超声波提取黄芩药渣中的黄芩苷

为了探索黄芩植物药废渣的再利用价值,首次采用超声波萃取技术对黄芩植物药废渣中的药用有效成分-黄芩苷进行再次提取,考察溶剂浓度、超声提取时间以及溶剂量等因素对黄芩苷提取率的影响。设计正交实验对超声波提取工艺参数进行优化。结果表明超声波最佳提取工艺条件为：15倍量70％浓度的乙醇,在20℃条件下超声提取50min,黄芩苷提取率达6．0％以上。通过试验得出的结论为：黄芩植物药废渣中尚含有一定量的药用有效成分-黄芩苷,具有再资源化利用的价值。     

表面活性剂对黄芩苷微波萃取的影响

研究了表面活性剂对微波萃取黄芩苷的影响,筛选出对微波萃取黄芩苷具有明显协同作用的表面活性剂——单烷基磷酸酯钾盐(MAPK)。通过试验,得到MAPK协同微波萃取黄芩苷的较佳工艺：以质量分数为0．15％的MAPK水溶液为萃取剂,微波300W萃取2次,每次按m(萃取剂)：m(黄芩粉)=10：1加入萃取剂,萃取4min。萃取液用质量分数为15％的HCl调pH=1～2,析出沉淀,过滤,滤饼用水洗和乙醇洗,干燥,即得黄芩苷粗产品,收率为6．8％,黄芩苷质量分数约为88．1％。结果表明：MAPK能降低微波功率,缩短微波辐射时间,并能提高黄芩苷的收率和纯度,对微波萃取黄芩苷具有明显的协同作用。     

黄芩苷在功能性化妆品中的应用研究

简述了黄芩苷用于功能性化妆品的有效性。通过试验，制得了黄芩苷美白霜、黄芩苷抗粉刺嗜喱霜和黄芩苷防晒乳液。按有关标准要求对制得的产品进行了性能测试，并进行了试用效果观察和评价。试用结果为：黄芩苷美白霜总有效率为84．6％，黄芩苷抗粉刺嗜喱霜总有效率为85％。按Q8／T2410—1998测得黄芩苷防晒乳液的吸光度为1．65，具有高效防护紫外线照射效果，适合于户外工作使用。     

高效液相色谱法检测化妆品中黄芩苷、黄芩素和汉黄芩素

建立了高效液相色谱法检测化妆品中黄芩苷、黄芩素和汉黄芩素的方法。样品经磷酸甲醇溶液超声提取,以甲醇-磷酸溶液梯度洗脱和C18反相色谱柱分离,DAD检测器检测计算3种中药成分含量。黄芩苷在0.5~10μg/m L,黄芩素在0.5~10μg/m L及汉黄芩素在0.25~5μg/m L范围内浓度和278 nm紫外光吸收强度呈良好线性关系,相关系数大于0.999,方法检出下限分别为2、2和1 ng,方法回收率95.3%~112.7%,RSD为0.9%~5.2%。该方法适于快速、高效、准确对化妆品中黄芩苷、黄芩素和汉黄芩素进行测定。     

RP-HPLC法测定中成药中黄芩苷的含量

目的：采用高效液相色谱法测定复方鱼腥草片和清热解毒口服液中黄芩苷的含量，以测定其制剂的质量。方法：以C18化学键合硅胶柱分离黄芩苷，以甲醇-水-醋酸（49．5：50：0．5）为流动相，UV检测波长274nm进行测定。结果：理论塔板数以黄芩苷峰计算为2498；平均加样回收率为96．16％，RSD=2．24％（n=6）。黄芩苷的线性范围0.249～2．49μg，对照品浓度与峰面积呈良好的线性关系。结论：该法测定复方鱼腥草片和清热解毒口服液中的黄芩苷含量，快速，重复性好。     

黄芩苷脂质体制备及包封率测定

采用逆相蒸发法,利用卵磷脂制备黄芩苷脂质体,以紫外法测定黄芩苷浓度,透析法测定黄芩苷包封率。结果表明：卵磷脂：胆固醇（m／m）为4：1,有机相：水相为3：1,黄芩苷浓度1．5mg／mL,所制得黄芩苷脂质体粒径均匀、制备量大,包封率达40．4％。     

分子荧光光度法测定黄芩中黄芩苷的含量

采用分子荧光光度法测定黄芩中黄芩苷的含量。结果表明,在硼砂浓度为0.020 moL·L^-1,pH值为12.5,黄芩苷溶液的荧光强度较大。黄芩苷溶液在0.50～2.5μg·mL^-1质量浓度范围内与其荧光强度呈现出良好的线性关系,线性方程为y=176.89+82.14x,R²=0.999 1。根据标准曲线计算得到黄芩药材中黄芩苷的含量。该方法具有选择性好、灵敏度高、操作简单的优点。     

四乙酰野黄芩素的合成

以灯盏花素为原料,在乙二醇-水-盐酸体系中,将原料中的灯盏花乙素水解转化为野黄芩素;中间体野黄芩素在醋酸钾与吡啶的共同催化作用下,经醋酐酰化制得最终产物四乙酰野黄芩素。第一步反应产率为81.3%,所得产物野黄芩素纯度达99.8%;第二步反应产率86.1%,所得产物四乙酰野黄芩素纯度达98.4%。所得产物结构经UV,IR,MS,13CNMR,1HNMR所证实。     

黄芩的生物活性及其在化妆品中的应用

论述了黄芩的资源、主要化学成分、提取方法、生物活性及其在化妆品中的应用等.黄芩中的主要活性成分黄芩苷和黄芩素等具有广泛的生物活性,如抗菌、抗真菌、抗炎、抗过敏、抗氧化、清除自由基、抗紫外线、抗辐射和抑制酪氨酸酶等.可制备防治痤疮、防晒、祛斑美白、抗皮肤老化和防皱等功效性化妆品,防治牙周炎等口腔用品以及外用洗剂等.黄芩素和黄芩苷等黄芩中主要活性成分是集祛斑美白、防晒、抗敏、消炎和抗衰老多效合一的天然高效多功能化妆品添加剂.     

黄芩化学成分和药理作用的研究进展

黄芩(Scutellaria baicalensis)作为中国历史悠久的唇形科草本药用植物,具有多种药理活性,包括抗炎、抗氧化、抗肿瘤、保护神经系统和肝脏等等,回顾近年来对黄岑的一系列实验和临床研究,就黄岑的化学成分和药理作用作一综述。     

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。