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1.
以X-5大孔吸附树脂对黑柴胡黄酮粗提液进行分离纯化,测定了黑柴胡黄酮体外抗氧化活性。以静态吸附率和解吸率为指标,确定X-5大孔吸附树脂分离纯化黑柴胡黄酮的最佳工艺为:粗提液中黄酮上样浓度为0.369mg·mL-1、pH值1~2,静态吸附时间7h,45%乙醇或65%乙醇作为解吸剂。纯化后的黑柴胡黄酮具有更好的抗氧化性,其对·DPPH、ABTS+的清除能力及还原力均高于黑柴胡黄酮粗提液。表明X-5大孔吸附树脂是分离纯化黑柴胡黄酮的优良树脂。  相似文献   

2.
本文研究了大孔树脂分离纯化诃子鞣质的方法。先对7种大孔吸附树脂进行静态吸附与解吸性能的考察,进一步对性能相近的HPD600和NKA-9树脂进行动态吸附与洗脱效果比较,选定以NKA-9对诃子鞣质进行分离纯化。优化的工艺条件为:3BV浓度为66.7mg·mL~(-1)的上样液,以1BV·h~(-1)速度通过层析柱,以3BV水洗脱,再以5BV的60%乙醇洗脱,洗脱流速均为3BV·h~(-1)。结果表明,没食子酸和鞣花酸的平均回收率分别为66.05%和84.12%,在干膏中的纯度分别为3.71%和10.38%。经过该工艺纯化后,诃子鞣质得到富集。  相似文献   

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采用静态法从10种大孔树脂中筛选纯化银杏叶黄酮的最佳树脂,并通过动态吸附考察最佳大孔树脂的吸附性能和最优洗脱参数,同时研究银杏叶黄酮提取物对α-葡萄糖苷酶的抑制活性。确定LX-68大孔树脂纯化银杏叶黄酮的最佳工艺条件为:提取液pH值为4.0,上柱流速为2BV·h-1,先以4BV 10%乙醇洗脱杂质,再用70%乙醇洗脱,洗脱流速为3BV·h-1。在此条件下,银杏叶提取物总黄酮含量达27.3%。纯化的银杏叶黄酮提取物具有餐后降血糖的作用,作用优于阿卡波糖,表明银杏叶黄酮提取物是一种优质的降血糖产品。  相似文献   

4.
通过静态吸附解吸实验以及动态吸附解吸实验,优化了AB-8大孔树脂纯化柑橘皮黄酮的工艺。结果表明,AB-8大孔树脂的静态吸附:饱和吸附量15 mg/g(以树脂湿重计),饱和吸附时间180 min,样液最佳p H 5. 5,样液中黄酮浓度高有利于吸附; AB-8大孔树脂的静态解吸液乙醇最佳浓度为80%,黄酮解吸速度很快,少量解吸液可较好地洗脱而得到高浓度黄酮溶液;动态吸附流速3 BV/h,解吸流速6 BV/h,纯化柑橘黄酮的回收率为75. 07%,纯化倍数为4. 14;柑橘皮黄酮主要以糖苷形式存在,苷元较少。  相似文献   

5.
通过静态吸附解吸实验以及动态吸附解吸实验,优化了AB-8大孔树脂纯化柑橘皮黄酮的工艺。结果表明,AB-8大孔树脂的静态吸附:饱和吸附量15 mg/g(以树脂湿重计),饱和吸附时间180 min,样液最佳p H 5. 5,样液中黄酮浓度高有利于吸附; AB-8大孔树脂的静态解吸液乙醇最佳浓度为80%,黄酮解吸速度很快,少量解吸液可较好地洗脱而得到高浓度黄酮溶液;动态吸附流速3 BV/h,解吸流速6 BV/h,纯化柑橘黄酮的回收率为75. 07%,纯化倍数为4. 14;柑橘皮黄酮主要以糖苷形式存在,苷元较少。  相似文献   

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筛选纯化细梗香草总皂苷的最佳大孔树脂,采用单因素试验和正交设计试验优化细梗香草总皂苷的大孔吸附树脂纯化工艺。结果表明,DM130型大孔树脂对细梗香草总皂苷的吸附性能良好,优化后的纯化工艺条件为:上样药液浓度0. 25 g生药·mL~(-1)(p H=8),上样流速4 BV·h~(-1),吸附0. 5 h,依次用蒸馏水、40%乙醇、70%乙醇洗脱4 BV,洗脱流速4 BV·h~(-1)。在此条件下,细梗香草总皂苷的洗脱率达92. 03%,纯度50. 37%。  相似文献   

7.
采用大孔树脂混合使用技术,用于分离纯化竹叶黄酮的工艺研究。通过研究8种大孔树脂对竹叶黄酮的静态吸附与解吸实验,筛选出两种较好的树脂D101-1和AB-8,采用混用技术进行实验,结果表明:D101-1与AB-8的最优混合比例为2:1;上样液质量浓度1.2 mg/m L、上样量为3.5 BV、上样流速2 BV/h为最佳上样条件,洗脱剂体积分数70%、洗脱体积4BV、洗脱流速2 BV/h的条件下进行洗脱。在此条件下进行纯化实验,分离纯化效果最好,样品中黄酮纯度由原来的8.46%上升至28.16%。  相似文献   

8.
比较了大孔树脂吸附与丙酮沉淀法对竹节参总皂苷的纯化效果。结果表明,大孔吸附树脂对竹节参总皂苷具有较好的纯化能力,D101大孔树脂对竹节参总皂苷的吸附能力最佳。最佳洗脱条件为:60%的乙醇洗脱,洗脱剂用量为3BV(BV为树脂体积倍数),洗脱流速为1 mL/min。该条件下竹节参总皂苷纯度可达88.12%(丙酮沉淀法64.30%)。  相似文献   

9.
通过静态吸附及解吸实验,考察5种大孔吸附树脂对杏仁皮单宁的吸附及解吸性能,确定效果最佳的大孔吸附树脂。考察上样浓度、上样流速、上样量对吸附性能的影响,乙醇浓度、洗脱流速、洗脱液用量对解吸性能的影响。结果表明,最佳纯化条件为:采用HP-20型大孔吸附树脂,上样液浓度为1.20 mg/mL,上样流速为1 BV/h,上样量为4 BV,洗脱液为70%乙醇溶液,洗脱液用量为3 BV,洗脱流速为1.5 BV/h。在此条件下,杏仁皮单宁纯度由9.97%提高到32.58%。表明HP-20型大孔吸附树脂纯化杏仁皮单宁工艺可靠、效果良好。  相似文献   

10.
通过静态吸附及解吸实验,考察5种大孔吸附树脂对杏仁皮单宁的吸附及解吸性能,确定效果最佳的大孔吸附树脂。考察上样浓度、上样流速、上样量对吸附性能的影响,乙醇浓度、洗脱流速、洗脱液用量对解吸性能的影响。结果表明,最佳纯化条件为:采用HP-20型大孔吸附树脂,上样液浓度为1.20 mg/mL,上样流速为1 BV/h,上样量为4 BV,洗脱液为70%乙醇溶液,洗脱液用量为3 BV,洗脱流速为1.5 BV/h。在此条件下,杏仁皮单宁纯度由9.97%提高到32.58%。表明HP-20型大孔吸附树脂纯化杏仁皮单宁工艺可靠、效果良好。  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

18.
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.  相似文献   

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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.  相似文献   

20.
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。  相似文献   

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