RP-HPLC测定南、北五味子中三种木脂素类成分的含量

采用反相高效液相色谱(RP-HPLC)法检测五味子中三种木脂素类成分的含量。色谱柱为Agilent C18色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇-水(75∶25),流速1.0 m L/min,检测波长250 nm,柱温30℃,进样量10μL。结果表明,3种成分的进样量分别在4~800、4~400、4~400μg/m L范围与各自峰面积积分值呈良好的线性关系(r分别为0.999 3,0.999 8,0.999 9),平均回收率分别为98.44%,98.86%和97.84%,RSD分别为1.24%,1.87%和1.18%(n均为5)。北五味子中五味子醇甲、五味子甲素和五味子乙素含量分别为7.196,1.344,3.476 mg/g,南五味子中不含五味子醇甲,五味子甲素、五味子乙素的含量依次为59.065,3.213 mg/g。该方法快速、准确、重现性好,可用于南、北五味子中木脂素类成分的分析,评价不同来源五味子的质量。     

五味子药材中醇甲和酯甲的测定

五味子以100%甲醇溶解,用超声波清洗器提取20 min,建立一种同时对五味子药材中五味子醇甲和酯甲定性和含量测定的HPLC-MS方法。色谱条件:色谱柱ZORBAXEclipse XDB-C18(150 mm×4.6 mm i.d.,5μm),流动相甲醇-水(体积比65∶35),流速0.8 mL/min,检测波长220 nm,柱温20℃,进样量20μL。质谱条件:电喷雾离子源(ESI+源),扫描范围(m/z):300~600,干燥气温度350℃,干燥气流速8.0 mL/min,雾化气压力275.8 kPa。结果表明,五味子醇甲和酯甲分别在1.3~83.2μg和1.04~66.56μg浓度范围内具有良好的线性关系,相关系数r分别为0.998和0.997,平均加标回收率分别为100.7%和99.7%,RSD均小于2%。本方法灵敏度高、操作简便、结果准确,可用于五味子中五味子醇甲和酯甲定性及定量的测定。     

HPLC法测定舒肝益脾颗粒中五味子甲素的含量

采用高效液相色谱法测定舒肝益脾颗粒中五味子甲素的含量,Agilent—EclipseXDB—C18色谱柱（4．6mm×250mm,5μm）,以乙腈-水进行梯度洗脱,流速1．00mL／min,柱温30℃,检测波长254nm,进样量10μL。结果表明,五味子甲素浓度在0．632—25．28μg/mL范围内与峰面积呈良好的线性关系,r=0．9995;加样平均回收率为99．08％,RSD=0．84％。本方法操作简便,分离效果较好,准确可靠,适用于舒肝益脾颗粒中五味子甲素的含量测定。     

利用HPLC法建立五味子醇甲的检测方法及其方法学考察

[目的]通过高效液相色谱法(HPLC法)建立五味子醇甲的检测方法及其方法学考察。[方法]利用高效液相色谱仪对五味子醇甲进行测定,[结论]本方法操作简单,准确可靠,结果稳定,重复性好,可用来测定五味子醇甲的含量。INERTSLLODS_SP C18(150 mm×4.6 mm,5μm);流动相为甲醇-水(77︰23);流速为1 mL/min;检测波长:254 nm;柱温:30℃;进样量20μL,回归方程为y=38235x+2579.1,R~2=0.9997。[结果]五味子醇甲在6.72~15.12μg/mL范围内,峰面积与进样量呈良好的线性关系。     

HPLC法测定北五味子果实中五味子甲素含量

采用高效液相色谱法,测定了五味子果实中五味子甲素的含量,检测波长为254nm,标准曲线线性关系R2为0．9992,相对标准偏差为0．59％,平均加样回收率为99．16％。结果表明,此方法准确度较高,为五味子生药及成品药中五味子甲素含量测定提供了一种切实可行的方法。     

五味子中木质素类活性成分的高效液相色谱分析

本文建立了五味子药材中五味子醇甲、五味子甲素和五味子乙素含量的测定方法。方法：采用反相高效液相色谱法,使用Kromasil C18柱（250mm×4．6mm,5μm）,以乙腈一水梯度系统为流动相,流速1．0mL·min-1,检测波长218nm。结果：五味子醇甲、五味子甲素、五味子乙素线性范围分别为19．92～398．4、6．24～124．8、12．5～250μg·mL-1,平均回收率分别为99．5％、98．6％、98．5％。结论：本法可用于五味子药材的质量控制。     

五味子药材HPLC指纹图谱的研究

采用HPLC/UV测定五味子药材甲醇提取液的指纹图谱,并对不同产地的五味子的指纹图谱进行比较.色谱条件:ODS色谱柱,甲醇-水线性梯度洗脱,流速1.30 mL·min-1,检测波长220 nm,柱温30℃.结果发现指纹图谱中有22个色谱峰为共有峰,根据其相对保留时间和紫外光谱,确定五味子甲素、五味子乙素、五味子丙素、五味子醇甲、五味子醇乙、五味子酯甲6个成分,并计算了13个样品间相似度.研究证实五味子指纹图谱可用于全面控制五味子药材的质量.     

紫外辐射对五味子叶片中五味子甲素含量的影响

采用UVA、 UVB、 UVC三波段紫外光为五味子新鲜叶片进行辐射,研究波长、辐射时间及样品处理方式对五味子叶片中五味子甲素含量的影响。结果表明紫外辐射提高了五味子甲素的含量,但不同辐射波段对甲素含量增加幅度大小不一。其中以UVB为最佳紫外辐射,五味子甲素含量有明显增加,以6天为宜,含量最高提高了88.2%。     

RP-HPLC测定雷公藤药材中雷公藤甲素

采用反相高效液相色谱法-紫外检测器(RP-HPLC-UV)测定雷公藤药材中雷公藤甲素的含量,色谱柱为Kromasil C18柱(150 mm×4.6 mm,5μm),甲醇∶水溶液(45∶55)为流动相进行等度洗脱,流速1.0 mg/min,进样量20μL,紫外检测波长λ=218 nm。结果表明,每个样本分析时间约10 min,雷公藤甲素保留时间约6.103 min,雷公藤甲素与其他成分分离效果良好,标准曲线y=0.206 7x+2.123 9,r=0.993 3(n=5),线性范围0.01~0.1 mg/m L(r=0.993 3),回收率为96.00%~99.03%,RSD≤2%。本方法专属性强,准确可靠,可以用于雷公藤药材中雷公藤甲素的含量测定。     

五味子化学成分的分离和结构鉴定

目的研究五味子中木脂素类化学成分。方法应用正相硅胶柱色谱、ODS柱色谱、制备型和分析型HPLC及重结晶等方法对五味子提取物的乙酸乙酯部位的化学成分进行了系统研究。结果从五味子乙酸乙酯部位中分离得到了8个化合物,鉴定化合物为五味子醇甲(化合物1)、邻苯二甲酸二丁酯(化合物2)、五味子甲素(化合物3)、柠檬酸双甲酯(化合物4)、柠檬酸单甲酯(化合物5)、五味子酯丙(化合物6)、Schinlignan E(化合物7),当归酰戈米辛H(化合物8)。结论化合物2为首次从本植物中分离得到。     

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.     

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.     

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.     

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。     

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.