N-羟基琥珀酰亚胺生物素酯的制备及其热稳定性研究

目的研究N-羟基琥珀酰亚胺生物素酯(BNHS)的制备及其稳定性研究。方法以D-(+)-生物素为原料,与N-羟基琥珀酰亚胺在N,N'-二环己基碳二亚胺作用下反应生成N-羟基琥珀酰亚胺生物素酯,用差示扫描量热法和热重分析研究分析N-羟基琥珀酰亚胺生物素酯的热稳定性和热分解过程。结果合成工艺的收率为79.7%以生物素计。在氮气氛(氮气流量为20 mL·min~(-1))、10 K·min~(-1)的升温条件下,N-羟基琥珀酰亚胺生物素酯在353℃发生剧烈分解,至500℃几乎分解完全。结论所用制备方法简单、产率良好,适合大量制备,且产物热稳定性好。     

N-羟基琥珀酰亚胺生物素酯的合成与应用

利用两种方法合成了N-羟基琥珀酰亚胺生物素酯，并用核磁共振谱进行了结构表征，N-羟基琥珀酰亚胺生物素酯的应用前景非常广泛。     

3-碘-6-卤代咪唑并[1,2-a]吡啶-8-甲酸酯的合成

标题化合物是一类重要杂环化合物,具有较高的生物活性,广泛应用于抗肿瘤药物、抗菌、抗病毒等药物的生产。以2-氨基烟酸为起始原料,经过浓硫酸催化与醇类生成2-氨基烟酸酯,再与N-卤代丁二酰亚胺反应制备2-氨基-5-卤代烟酸酯,再与氯乙醛成环缩合生成6-卤代咪唑并[1,2-a]吡啶-8-甲酸酯,最后和N-碘代琥珀酰亚胺发生碘代反应,共4步制得标题化合物,总收率为58.9%~67.7%。产物结构经IR、1HNMR、13CNMR、元素分析进行了表征。合成路线方法新颖、操作简单、产率高、避免柱层析分离纯化,更适合工业化放大生产。     

生物素标记的Tn抗原的合成

以全乙酰化的2-叠氮基半乳糖基三氯乙酰亚胺酯为起始原料,通过与L-苏氨酸衍生物的糖基化反应以及叠氮还原,并同时进行N-乙酰化的一锅法反应制得全保护的Tn抗原,在脱去苏氨酸上的氨基保护基后,含生物素的琥珀酰亚胺酯与Tn抗原上的氨基发生选择性胺解得到标题化合物.目标产物及重要中间体的结构都通过 1HNMR、13CNMR和MS进行了表征.     

四臂星型生物素化聚乙二醇-聚丙交酯的合成与性能研究

以季戊四醇(PET)为引发剂,在辛酸亚锡催化下,丙交酯(LA)开环聚合合成了四臂星型聚丙交酯(PETPLA4),对其分子链末端羟基进行羧基化后与聚乙二醇(PEG)反应合成了四臂星型聚丙交酯-聚乙二醇[PET-(PLAPEG)4]。N-羟基琥珀酰亚胺与生物素反应合成了琥珀酰亚胺生物素酯(Biotin-NHS),与PET-(PLA-PEG)4反应合成了四臂星型生物素化聚乙二醇-聚丙交酯[PET-(PLA-PEG-biotin)4]。通过核磁和凝胶渗透色谱对其化学结构和分子量进行了表征,通过示差扫描量热仪及界面张力仪对其热性能和亲水性进行了测定。结果表明,此聚合物结构明确,分子量分布较窄,其热性能与聚丙交酯明显不同,其亲水性相对于聚丙交酯有明显改善。     

N-12-羟基硬脂酰氨基酸型表面活性剂的合成与表征

以12-羟基硬脂酸和3种不同类型的天然氨基酸为原料,采用N,N′-二环己基碳酰亚胺(DCC)和N-羟基丁二酰亚胺(NHS)作为偶合剂,合成了3种具有代表性的N-12-羟基硬脂酰氨基酸(酸性、中性和碱性)表面活性剂。首先,12-羟基硬脂酸和N-羟基丁二酰亚胺反应制得N-羟基琥珀酰亚胺12-羟基硬脂酸酯(产率85%以上),然后将后者与氨基酸进行缩合反应得到了N-12-羟基硬脂酰氨基酸表面活性剂。其较佳合成工艺条件为:N-羟基琥珀酰亚胺12-羟基硬脂酸酯与氨基酸摩尔比为1∶1,室温反应,反应时间不少于4 h,以丙酮与水体积比1∶1为混合溶剂,产率达到80%。利用IR、元素分析和1HNMR对所得产物进行表征,确定了产物结构。     

对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯的合成工艺研究

采用N,N-二甲基-2-氯乙酰胺、4-羟基苯乙酸、三乙胺等为原料,于乙腈中反应,HPLC跟踪检测合成对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯(简称化合物B)。结果表明,最佳合成工艺参数为:反应时间12 h,反应温度60℃,溶剂用量为2 200 m L,物料比为n(4-羟基苯乙酸)∶n(N,N-二甲基-2-氯乙酰胺)=1∶1.10。在最佳条件下,收率86%,纯度98%以上。     

顺式那格列奈的合成

首次报道了抗糖尿病新药那格列奈异构体-顺式那格列奈的合成方法。实验中将4-异丙基苯甲酸溶于醋酸中,在催化剂作用下氢化得4-异丙基环己甲酸的顺反异构体混合物,经过硫脲及N-羟基琥珀酰亚胺处理而得顺式4-异丙基环己甲酸琥珀酯,再与D-苯丙氨酸甲酯盐酸盐反应,然后于碱性条件下水解得到顺式那格列奈.以起始原料4-异丙基苯甲酸计,顺式顺式那格列奈纯度为98.8%,总收率为7.63%。     

9-芴甲氧羰基氨基保护试剂的合成与分析

研究了9 芴甲基氯甲酸酯(Fmoc Cl)、9 芴甲基叠氮甲酸酯(Fmoc N3)和9 芴甲基琥珀酰亚胺碳酸酯(Fmoc OSu)这3种氨基保护试剂的合成方法。用碳酸二(三氯甲酯)代替光气与芴甲醇反应得到Fmoc Cl;Fmoc Cl可分别与叠氮化钠及N 羟基琥珀酰亚胺反应得到9 芴甲基叠氮甲酸酯(Fmoc N3)以及9 芴甲基琥珀酰亚胺碳酸酯(Fmoc OSu),收率分别为87 9%和86 9%。上述Fmoc保护试剂在碱性条件下分别与甘氨酸反应进行氨基保护得到产品Fmoc 甘氨酸,收率分别为83 1%、73 3%及93 9%,用毛细管电泳仪分析其摩尔分数分别为97 7%、99 5%及大于99 9%,结果表明,Fmoc OSu是甘氨酸Fmoc氨基保护的最佳试剂。     

2-氯苄基-N-琥珀酰亚胺基碳酸酯的合成研究

以2-氯苄醇和三氯甲基碳酸双酯为起始原料,以二氯乙烷为溶剂,合成了氯甲酸2-氯苄酯,并和N-羟基琥珀酰亚胺反应制备得到肽类保护剂2-氯苄基-N-琥珀酰亚胺基碳酸酯。对反应条件进行了优化,两步反应的总收率接近50%,所得产品经1H NMR确证。     

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。