欧芹酚甲醚肟酯类化合物的制备及其抗乙酰胆碱酯酶活性研究

为研发具有AChE双位点抑制的新型乙酰胆碱酯酶抑制剂,本论文以香豆素类化合物欧芹酚甲醚为先导化合物,通过氧化、还原、酯化等反应设计合成了14个欧芹酚甲醚肟酯衍生物,并经核磁共振波谱(NMR)和质谱(MS)进行结构确证。采用Ellman法测定了目标化合物在1μmol·mL^-1下对乙酰胆碱酯酶的抑制活性,结果显示目标化合物4i和4n对乙酰胆碱酯酶的抑制率分别达到61.6%和51.2%,且与化合物浓度呈正相关。分子对接分析表明化合物4i可以和AChE的催化位点和外周阴离子位点结合。     

7-二乙氨基香豆素腙及酰腙衍生物的制备及乙酰胆碱酯酶抑制活性研究

本论文采用亚活性结构拼接的方法,以7-N,N-二乙氨基-4-甲基香豆素为原料,经二氧化硒氧化,然后与取代肼和取代酰肼反应,合成了13个7-N,N-二乙氨基香豆素腙及酰腙衍生物。所有目标化合物经1H NMR和MS进行结构确证。体外抑制乙酰胆碱酯酶活性结果表明,目标化合物4a和4c对乙酰胆碱酯酶具有较强的抑制活性,其IC50值分别为42. 89和90. 32μmol/L。初步构效关系研究表明,酰腙衍生物对乙酰胆碱酯酶的抑制活性比腙类衍生物好。     

1,3,5-三嗪-喹啉衍生物的合成与生物学活性研究

设计并合成了4个新的1,3,5-三嗪-喹啉衍生物,并研究这些化合物的胆碱酯酶抑制活性。1,3,5-三嗪-喹啉衍生物的结构通过IR、NMR实验得到证实。利用比色Ellman方法测量合成化合物的胆碱酯酶抑制活性。4个化合物中有3个化合物抑制对乙酰胆碱酯酶具有较好的抑制作用,其中,化合物7-chloro-N-(2-(4-(4-chloro-6-(dibutylamino)-1,3,5-triazin-2-yl)piperazin-1-yl)ethyl)quinolin-4-amine(5d)显示出良好的乙酰胆碱酯酶抑制活性(IC₅₀值为7.74μM)。分子对接显示,化合物5d能与乙酰胆碱酯酶的PAS位点结合。合成的4个化合物对丁酰胆碱酯酶的抑制活性都比较弱,显示出比较好的乙酰胆碱酯酶选择性。     

前胡内酯肟酯衍生物的合成及其抑制乙酰胆碱酯酶活性评价

本文以香豆素类化合物前胡内酯为先导化合物,设计合成了12个前胡内酯肟酯衍生物,所有目标化合物经熔点、~1H NMR和MS进行结构确证。体外抑制乙酰胆碱酯酶(AChE)活性评价结果表明,在1μmol/mL浓度下,目标化合物4a和4k对AChE具有较强的抑制活性,其抑制率分别达到58.05%和66.27%。初步构效关系研究表明,引入吲哚环能提高前胡内酯对AChE的抑制活性。通过分子对接方法考察了化合物4k与AChE结合的模式,发现目标化合物可以和AChE的催化活性中心部位结合。     

6-(烷胺酰肼基)-1-氮杂苯并蒽酮衍生物的合成及生物活性研究

以对氯苯乙胺和邻苯二甲酸酐为原料,设计合成了一系列新的6位取代的1-氮杂苯并蒽酮衍生物.并对所合成衍生物的抑制乙酰胆碱酯酶、丁酰胆碱酯酶和乙酰胆碱酯酶诱导的Aβ聚集活性进行了评价.合成的衍生物表现出中等的胆碱酯酶抑制活性,大部分化合物的抑制IC50值处于微摩尔浓度水平.动力学研究表明,衍生物对乙酰胆碱酯酶的抑制类型属于非竞争性抑制.所有化合物表现出有意义的乙酰胆碱酯酶诱导的Aβ聚集抑制活性,其抑制率在35.2%~62.2%之间.而且,合成的18个新衍生物中有11个化合物能够透过血脑屏障进入中枢神经系统.     

3-苯甲酰基香显素类化合物的合成及胆碱酯酶抑制活性研究

以2,4,6-三甲基苯甲酰氯为原料合成2,4,6-三甲基苯甲酰乙酸乙酯2a.以水杨醛类化合物与苯甲酰乙酸乙酯类化合物,六氢吡啶为催化剂在乙醇中发生环合反应,合成了8个3-苯甲酰基类化合物4a-4h,所有的化合物只需要重结晶纯化,就能得到纯度较高的目标产物.所有目标化合物均经过~(13)C NMR,~(1 )H NMR,ESI-MS对其进行了结构确认.在412 nm处,通过紫外分光光度测定化合物对乙酰胆碱酯酶和丁酰胆碱酯酶的抑制活性.     

丹皮酚苯磺酰腙类衍生物的合成及杀粘虫活性研究

丹皮酚可作用于乙酰胆碱酯酶、穿过血脑屏障,该作用机理为使其可能开发成为新型杀虫剂。鉴于此,本文合成了5个丹皮酚苯磺酰腙类衍生物(5a～5e),并评价了它们对威胁农作物的害虫的杀虫活性。在1mg/mL浓度下,以川楝素为阳性对照,采用小叶碟添加法测定化合物3和5a～5e的杀粘虫活性。其中,化合物5e杀虫活性显著,最终校正死亡率(FMR=50.0%)与商品化植物源杀虫剂川楝素等同。初步构效关系研究表明,丹皮酚羰基位修饰是可行的;中间体3的亚胺位磺化修饰可提高杀虫活性,且磺化取代基不同活性差异显著。此外,实验还发现试虫取食了附有供试化合物的叶片后在幼虫期、化蛹期和羽化期均出现不同程度、不同状况的非正常生长。     

基于咔唑的单-/双-硫代碳酰腙衍生物的合成及Cdc25B/PTP1B抑制活性评价

合成了一系列新型的基于咔唑的单-/双-硫代碳酰腙衍生物.利用IR、1H NMR、13C NMR和元素分析对其进行了结构表征.评价了目标化合物对Cdc25B和PTP1B的抑制活性,讨论了其结构与活性的关系.实验结果显示,大部分目标化合物对Cdc25B和PTP1B表现出良好的抑制活性.其中,1,5-双[(9-戊基-3-咔唑基)亚甲基]硫代碳酰腙(4d)对Cdc25B的抑制活性最高,IC50为(0.23±0.02)μg/m L.1,5-双[(9-乙基-3-咔唑基)亚甲基]硫代碳酰腙(4a)对PTP1B的抑制活性最高, IC50为(1.00±0.16)μg/m L.对目标化合物4a和4d进行分子对接研究和密度泛函理论(DFT)计算,结果表明,目标化合物4d和4a分别进入到了Cdc25B和PTP1B酶的活性位点区域,有活性作用的主要是硫代碳酰腙和咔唑基团.     

含1,3,4-噁二唑的喹啉衍生物的合成、抗AChE活性及分子对接研究

为研发新型乙酰胆碱酯酶抑制剂,本文通过碘介导环化反应合成了一系列含1,3,4-噁二唑的喹啉衍生物,并通过熔点和核磁共振确定了其结构。在1 μmol/mL浓度下,对这些衍生物抗乙酰胆碱酯酶活性进行了初步的生物测定。结果表明,化合物4b和4j具有中等的抑制活性,抑制率分别为79.18%和78.46%。初步的构效关系表明,在目标化合物的1,3,4-噁二唑环上引入杂环可以其提高其活性。分子对接研究表明,化合物4b和4j和乙酰胆碱酯酶的催化活性中心部位显著结合。     

高效液相色谱-串联质谱法测定食品添加剂中蛇床子素含量

蛇床子素(osthole)又名甲氧基欧芹酚或欧芹酚甲醚,其化学名称为7-甲氧基-8-异戊烯基香豆素,是最先从伞形科植物中提取分离出的天然香豆素类化合物[1].     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.