3,4-二-o-对甲苯磺酸-D-甘露醇酯的合成及其抑菌活性

以海藻中提取的海洋活性物质D-甘露醇为原料,先与丙酮发生缩合反应,将1,2,5,6位的羟基进行保护,再对3,4位的羟基对甲苯磺酸酯化,最后对异亚丙基进行脱保护,还原1,2,5,6位的羟基。经过三步反应,合成了目标化合物3,4-二-o-对甲苯磺酸-D-甘露醇酯,总产率为42．89％,熔点为76～78℃。合成的中间体和目标产物的结构经红外光谱、元素分析、核磁共振氢谱、碳谱和质谱分析证实与分子式相符。同时首次对其抑茵的生理活性进行了初步研究,结果表明：标题化合物对G^-菌Escherichia coli和G^＋菌Bacillus subtilis具有一定的抑制作用,最小抑制浓度均分别为20g／L和15g／L,而对G^＋菌Staphylococcus aureus基本没有抑制作用。     

1,2,5,6-双异亚丙基-D-甘露醇的合成与表征

以D-甘露醇为起始原料,在氯化亚锡的催化下使用了2,2-二甲氧基丙烷,对1,2以及5,6位羟基进行保护,提高了羟基保护的选择,合成1,2,5,6-双异亚丙基-D-甘露醇。结果表明最佳反应条件为:D-甘露醇与2,2-二甲氧基丙烷摩尔比为1∶3.0,无水氯化亚锡与D-甘露醇摩尔比1∶200,反应时间1h,收率为92.0%。用IR与1HNMR对其结构进行了表征。     

ICIA公司蔗糖水解还原法制山梨醇和甘露醇的生产技术

一、前言 山梨醇和甘露醇是空间异构体,分子式皆为C_6H_(14)O_6。两者都是六元醇,分子中含有六个羟基,既有吸水保湿功能,又可发生醚化、酯化等反应,因而在医药、食品、化妆品和轻化产品等领域获得广泛应用。 山梨醇生产方法按原料路线分有葡萄糖还原法、蔗糖水解还原法等。我国绝大部分厂家采用葡萄糖还原法。甘露醇通常由提取碘后的海带经碱处理后,采用离子交换法制取。蔗糖水解还原法制山梨醇和甘露醇路线国内仍处试验阶段。兹将ICI澳大利亚     

9,10-二羟基环十六内酯的合成

紫胶桐酸是一种具有生物活性的长链羟基烷酸,可用于大环内酯的合成。以紫胶桐酸多羟基作为起始原料,利用高度稀释的合成策略,通过缩醛选择性保护邻二醇、直链前体内酯化环合及酸催化环缩醛脱保护三步反应制备得到了目标产物9,10-二羟基-环十六内酯,总收率为31%,所得产物经红外光谱(IR)、核磁共振氢谱和碳谱(1 H NMR和13C NMR)、电喷雾质谱(ESI-MS)表征得以证实。实验均在室温下进行,反应条件温和,简洁有效。     

甘露醇-硝酸铝溶液燃烧法制备γ-Al_2O_3纳米粉体

以九水硝酸铝,甘露醇和氨水的混合溶液作为前驱体溶液,采用溶液-燃烧法直接焙烧一步合成纳米γ-Al2O3。利用XRD、TEM和N2吸附-脱附等方法对最终形成的氧化铝进行了表征。结果表明,九水硝酸铝与甘露醇物质的量之比为26:15,前驱体溶液的p H值为4,焙烧温度为800℃,焙烧时间为4 h,在此条件下,可制备出蓬松且晶粒尺寸在4~6 nm之间的γ-Al2O3纳米粉体。     

新型肉桂酰胺衍生物的合成及其抑制酪氨酸酶活性的研究

目的:肉桂酰胺类化合物具有抑制酪氨酸酶活性、促进细胞调亡、降低血压、增强免疫、抗氧化等多种生物活性。本文设计合成了一系列肉桂酰胺衍生物,并对其抑制酪氨酸酶活性进行初步的评价。方法:以不同的取代苯甲醛为原料,经过羟基的保护、烯化、水解、缩合等化学反应合成目标产物。以曲酸为阳性对照,评估了合成化合物对酪氨酸酶的抑制活性。结果:合成了10个化合物,其中4个化合物未见相关文献报道,其结构经核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)和质谱(LRMS)等确证。对设计、合成的10个肉桂酰胺衍生物进行了酪氨酸酶的抑制作用的评价,其中2个化合物在25μmol·L-1浓度下具有明显的酪氨酸酶抑制活性。     

3-羟基-1-金刚烷甲酸的合成研究

以1-金刚烷甲酸为原料、硝酸和浓硫酸为氧化剂氧化合成了3-羟基-1-金刚烷甲酸。在优化反应条件下,3-羟基-1-金刚烷甲酸最高收率可达77％。采用红外光谱、核磁共振氢谱、元素分析、熔点测定等方法对产物进行了结构鉴定,并提出了可能的反应机理。     

(25R)-26-羟基胆固醇的合成研究

本研究对(25R)-26-羟基胆固醇的合成路线及方法进行了改进。以薯蓣皂苷元为起始物,经开环反应得到(25R)-3-羟基基胆甾-5-烯-16,26-二醇,再经叔丁基二甲基氯硅烷保护C3-和C26-位羟基后依次经磺酰化、四氢铝锂还原得到(25R)-3,26-二叔丁基二甲硅氧基-5-烯,最后经四丁基氟化铵脱保护得到(25R)-26-羟基胆固醇,总收率54%。改进后路线具有条件温和,分离纯化简便等优点。所合成关键中间体及目标化合物经核磁氢谱、高分辨质谱确证。     

硝酸酯类含能黏合剂绿色合成研究进展

对3种具有发展潜力的硝酸酯类含能黏合剂聚(3-甲基硝酸酯-3-甲基环氧丁烷)(Poly-NIMMO)、聚缩水甘油硝酸酯(PolyGLYN)和硝化端羟基聚丁二烯(NHTPB)的绿色合成工艺和性质进行了简要评述,分析了这些黏合剂的发展前景。并采用以五氧化二氮为硝化剂的绿色合成路线制备得到NHTPB黏合剂,考察了不同官能团对其热稳定性和玻璃化转变温度的影响规律。     

7-硝氧烷氧基-3-乙酰基香豆素的合成及抗血小板聚集活性

以间苯二酚为起始原料,经Vilsmeier-Haack反应、Knoevenagel反应得到7-羟基-3-乙酰基香豆素(3),再利用其7位羟基通过连接臂与有机硝酸酯类NO供体耦合,得到5个7-硝氧烷氧基-3-乙酰基香豆素(5a～5e).目标化合物经过红外光谱(IR)、核磁共振氢谱(1H NMR)和高分辨质谱(HRMS)表...     

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。