不同方法提取枇杷仁油的对比研究

以枇杷仁为原料,对两种提取枇杷仁油的工艺和效果进行比较。通过正交试验得到溶剂法提取枇杷仁油的最佳工艺条件为:溶剂选用石油醚,料液比1︰8(g︰m L),提取时间2 h,提取温度80℃,枇杷仁油提取率为10.3%;超声波辅助法提取枇杷仁油的最佳工艺条件为:溶剂选用石油醚,料液比1︰5(g︰m L),超声温度60℃,超声时间25 min,超声功率180 W,枇杷仁油提取率为12.9%。结果表明,超声波辅助法提取的枇杷仁油得率比溶剂法高,并且超声波辅助法比溶剂法提取的时间短、温度要低,是一种短时高效的提取方法。     

夏枯草总黄酮提取方法的比较

比较醇浸渍提取法、醇溶剂回流提取法、超声辅助醇提取法三种方法下夏枯草总黄酮的提取率,确定最佳提取方法,并通过单因素和正交实验法对超声辅助醇提取法的工艺条件进行优化。结果表明,三种方法的提取率分别为4. 22%、5. 34%、5. 96%。经综合考虑,建议使用超声辅助醇提取法,其最佳提取工艺为:乙醇体积分数为65%、提取时间为20 min、料液比为1∶20,提取率为7. 01%。该研究将为夏枯草总黄酮的提取及开发利用提供了理论依据。     

赶黄草中槲皮素的提取工艺研究

目的:优选赶黄草中槲皮素的提取工艺。方法:分别用回流提取法、超声提取法和冷浸法,提取赶黄草中的槲皮素。回流法采用单因素试验分别考察回流时间、乙醇浓度对提取率的影响;超声提取法采用单因素试验分别考察超声时间、乙醇浓度对提取率的影响;冷浸法考察乙醇浓度对提取率的影响;以槲皮素提取率为指标,提取率越高,提取工艺效果越好;用紫外分光光度法对不同提取工艺中槲皮素的含量进行测定。结果:超声法最佳提取工艺为:80%的乙醇超声提取30 min,回流法最佳提取工艺为:80%的乙醇回流提取4 h;冷浸法最佳提取工艺为:80%的乙醇浸渍36 h。结论:回流法提取赶黄草中槲皮素的提取率最高。     

超临界CO2萃取万寿菊籽油的工艺研究

本文运用超临界CO2萃取技术提取万寿菊籽油,采用正交设计实验法,研究了温度、压力、萃取时间及CO2流量对籽油提取率的影响,以提取率最大为目标,确定了最佳工艺条件,并对万寿菊籽油进行了感官评定.实验结果表明最佳提取条件萃取时间3h,压力35MPa,温度40℃,CO2流量在20～40kg·h-1.籽油透明、橙黄、无异味,酸价为46.93mg KOH/g油,碘值为50.17g/100g.     

香蒲雌花序中总黄酮的提取工艺研究

为获得乙醇浸提法提取香蒲雌花序中总黄酮的最佳工艺,以总黄酮提取率为评价指标,基于单因素试验法考察了乙醇浓度、料液比、回流提取时间对提取率的影响,并以正交实验法进行工艺条件优化.结果表明,最佳提取工艺为乙醇浓度50％,料液比1∶50(g∶mL),回流提取时间1h,此条件下香蒲雌花序中总黄酮的提取率可达3.45％.     

正交实验优化啤特果中总黄酮提取工艺

通过吸光度的测定方法以及单因素实验法和正交实验法确定啤特果总黄酮的最佳提工艺取条件,使用乙醇回流法优化啤特果总黄酮的提取工艺。通过数据处理得到影响啤特果总黄酮提取率的因素依次料液比、酒精浓度、提取时间和提取温度,其最佳工艺提取条件为料液比1:25、乙醇浓度70%、提取温度80℃、提取时间3.5 h。在此条件下啤特果总黄酮的提取率为7.95%。     

超声萃取陕西黄姜中姜酚的工艺研究

以陕南汉中和安康种植的黄姜为原料,以乙醚为溶剂,采用超声萃取法提取姜酚,应用正交实验法探索了料剂比、超声温度、超声频率、超声时间对提取效率的影响,并对提取物进行了柱层析分离和UV、IR光谱定性分析.结果表明,超声提取时间是影响提取率的主因,最佳提取条件为：超声提取温度为70℃,姜和溶剂的比为1∶2（g/mL）,提取时间为2h,超声功率为400 W,姜酚提取率最大为2.12％,提取物中纯姜酚的质量分数（纯度）为71.8％.     

蜀葵子脂肪油提取工艺的研究

考察了蜀葵子中脂肪油的提取工艺。通过测定油脂的理化性质优化提取方法,并通过单因素试验和正交试验设计考察提取时间、温度、功率、溶剂、料液比等因素对蜀葵子脂肪油提取率的影响。选择石油醚为最佳提取溶剂,超声为最优提取方法,提取条件为超声功率200 W,超声温度30℃,提取时间40 min,料液比1:10(g/mL),粉碎度为50目,提取次数为1次。在此条件下蜀葵子脂肪油的提取率可达12.57%。优化得到的工艺合理可行,比较适合蜀葵子脂肪油的提取。     

广西小叶榕叶总黄酮的提取工艺改进研究

以广西小叶榕叶为原材料,改进了传统的乙醇热回流提取工艺.用陶瓷复合膜设备和石油醚除去其中的大分子、脂溶性组分和叶绿素,并用单因素实验法对影响总黄酮提取率的主要因素进行了分析,并用正交实验优化了提取总黄酮的最佳工艺条件.研究表明,小叶榕叶提取黄酮类成分的最佳条件为:乙醇浓度60%,提取温度70℃,料液比1:10,提取时间3h,提取3次.通过提取工艺的改进,在最佳条件下总黄酮的提取率从3.38%增加到4.12%,提高了21.89%.     

索骨丹中黄酮和多糖的提取工艺优化研究

目的 研究超声法提取索骨丹中黄酮及多糖的最佳提取工艺.方法 通过单因素实验和正交实验,测定黄酮和多糖的提取率,分析料液比(g·mL-1)、超声时间、乙醇体积分数、提取次数对索骨丹中黄酮提取率的影响;料液比、超声时间、提取次数对索骨丹中多糖提取率的影响,优选了索骨丹中黄酮和多糖超声提取的最佳工艺条件.结果 索骨丹中黄酮的超声提取最佳工艺条件为:提取3次、料液比1:20、乙醇体积分数70％、提取时间40 min,提取率为9.85％;多糖的最佳提取工艺为:提取3次、料液比1:40、提取时间40 min,提取率为1.69％.结论 本实验对索骨丹中黄酮及多糖的超声提取工艺进行了优化,为索骨丹药材的质量控制和有效成分的开发利用提供实验参考.     

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。     

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.     

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.