纤维素酶法提取玄参总环烯醚萜类成分的工艺优化

为了得到酶解法提取玄参中环烯醚萜类成分最佳提取工艺,通过高效液相色谱法测定环烯醚萜类成分中的哈巴俄苷、哈巴苷和桃叶珊瑚苷的提取率为考察目标,筛选最佳酶种类及用量,并在单因素试验基础上,考察料液比、溶剂pH、酶解温度、提取时间对提取率的影响,再进行正交试验优化,确定最佳提取工艺。实验结果表明,选取0.5%纤维素酶时提取率最高;纤维素酶提取玄参中环烯醚萜类成分最佳提取工艺为:料液比1∶15,溶剂pH=3.5,提取时间2 h,提取温度55℃。在此工艺条件下,环烯醚萜类成分的提取率可达2.254%,比传统热回流提取法可提高30%左右的提取率,比不加酶的条件可提高65%的提取率。     

藕中总黄酮的提取工艺研究

研究了藕中黄酮类化合物的提取工艺。考察了提取温度、提取时间、溶剂浓度、料液比四个单因素对黄酮提取率的影响,根据L9(34)正交试验对黄酮提取条件进行优化。结果表明:该工艺条件下黄酮提取率为:148.606 mg/100 g。最佳提取工艺为:提取温度为70℃,提取时间为60 min,乙醇浓度为70%,料液比为1∶25。     

正交优化提取陈皮中橙皮苷的工艺研究

采用微波辅助提取技术从陈皮中提取橙皮苷,考察了影响橙皮苷提取率的因素,在单因素实验基础上,通过正交试验优化了提取工艺.结果表明,最佳提取工艺条件为:以1.0％氢氧化钠和70％乙醇溶液的混合液为提取溶剂、微波功率200W、微波时间3min、微波温度60℃、料液比1:20(g:mL),在此条件下,提取率可达1.7871％.     

微波法提取红枣中齐墩果酸的工艺条件优化研究

采用微波法提取红枣齐墩果酸,筛选了提取红枣齐墩果酸的理想提取溶剂,通过单因素试验和正交试验考察了乙醇体积分数、液料比、提取温度、微波功率、微波提取时间对齐墩果酸提取率的影响。结果表明,乙醇为提取红枣齐墩果酸的理想提取溶剂;优化的提取工艺参数为:乙醇体积分数为90%、液料比为20∶1、提取温度80℃、微波功率为200 W、微波作用时间120 s,在此工艺条件下,齐墩果酸的提取率为2.4029 mg.g。     

带交互作用的正交试验优选大黄素的提取工艺

对大黄素的超声提取工艺条件进行优化。采用单因素方法考察溶剂种类、提取时间、提取温度、提取次数对大黄素含量及提取率的影响。利用带交互作用的正交试验优化超声提取工艺条件,得到大黄素的最佳超声提取条件为:提取溶剂为含水量5%的乙醇水溶液,提取时间为40min,提取温度为58℃,提取次数为5次。     

胡杨树皮多酚的提取工艺研究

在单因素试验的基础上,采用正交试验,以普鲁士蓝法测定多酚含量为考察指标,探讨了胡杨中植物多酚的提取工艺。由极差分析得知,在本试验所考察的影响因素中,提取时间的影响最大,其次是固液比,溶剂体积分数次之,提取温度对提取率的的影响最小。结果表明:胡杨中植物多酚提取的最佳试验条件为:提取溶剂为40%的丙酮水溶液,固液比为1:7,提取时间为3 h,提取温度为45℃,并结合单因素试验,确定提取次数为3次。在上述条件下,测得胡杨树皮中多酚含量为6.10%,提取率达到99.03%,平均回收率为94.64%。     

正交试验法优化黑龙骨地上茎中总黄酮的提取工艺

目的:优选黑龙骨地上茎中总黄酮的超声提取工艺。方法:以黑龙骨地上茎中总黄酮提取率为指标,采用超声波提取法,利用正交试验法,考察溶剂乙醇浓度、提取时间和料液比三个因素,确定最佳提取工艺。结果:三因素对总黄酮提取率的影响主次顺序为ABC,优选的提取工艺条件是乙醇浓度为50%,料液比为1∶10,超声时间60 min。结论:优选的提取工艺稳定可行,提取率高。     

大飞扬草总三萜提取工艺优化及含量测定

目的:在单因素试验的基础上,通过正交试验优化大飞扬草总三萜的超声提取工艺。方法:以熊果酸标准品为对照,5%香草醛-冰醋酸和高氯酸为显色剂,紫外分光光度法测定大飞扬草中总三萜酸的含量。并在单因素试验的基础上,考察提取溶剂溶度、提取温度、时间及料液比对大飞扬草枝总三萜得率的影响,优化出最佳提取工艺条件。结果:确定三萜的最佳提取工艺为:浓度为80%的乙醇,料液比1︰40,在55℃下,超声提取35 min。结论:优化得到的大飞扬草总三萜酸超声提取工艺稳定,可行。     

响应面法优化超声辅助提取荷叶总生物碱

采用超声辅助从荷叶中提取荷叶总生物碱,采用单因素实验考察了提取溶剂、溶剂pH值、料液比(g∶mL)、溶剂体积分数、提取时间和提取温度对荷叶总生物碱提取率的影响,采用响应面法优化了荷叶总生物碱的提取工艺条件。优化的工艺条件为:溶剂pH值2.0、提取温度70℃、料液比1∶32.1(g∶mL)、乙醇体积分数71.1%、提取时间65.31min,在该条件下,总生物碱的提取率达到5.06%。     

醇水法浸提荔枝草总黄酮的工艺研究

目的:优选醇水溶剂提取荔枝草总黄酮的工艺条件。方法:考察乙醇浓度对提取率的影响,在标准液的制备及标准曲线的制作基础上,选用4个实验因素(浸提温度、乙醇浓度、提取液用量及浸提时间)进行正交实验优选,确定提取荔枝草总黄酮的最佳工艺参数。结果:4种因素对荔枝草中总黄酮提取结果影响依次为:乙醇浓度提取温度提取液用量提取时间,总黄酮提取的最佳工艺条件为:20倍体积的30%乙醇溶液在60℃浸提1 h,总黄酮提取率达4.03%。结论:该实验优选的提取工艺结果重复性好,回收率高,简单可行,为开发荔枝草提供实验依据。     

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。