乌蕨的化学成分及活性研究进展

乌蕨为鳞始蕨科乌蕨属植物,是一种民间中草药。现代研究表明乌蕨含有黄酮、酚类、挥发油、甾体和多糖等成分,其提取物或单体化合物具有较强的抗菌、抗氧化、抗炎、保肝、止血、解毒等作用。为促进进一步研究,本文对乌蕨的化学成分及活性研究进展进行综述。     

刺头复叶耳蕨的紫外-可见吸收光谱特征研究

目的:以刺头复叶耳蕨不同萃取部位谱线组的特征为依据,较全面地反映刺头复叶耳蕨的内在品质。方法:采用紫外扫描的方式,分别对刺头复叶耳蕨石油醚(60~90℃)、乙酸乙酯、无水乙醇、水萃取部位进行扫描,得到紫外特征曲线。结果:刺头复叶耳蕨4种萃取液均在200~600 nm波长范围内有特征吸收,本测定方法的稳定性、重复性良好,4种萃取液在3 h内稳定性良好,可用于测定刺头复叶耳蕨不同萃取液在紫外-可见光区的吸收特征。结论:刺头复叶耳蕨不同极性溶剂萃取部位的紫外扫描谱线可表达其特征,为采用紫外-可见分光光度法鉴别刺头复叶耳蕨提供基础。     

蟹爪叶盾蕨化学成分预试验

[目的]分析蟹爪叶盾蕨全草的化学成分。[方法]采用经典化学预试法对蟹爪叶盾蕨的水提液、醇提液、石油醚提取液进行化学成分预试。[结果]蟹爪叶盾蕨含有黄酮类、萜类及甾醇类、糖及苷类、酚类、氨基酸、蛋白质、挥发油、内酯、香豆素等类型的化学成分。[结论]该试验为深入研究该植物的成分及活性提供了基础。     

粉背蕨化学成分预试研究

采用经典化学预试法对粉背蕨水提液、醇提液、石油醚提取液进行化学成分预试验。发现粉背蕨含有黄酮类、糖及苷类、酚类、氨基酸、蛋白质、挥发油等化学成分,可能含有皂苷、蒽醌类成分。该试验为深入研究粉背蕨的成分及活性奠定了物质基础。     

披针新月蕨化学成分预试研究

采用经典化学预试法对披针新月蕨水提液、醇提液、石油醚提取液进行化学成分预试验。发现披针新月蕨含有黄酮类、萜类和甾醇、糖及苷类、酚类、氨基酸、蛋白质、挥发油等化学成分。该试验为深入研究披针新月蕨的成分及活性奠定了物质基础。     

溪边凤尾蕨的化学成分预试验研究

目的:初步探索溪边凤尾蕨羽片中可能含有的化学成分。方法:采取试管法、纸色谱法和薄层色谱法,分别对溪边凤尾蕨羽片的石油醚提取液、水提取液、95%乙醇提取液进行研究,通过多种化学试剂的显色反应或沉淀反应,对其可能含有的化学成分进行检测。结果:溪边凤尾蕨羽片可能含有糖及苷类、有机酸类、酚类、甾体类、黄酮类、油脂类、香豆素类、蒽醌类和鞣质类成分。结论:初步得出溪边凤尾蕨羽片含有多种化学成分,为溪边凤尾蕨羽片的提取分离等一系列研究提供了实验基础。     

葫芦茶的研究现状

葫芦茶为豆科葫芦茶属葫芦茶(Tadehagi Triquetrum.),为民间常用中草药,曾收录于1977版药典,具有清热解毒的功效,用于治疗感冒发热、炎症等。目前,对于葫芦茶的研究主要集中在化学成分、药理作用两方面,其中在化学成分方面,迄今已从中分离得到30余个化合物,主要为黄酮类和酚类成分;在药理研究方面,随着研究的深入发现葫芦茶具有抗炎、保肝、抑菌等作用,特别是其改善糖脂代谢的作用引起关注。本文通过查阅文献,总结葫芦茶的化学成分、药理作用研究,以其为该植物的开发利用提供依据。     

阔叶凤尾蕨的化学成分预实验研究

采用经典化学预试法对阔叶凤尾蕨Pteris esquirolii的水提液、醇提液、石油醚提取液中可能存在的化学成分进行初步探索,并结合薄层色谱对其可能含有的化学成分进行初步分析判断和确定。结果显示从阔叶凤尾蕨供试液里检出可能含有酚类、鞣质类、糖类、苷类、黄酮类、有机酸类、甾体类及三萜类等多种化学成分,以期进一步深入研究阔叶凤尾蕨的化学成分及药效物质基础提供了实验依据。     

红豆杉属植物化学成分及其药理作用机制研究进展

以文献调研的方式,查阅了近十年有关红豆杉属植物不同部位提取物的化学成分以及药理作用的文献,并进行归纳总结,尤其是除抗肿瘤活性以外的、研究相对较少的,如可以改善睡眠、稳定血压、利尿的挥发性成分,具抗氧化活性的黄酮类、酚类、生物碱类成分,具有治疗抗阿尔茨海默症能力的金松双黄酮等,对它们的药理作用机制汇总分析。     

壮药肾蕨的生药学研究

目的通过对壮药肾蕨进行整体系统的生药学研究,了解壮药肾蕨各个部位的基本显微结构。初步检测肾蕨的有效活性成分。为肾蕨的药理学研究和药用价值的发掘提供基础数据。方法对肾蕨全草进行组织切片、粉末的显微鉴定,同时根据肾蕨药用部位不同分别进行理化鉴定。结果块茎的横切面类圆型,维管束周韧型。叶柄横切面类似心型,表皮外包被角质层,周韧维管束,木质部U字形。叶下表皮气孔不定式。叶横切面海绵组织和栅栏组织分化不明显。粉末中可见纤维、皮层细胞、具缘纹管胞、叶下表皮细胞、鳞叶表皮细胞、薄壁细胞。理化结果表明肾蕨可能含有还原糖、多糖和苷类、酚类化合物或鞣质、黄酮类、皂苷、强心苷、内脂、香豆素及苷类以及挥发油等化学物质。结论可以为保证肾蕨用药准确和正确鉴定提供参考依据并对该植物的进一步开发利用具有重要意义。     

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。