云南竹灵芝中的总黄酮的提取研究

本实验主要研究了超声波辅助提取云南竹灵芝中总黄酮的提取工艺,先通过单因素实验确定料液比、超声时间、乙醇浓度、超声温度对灵芝中总黄酮提取效果的影响,再利用正交实验法优化得出最佳提取工艺条件。根据正交实验的结果,各因素对灵芝中总黄酮的提取影响由大到小依次为料液比乙醇浓度超声温度超声时间,最佳提取工艺为料液比1∶50,超声时间60 min,乙醇浓度70%,超声温度50℃。此时竹灵芝中总黄酮的得率可达7.269 mg/g。     

响应面法优化翠云草总黄酮的提取工艺

以翠云草为原料,采用超声辅助提取翠云草总黄酮,研究提取时间、乙醇浓度、液料比对总黄酮提取率的影响,以单因素实验为基础,利用响应面法优化翠云草总黄酮提取工艺。结果表明:翠云草总黄酮的最佳工艺条件为提取时间40 min、乙醇浓度70%、液料比25︰1(m L/g),此时翠云草总黄酮的提取率为1.138%,与模型方程理论预测值1.154%接近。     

正交实验法优选香加皮中总黄酮的提取工艺

通过正交实验法,优选香加皮药材中总黄酮的最佳提取工艺。以香加皮中总黄酮的提取率作为指标,采用超声辅助法对香加皮药材中总黄酮进行提取,以乙醇浓度(A)、超声时间(B)、温度(C)三个提取条件进行单因素实验,在单因素实验的基础上,设计三因素三水平的正交试验。对香加皮中总黄酮提取影响最大的因素是温度,超声辅助法提取香加皮总黄酮的最佳条件为:乙醇浓度90%,温度60℃,超声时间为35 min,药渣重复提取一次。在此工艺条件下香加皮中总黄酮的提取率为2.313%。用超声辅助法进行香加皮总黄酮提取操作简便、提取率高,此数据结果可为香加皮的进一步研究提供理论依据。     

金盏银盘总黄酮提取工艺研究

对从金盏银盘中提取总黄酮的工艺进行了优化:首先以金盏银盘总黄酮的含量为考察指标,比较了乙醇回流提取和超声提取方法;接着采用L9(34)正交试验,以金盏银盘总黄酮含量为考察指标,考察了乙醇浓度、乙醇用量、提取时间、提取温度4个因素对提取总黄酮的影响。结果表明:超声提取法优于回流提取法,最优的提取工艺是用20倍量的70%的乙醇在60℃的温度下超声提取两次,每次提取1.5 h。该工艺操作简单,结果可靠,为金盏银盘总黄酮的提取和金盏银盘的进一步开发奠定了基础。     

永州荔枝草总黄酮超声提取工艺及抗氧化活性研究

以永州野生荔枝草为对象,在测定总黄酮含量基础上,采用正交试验确定最佳提取工艺,进一步研究总黄酮提取物的抗氧化活性。实验结果表明,荔枝草中总黄酮含量为7. 32%;最佳提取工艺条件为:乙醇浓度70%、料液比1∶15、超声温度30℃、超声时间50 min,总黄酮得率为5. 40%,总黄酮提取率达到73. 77%。荔枝草总黄酮提取物清除DPPH自由基活性较强,且有良好的线性关系。     

响应曲面法优化野菊花中总黄酮的超声提取工艺

以总黄酮得率为评价指标,采用单因素实验和响应曲面法实验优化野菊花中总黄酮超声提取工艺。确定最佳提取工艺为:乙醇体积分数60%、超声提取时间40min、液料比15∶1(mL∶g)、超声提取温度50℃、超声功率1 080 W,在此条件下,总黄酮得率可达0.881%。该提取工艺设计合理,为进一步研究野菊花中总黄酮的应用提供了科学依据。     

葛根总黄酮的提取研究

用超声辅助提取葛根总黄酮,考察了超声功率、超声作用时间、提取温度和乙醇浓度等因素对葛根总黄酮提取率的影响。结果表明,超声提取葛根总黄酮的较佳工艺条件为:超声功率270 W,超声作用时间20 min,提取温度70℃,乙醇浓度为65%,此条件下总黄酮提取率为167.974 mg/100 g葛根粉。     

山楂核总黄酮的超声提取及抗氧化活性

采用超声辅助乙醇提取山楂核总黄酮,通过单因素实验方法和正交实验方法确定了总黄酮的最优提取工艺条件;与抗坏血酸、芦丁对比,利用羟基自由基(·OH)、1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、Fe3+法测定山楂核总黄酮的抗氧化活性。结果表明,山楂核总黄酮超声辅助提取的最佳提取工艺为:按料液比为1∶25(每克山楂核加入25 m L提取剂,下同),加入体积分数50%的乙醇,在60℃下用250 W超声辅助提取40 min,山楂核中总黄酮的提取率可达到7.89%。经过纯化的山楂核总黄酮提取物对·OH和DPPH·具有明显的清除力且对Fe3+有较强的还原能力;黄酮纯化物的抗氧化作用随质量浓度增大而增强,其抗氧化能力强于芦丁而弱于抗坏血酸。     

银杏叶总黄酮提取条件研究

利用超声辅助乙醇水溶液提取银杏叶中总黄酮,首先对影响黄酮提取率的四个因素:提取温度(A)、提取时间(B)、固液比(C)、乙醇浓度(D),进行单因素探索,然后在单因素实验的基础上,每个因素选3个水平进行正交实验,结果表明:最佳工艺条件为:70%的乙醇作溶剂,1∶30的固液比,保持75℃下超声20 min。此工艺条件下总黄酮提取率为2.781%。     

响应面法优化天山堇菜总黄酮的提取工艺

采用响应面法优化超声波提取新疆天山堇菜中总黄酮的工艺条件。采用Box-Behnken中心组合设计及响应面法分析提取时间、料液比、乙醇浓度、超声次数对天山堇菜中总黄酮的超声提取工艺的影响,筛选最佳条件。提取最优条件为超声70 min,液料比27∶1,乙醇浓度为55%,超声次数为3次,总黄酮提取率预测值为6.27%。在最优条件下进行三次验证试验,总黄酮的平均得率为6.29%。响应面回归方程与试验结果拟合性好,可用于天山堇菜中总黄酮的提取工艺优化。     

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

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.     

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.     

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.