石松碱的合成方法综述

石松碱是第一个被发现的石松生物碱类化合物, 其较好的生物活性引起了合成工作者的兴趣. 较全面地介绍了石松碱的各种合成路线, 并对其做了简单分析.     

小檗碱衍生物合成及生理活性研究进展

小檗碱是一种季铵型异喹啉生物碱,主要存在于毛茛科、芸香科和小檗科等植物中,具有多种药理功能.近年来,大量小檗碱衍生物的合成,极大提高了小檗碱的生理活性及拓展了小檗碱的应用范围.文章重点综述了小檗碱及其衍生物的生物及化学合成,简述了其生理活性,并对新型小檗碱衍生物合成的设计方向作了展望.     

石杉碱甲类似物的合成及药理研究Ⅰ.(±)-14-氟石杉碱甲

用两种方法合成了(±)-14-氟石杉碱甲(6),并测定了其抑制乙酸胆碱酯酶的生物活性.其抑制活性是(-)-石杉碱甲(1)的1/62.     

白鲜碱的合成

以苯胺为原料经取代、关环、甲基化、还原、消除反应合成了呋喃喹啉类生物碱白鲜碱,总收率17%,其结构经1H NMR,13C NMR和MS确证.     

盐酸黄连碱的全合成

以2,3-二甲氧基苯甲醛为起始原料,经脱甲基、环和、缩和闭环等5步反应合成了盐酸黄连碱,总收率9.9%,其结构经1H NMR和MS表征.     

吴茱萸次碱的合成进展

系统地总结了吴茱萸次碱的合成方法. 根据构建环的种类不同, 把合成方法分为七类, 大部分方法都是以色胺和邻氨基苯甲酸或其衍生物为起始原料, 步骤较长, 适合工业生产的简便、经济适用的方法还有待于进一步研究探索.     

天然产物骆驼宁碱A及其衍生物的合成研究进展

骆驼宁碱A是从骆驼蒿中分离出来的喹唑啉酮类生物碱, 骆驼蒿在中国民间用来治疗风湿病、炎症、脓肿及其他疾病. 由于骆驼宁碱A的药理活性, 有关其合成方法受到了关注. 综述了该化合物的合成方法, 根据闭环方式的不同把合成方法分为六大类, 大部分方法都围绕中间体喹啉吡咯烷酮的合成, 一般步骤较长, 产率过低, 虽然有的路线步骤短, 产率高, 但原料不易得到. 因此, 经济的产业化方法还有待进一步研究.     

TA-EG-GMA合成超支化碱溶性感光聚合物

通过1,2,4-偏苯三酸酐和乙二醇反应合成超支化聚合物,利用合成聚合物分子外围的羧基与甲基丙烯酸缩水甘油酯反应,在超支化聚合物分子外围引入反应性甲基丙烯酰氧基.研究了树脂组成对感光性和碱溶性的影响.结果表明:调整反应物料配比及反应性甲基丙烯酰氧基含量,可以获得较好的碱溶性和光固化性能.     

固体碱催化剂

综述了最近30年来固体碱催化剂的研究现状，包括固体碱催化剂的种类、优缺点以及各类催化剂中影响其催化性能的因素。重点探讨了碱性前驱体和载体对负载型无机固化碱碱强度的影响，展望了未来固体碱剂的发展方向。     

吴茱萸碱的合成及其结构表征和体内抗肿瘤作用

以色胺和N-甲基靛红酸酐作为起始原料合成了吴茱萸碱;利用元素分析仪、红外光谱仪、核磁共振谱仪、质谱仪等对合成产物进行了结构表征,并研究了其对小鼠移植性肉瘤S180和小鼠肝癌H22的体内抗肿瘤作用.结果表明,所合成的吴茱萸碱在高、中、低剂量(20 mg·kg-1、10 mg·kg-1、5 mg·kg-1)下均对S180和...     

Efficient synthesis of piperidine derivatives. Development of metal triflate-catalyzed diastereoselective nucleophilic substitution reactions of 2-methoxy- and 2-acyloxypiperidines.

Nucleophilic substitution reactions of 2-methoxy- and 2-acyloxypiperidines were investigated. First, new and efficient methods for the preparation of the starting piperidine derivatives were developed. N-Benzyloxycarbonyl-2-methoxypiperidine (3) and 3-substituted-2-acyloxy-N-benzyloxycarbonylpiperidines (4a-d), which are recognized as the simplest imino-sugars, were prepared and were examined as substrates for nucleophilic substitution reactions with silyl enolates under the influence of catalytic amounts of metal triflates (Sc(OTf)3, Sn(OTf)2, Cu(OTf)2, Hf(OTf)4, etc). Among the triflates tested, Sc(OTf)3 gave the best results. It was found that 2-acetoxy-3-benzyloxy-N-benzyloxycarbonylpiperidine (4a) reacted with silyl enolates to afford the 2-alkylated adducts in high cis-selectivity, while 2,3-diacyloxy-N-benzyloxycarbonylpiperidines (4b-d) showed transselectivity. The stereochemical assignments were carefully performed using NMR analysis, X-ray crystallography, and synthetic transformations. Febrifugine (1), a potent antimalarial alkaloid, was successfully synthesized from 2,3-diacetoxy-N-benzyloxycarbonylpiperidine (4b) on the basis of these diastereoselective nucleophilic substitution reactions.     

Differentiation of the diastereomeric synthetic precursors of isofebrifugine and febrifugine by electrospray ionization tandem mass spectrometry

Febrifugine is an alkaloid with potent antimalarial activity isolated from Dichroa febrifuga and Hydrangea umbellate, and it exists naturally with its diastereomeric component, isofebrifugine. Here we report the differentiation of diastereomeric synthetic precursors of isofebrifugine (1, cis) and febrifugine (2, trans) and a structurally similar model diastereomeric pair without a halogen substituent (3 and 4) by electrospray ionization (ESI) tandem mass spectrometry. Compounds 1-4 contain a tert-butoxycarbonyl (BOC) substituent, and the collision-induced dissociation (CID) spectra of the [M+H](+), [M+Na](+) and [M+Li](+) ions of 1-4 include the expected product ions corresponding to the loss of C(4)H(8) (isobutene) and of C(5)H(8)O(2) (BOC-H). Loss of C(5)H(8)O(2) is dominant in cis isomers (1 and 3) and/or loss of C(4)H(8) ions is dominant in trans isomers (2 and 4). The decomposition of [M+H](+) ions shows stereoselectivity in the formation of the [M+H-(BOC-H)-C(3)H(5)OBr](+) and [M+H-(BOC-H)-C(6)H(5)CH(2)OH](+) ions. The [M+Cat](+) ions (where Cat = Na or Li) additionally show loss of NaBr and HBr from [M+Cat-(BOC-H)](+), and these product ions are constantly more abundant in cis isomers than in trans isomers. The stereoselectivity for the product ion corresponding to the loss of [(BOC-H)+C(3)H(5)OBr] from [M+H](+) ions differs from that from [M+Cat](+) ions.     

中学化学中的科学方法教育与课程教材改革

本文论述了什么是科学方法;科学方法的特点、性质、类型和结构;为什么要重视科学方法教育;中学化学中应该着重进行哪些科学方法教育;怎样才能有效地进行科学方法教育等问题。指出:科学方法是科学素质的重要构成因素。加强科学方法教育是全面提高学生素质、保证学生可持续发展的需要,也是搞好当前的课程教材改革的需要。文中提出了确定中学化学中科学方法教学内容的原则、各年级教学内容和教学要求的设想,还就科学方法教育的途径和原则提出了自己的看法。作者认为,科学方法教育要力戒教条式灌输,要注意让学生在积累经验基础上进行归纳;重视组织学生参加有关的实践活动;科学方法教育要跟科学精神、科学思想和科学知识的教育相互结合,跟人文精神教育结合。在进行科学方法教育时,还应该重视技术方法教育。     

Multi-component calibration and analysis in liquid chromatography

Multi-wavelength detectors offer improved detection capabilities for liquid chromatographic methods, but require improvements in data analysis methodology to utilize all the available information. In this work, various methods for improving the quantitative results obtained from liquid chromatography with full spectrum fluorescence detection were studied. The availability of multi-wavelenght information allows overlapped chromatographic peaks to be resolved. Different approaches were investigated for developing calibration models that use all of the available spectral information, and are compatible with a variety of methods for quantification, including factor analysis, Kalman filtering and rank annihilation. These methods were compared for their ability to resolve overlapped chromatographic peaks and their accuracy in quantification.     

氰化物分析研究进展

介绍氰化物常用的场外分析和现场检测方法,对实验室(场外)常用分析方法如化学滴定法、分光光度法、色谱法、波谱法等以及现场快速检测方法如目视比色法、分光光度计法等进行了综述,并结合实际需求,总结了不同方法的特点,展望了氰化物检测方法的未来发展趋势。     

Validated green high‐performance liquid chromatographic methods for the determination of coformulated pharmaceuticals: A comparison with reported conventional methods

The introduction of sustainable development concepts to analytical laboratories has recently gained interest, however, most conventional high‐performance liquid chromatography methods do not consider either the effect of the used chemicals or the amount of produced waste on the environment. The aim of this work was to prove that conventional methods can be replaced by greener ones with the same analytical parameters. The suggested methods were designed so that they neither use nor produce harmful chemicals and produce minimum waste to be used in routine analysis without harming the environment. This was achieved by using green mobile phases and short run times. Four mixtures were chosen as models for this study; clidinium bromide/chlordiazepoxide hydrochloride, phenobarbitone/pipenzolate bromide, mebeverine hydrochloride/sulpiride, and chlorphenoxamine hydrochloride/caffeine/8‐chlorotheophylline either in their bulk powder or in their dosage forms. The methods were validated with respect to linearity, precision, accuracy, system suitability, and robustness. The developed methods were compared to the reported conventional high‐performance liquid chromatography methods regarding their greenness profile. The suggested methods were found to be greener and more time‐ and solvent‐saving than the reported ones; hence they can be used for routine analysis of the studied mixtures without harming the environment.     

大气中甲醛及羰基化合物分析研究进展

介绍了国内外大气中的甲醛和羰基化合物分析的进展,展望了其发展的前景。     

稀土硫化物的合成及应用研究进展

稀土硫化物作为环保颜料和热电材料被广泛研究和应用,已成为材料科学领域的研究热点之一。目前主要可通过直接合成法、微波法、还原法这三种方法来合成稀土硫化物。总结了稀土硫化物制备方法的研究进展,讨论了其优缺点。同时讨论了一些稀土硫化物的热电性质和作为颜料的应用。结合本课题组在稀土硫化物方面的研究工作,对稀土硫化物的制备方法和应用的发展方向进行了展望。     

配体-受体相互作用的计算机模拟及其在药物设计中的应用

配体-受体相互作用在许多生物过程中起重要作用, 计算机分子模拟技术和理论化学计算方法在配体-受体相互作用研究中得到了广泛的应用。本文综述了有关配体-受体相互作用分子模拟和理论计算的常用方法及其在药物设计中的应用。