洗脱条件:体积分数95%乙醇,洗脱流速1BV/h,洗脱体积为8BV。在该工艺条件下,洗脱物中喜树碱质量分数为7.43%,洗脱率为83.1%。     

大孔吸附树脂分离纯化马缨丹总黄酮的工艺研究

探讨大孔吸附树脂纯化马缨丹总黄酮的最佳工艺,通过对4种型号大孔树脂的静态实验,筛选出最佳树脂;考察最佳树脂对马缨丹总黄酮的吸附及洗脱性能,优化工艺参数。结果表明:AB-8为最佳树脂,其最佳工艺条件为:上样液质量浓度0.198 mg/mL,吸附流速为2.0 mL/min,吸附pH为4.0;洗脱剂为70%乙醇,洗脱用量5 BV,减压浓缩得马缨丹总黄酮浸膏,纯度为32.45%。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.