Microwave-assisted synthesis, anticonvulsant activity and quantum mechanical modelling of N-（4-bromo-3-methylphenyl） semicarbazones

Objective： To study the effect of halo substitution on disubstituted aryl semicarbazones on the anticonvulsant potential and model the activity based on quantum mechanics. Methods： A series of twenty-six compounds of N^4-（4-bromo-3-methylphenyl） semicarbazones were synthesized and evaluated for the anticonvulsant activity in the maximal electroshock seizure （MES） and subcutaneous pentylenetetrazole （scPTZ） seizure threshold tests. Some potential compounds were also tested in the subcutaneous strychnine （scSTY） and subcutaneous picrotoxin （scPIC） seizure threshold tests. The synthesized compounds were tested for behavioral impairment and CNS （central nervous system） depression in mice. Quantum mechanical modelling was carried out on these compounds to gain understanding on the structural features essential for activity. Results： Some compounds possessed broad spectrum anticonvulsant activity as indicated by their effect in pentylenetetrazole, strychnine, picrotoxin and maximal electroshock seizures models in resemblance to other aryl semicarbazone derivatives reported earlier. The higher the difference in HOMO （highest occupied molecular orbital） and LUMO （lowest unoccupied molecular orbital） energy levels was, the greater was the activity profile. Conclusion： The pharmacophoric requirements for compounds to exhibit anticonvulsant activity that includes one aryl unit in proximity to a hydrogen donor-acceptor domain and an electron donor have been justified with the molecular orbital surface analysis of the synthesized compounds.     

金属(Ni、Co、Zn)--Salen配合物的合成及性质研究

本论述了水杨醛与乙二胺，丙二胺，邻苯二胺，对苯二胺合成西佛碱及西佛碱与Co(Ⅱ），Ni(Ⅱ),Zn(Ⅱ)合成Salen金属配合物，这些化合物均被1HNMR，IR和元素分析证实，并讨论它们的电导，紫外，可见光光谱性质。     

Analysis of aroma-active compounds in three sweet osmanthus (Osmanthus fragrans) cultivars by GC-olfactometry and GC-MS

Objective: Aroma is the core factor in aromatherapy. Sensory evaluation of aromas differed among three sweet osmanthus (Osmanthus fragrans) cultivar groups. The purpose of this study was to investigate the aroma-active compounds responsible for these differences. Methods: Gas chromatography-olfactometry (GC-O) and GC-mass spectrometry (GC-MS) were used to analyze the aroma-active compounds and volatiles of creamy-white (’Houban Yingui’, HBYG), yellow (’Liuye Jingui’, LYJG), and orange (’Gecheng Dangui’, GCDG) cultivars. Results: Seventeen aroma-active compounds were detected among 54 volatiles. trans-β-Ocimene, trans-β-ionone, and linalool, which were major volatiles, were identified as aroma-active, while cis-3-hexenyl butanoate, γ-terpinene, and hexyl butanoate were also aroma-active compounds, although their contents were low. Analysis of the odors was based on the sum of the modified frequency (MF) values of aroma-active compounds in different odor groups. HBYG contained more herb odors, contributed by cis-β-ocimene and trans-β-ocimene, while LYJG had more woody/violet/fruity odors released by trans-β-ionone, α-ionone, and hexyl butanoate. In GCDG, the more floral odors were the result of cis-linalool oxide, trans-linalool oxide, and linalool. Conclusions: Aroma-active compounds were not necessarily only the major volatiles: some volatiles with low content also contributed to aroma. The aroma differences among the three cultivars resulted from variation in the content of different odor groups and in the intensities of aroma-active compounds.     

Analysis of volatile organic compounds emitted from aircraft carpets: comparison using headspace and dynamic chamber tests

Volatile organic compounds （VOCs） emitted from three types of carpets used in aircrafts were compared by using headspace and dynamic chamber tests. The headspace samples contained many compounds that were not detected in the dynamic chamber test;in addition, the dominant VOCs found by these two methods were different. The findings indicate that for highly sorptive materials such as carpets, headspace analysis may give inaccurate indication of actual VOC emissions, and it is necessary to conduct dynamic chamber tests over a certain period of time in order to identify the true emission characteristics. From the dynamic chamber tests, 2-ethyl-1-hexanol was the main VOC emitted from all three carpets. The study also examined the emission characteristics of aircraft carpets. In all experiments, total VOC （TVOC） concentration peaked within a few hours after the start of the experiment and was followed by rapid decay. The emission parameters of TVOC emitted by all three carpets were calculated and the simulated data matched the measured data well.     

蒙古语复合词的语法属性描述

笔者以分类法和属性描述的方法,对蒙古语复合词的语法属性进行详细的描述,使复合词的各种语法属性更加具体化、条理化,作为语法属性字段附在每一个词语后面,以便为研制电子版蒙古语复合词语法信息词典提供理论依据。     

熊果酸和齐墩果酸 D-苯甘氨酸缀合物的合成、表征及抗癌活性研究

熊果酸和齐墩果酸为同分异构体,同属五环三萜类化合物,具有多种生物活性,如抗肿瘤、抗HIV、抗炎、降糖、保肝、抗疟等生物活性。本文以具有一定生物活性的熊果酸和齐墩果酸为先导化合物,通过对它们C．28位甲酯化及C．3位导入D-苯甘氨酸,共设计合成了4种未见报道的熊果酸、齐墩果酸衍生物,利用IR和1HNMR波谱技术对其结构进行了表征。然后对目标产物进行了人神经胶质瘤U87AGEFR细胞和人肺癌细胞PC9／G体外抗癌活性测试。结果表明U-3对两种癌细胞的抑制作用明显优于熊果酸和齐墩果酸。     

有机锡氧四元杂环化合物(μ-O)_2Sn_2R_4(R:Me,Et)的理论研究

利用Gaussian03W在LANL2DZ基组水平对有机锡氧四元杂环结构化合物(μ-O)2Sn2R4(R:Me,Et)进行理论研究,优化了几何构型,获得键参数,分析了化合物的Mayer键级,计算出分子体系能、分子最高占据轨道能和分子最低未占据轨道能,经Mulliken布居分析原子净电荷分布,计算出原子轨道对分子轨道的组成贡献。结果表明,除(μ-O)2Sn2Me4外的标题化合物均稳定,为有机锡氧四元杂环化合物(μ-O)2Sn2R4(R!Me)的合成提供理论基础。     

Fascinating organic molecules from nature

Among the several ways of exploiting locally available plants in their day-to-day activities by primitive communities all over the world, catching fish for food was a major one. The plants used for this purpose included species of Derris and Lonchocarpus of the family Leguminosae (Fabaceae). The active principle, rotenone, is a pentacyclic isoflavanoid derivative. Several other closely related compounds are also known and these are together classified as rotenoids.     

Synthesis and Biological Evaluation of Novel N-Benzoxazolonyluracils as Protox-Inhibitor

Protoporphyrinogen oxidase inhibitor has become the focus research field as herbicides.Seven novel N-benzoxazolonyluracils were obtained by cyclization of 6-aminobenzoxazolone derivatives with ethyl 3-dimethylcarbamoylamido-4,4,4-trifluorocrotonate and then methylation or amination, and the reaction yields were between 59%-86%. The chemical structures of the compounds were identified by Elemental Analysis, MS and ^1H NMR. Biological results indicate that some compounds exhibit excellent control of broadleaf weeds at post-emergence by low dosage 18.75 ga.i/ha, but are not effective for grass weeds below dosage 37.5 ga. i/ha. In addition, these compounds show no damage at high-dosage 150 ga. i/ha to wheat and corn, but are unsafe to dicotyledonous plants such as cole, soybean and sorghum even at lower dosage 18.75 ga. i/ha.     

Molecule matters

Divalent carbon compounds which were once considered as highly reactive organic intermediates have been tamed by the modern day synthetic chemist in the form of N-heterocyclic carbenes. The land marks in the history of development of these compounds and their applications as ligands in the Nobel Prize winning work on olefin metathesis catalysts are described. Anil J Elias is a professor at the Department of Chemistry, Indian Institute of Technology, Delhi.     

Fascinating organic molecules from nature

From the very beginning of civilization, humans have used chemicals from Nature ?? most of them comparatively small organic molecules now designated as secondary metabolites ?? for a variety of purposes such as pigments and dyes, arrow and fish poisons and olfactory stimulants. It is no wonder that many eminent chemists were attracted to these materials to elucidate the underlying chemistry. Willstatter, Baeyer, Richard Kuhn, Karrer, Robinson and others made pioneering studies and isolated several new compounds which were included in the curriculum of earlier days. Another pioneer, A G Perkin, second son of Sir W H Perkin, was, according to his elder brother, W H Perkin, Jr, a dabhand with natural dyes.He andAE Everest wrote a book The Natural Organic Colouring Matters, first published in 1918, which was like a Bible to natural product chemists of yesteryears. (You can now read it on line!). As organic chemistry progressed, making leaps and bounds, the newer exciting discoveries gradually pushed the study of several of these compounds out of the curriculum. While one can understand this trend, one also feels sad that students these days are not aware of several interesting facets of natural products chemistry which link organic chemistry with folklore, traditional practices by diverse native communities, indigenous systems of medicine and current ideas of chemical structure and reactivities. It is not possible to fill in these gaps in textbooks which are designed to cater to the needs of students preparing for various university examinations, but articles such as those contemplated here can provide students with knowledge that can be stimulating, interesting as well as enjoyable! We begin the series with ??some exotic red pigments of plant origin??. Several red coloured dyes and pigments of vegetable origin have been known to mankind ever since the dawn of civilization. Their varied uses have been mentioned in ancient literature, including the Ramayana, folklores, travelogues and accounts of several explorers. Their chemistry is equally fascinating and has attracted the attention of a number of eminent organic chemists. In this article, we examine a few of these pigments isolated from plant materials found in different parts of the world. They include the pigments of the red sandalwood, the colourants of safflower, the exotic cosmetic chica red, brazilin from the Brazil wood (and the related hematoxylin), the compounds from the Dragon??s blood, the sesquiterpene quinones of the Miro wood and rottlerin, the main red pigment of Kamala dye.     

新异黏合语的生成机制分析

语义上没有内在联系的两个名词黏合构成的指称形式常常给人以另类新奇的感觉,本文称之为新异黏合语。新异黏合语从本质上看是复合词语,它是基于隐喻或转喻的认知手段而产生的。由于隐喻赖以成立的相似性主要受制于自然因素,转喻赖以成立的相关性除了自然因素之外,还有许多偶发因素的作用,因此,隐喻黏合语是绝对封闭的,而转喻黏合语则是相对开放的。从语义功能上看,隐喻黏合语是一种描写性命名形式,转喻黏合语是一种指示性命名形式。隐喻黏合语易于词汇化,语义解读不必联系特定事件,而转喻黏合语词汇化的概率较低,它的语义解读大多受制于特定事件。文章在分析中还提出了"事件转喻"这一新的认知范畴,并对"语言样板"作了阐释和发挥。     

磺酰胺类化合物的研究进展

磺酰胺类化合物在医药和农药上都具有广泛的生物活性,是近年来药物研究的一个热点。磺酰胺基团引入到各种不同的化合物结构中,通过结构修饰能产生一系列具有广谱生物活性的化合物,这使得它在新药创制中发挥出越来越重要的作用。根据结构的不同进行分类,着重从化学结构、生物活性方面对具有生物活性的磺酰胺类化合物进行综述,并对其发展趋势和应用前景进行了展望。     

偶氮染料废水的处理方法及研究进展

偶氮染料废水是一种有机物含量高、成分复杂、色度高、可生化性差的难降解废水,其处理方法已引起广泛关注。本文阐述了物理法、化学法和生物法3种废水处理方法在偶氮染料废水处理中的应用,并对各种方法进行了评述,展望了今后的发展方向。     

含氮杂环化合物作为农用杀菌剂的开发应用

综述了近年来含氮杂环化合物在农用杀菌剂领域的研究开发情况,介绍了属于含氮杂环化合物的五类最常见的农用杀菌剂.根据这些化合物具有的共性,对含氮杂环类化合物作为农用杀菌剂进一步开发的途径进行了讨论.     

Use of Support Vector Regression Based on Mean Impact Value Model to Identify Active Compounds in a Combination of <Emphasis Type="Italic">Curcuma longa</Emphasis> L. and <Emphasis Type="Italic">Glycyrrhiza</Emphasis> extracts

A support vector regression based on the mean impact value (MIV) model was constructed to identify the bioactive compounds inhibiting proliferation of HeLa cells in a combination of turmeric (Curcuma longa L.) and liquorice (Glycyrrhiza) extracts. The quantitative chemical fingerprint from 50 batches of turmeric and liquorice extracts was established using high performance liquid chromatography hyphenated to an ultraviolet visible detector. Qualitative results were obtained using ultra performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry. A total of 46 peaks (peaks 1–15 from turmeric and 16–46 from liquorice) were selected as “common peaks” for analysis. The inhibitory effect of the combined extracts on HeLa cells was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. It was found that 15 compounds (peaks: 8, 12, 30, 24, 46, 11, 14, 9, 3, 1, 44, 18, 7, 45 and 43) possessing high absolute MIV exhibited a significant correlation with the cytotoxicity against HeLa cells; most of these have already been confirmed with potential cytotoxicity in previous research. The important potential application of the present model can be extended to help discover active compounds from complex herbal medicine prior to traditional bioassay-guided separation. It is considered that this could be a useful tool for re-developing herbal medicine based on the use of these active compounds.     

两个新型4-羟基-3-喹啉羧酸酯类抗球虫化合物的合成

经过亚硝化、催化加氢、缩合、醚化和关环等五步反应,设计并合成了两个新型 4-羟基-3-喹啉羧酸酯类抗球虫化合物．新化合物的合成具有合成路线短、产率高、原料易得、易实现工业化等优点．所有化合物的结构均经1H NMR,IR 和 HRMS 等方法确证．     

Prospective Primary Teachers' Understanding of Climate Change, Greenhouse Effect, and Ozone Layer Depletion

Climate change is one of the most serious global environmental problems and for that reason there has been lately a great interest in educating pupils, the future citizens, about it. Previous research has shown that pupils of all ages and teachers hold many misconceptions and misunderstandings concerning this issue. This paper reports on research concerning student teachers' perceptions about aspects of climate change as well as about greenhouse effect and ozone layer depletion. The aim of this research is to take findings into account for teaching student teachers about these issues. An open-ended questionnaire was used in order to gain a more comprehensive understanding of their thought. From their answers it appeared that these students believe that climate change is under way and base their beliefs on their own experience. They are unaware of the proper actions to be taken for slowing down the climate change, they also hold the misconception that ozone depletion, acid rain, and pollution in general are conducive to climate change. They confuse greenhouse effect with ozone depletion as far as the mechanisms through which they occur is concerned and the causal compounds. By taking into account these research findings the possible implications for teaching are discussed and some suggestions for more effective teaching are made.     

RMn12-xFex(R=Y,Ho,Er)择优占位和晶格振动的原子级模拟

利用基于第一性原理和陈氏晶格反演方法获得的原子间相互作用对势模拟计算了RMn12-xFex（R=Y，Ho，Er）金属间化和物的结构性质，计算结果表明第三组元Fe择优占据8f晶位，8j晶位与8i晶位次之，计算的晶格常数与实验结果符合较好.利用晶格反演的原子间相互作用对势对RMn12-xFex复杂结构的一些力学性质如弹性常数和体模量进行了模拟计算，并首次探讨了该体系的声子态密度曲线及德拜温度.     

计算机语言在化学实验计算中的应用

采用中文环境、菜单项及计算机语言编程进行实验室溶液配制的计算,方便、直观、快速,还能查阅元素原子量和化合物的分子量．以化学实验室常用的６种浓度计算为例说明