ch6-2_eng combinational logic

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酰胺化合物的核磁共振氢谱

大学化学Univ. Chem. 2024, 39 (3), 231收稿：2023-09-05；录用：2023-11-08；网络发表：2023-11-28*通讯作者，Email:******************.cn基金资助：河南省高等学校重点科研项目资助计划(23A150037)；河南省博士后科学基金(202103087)；河南省科技攻关项目(222102310562)•知识介绍• doi: 10.3866/PKU.DXHX202309020 酰胺化合物的核磁共振氢谱吴昊，刘珍，白大昌*河南师范大学化学化工学院，抗病毒性传染病创新药物全国重点实验室，河南新乡 453007摘要：酰胺是一类非常重要的化合物，广泛存在于多肽和生物碱等生物活性分子中，在化工、染料以及药物研发等领域也具有重要的应用价值。

因此，学习酰胺化合物的合成以及结构鉴定具有重要的意义。

由于酰胺化合物的氮原子上的孤对电子能够离域到羰基(C ＝O)上，导致酰胺RCO ―N 上的C ―N 键表现出部分双键性质，C ―N 键不能自由旋转，使得酰胺化合物的核磁共振氢谱较复杂。

本文总结了酰胺的核磁共振氢谱特征，探讨了酰胺异构化的一些影响因素。

通过酰胺核磁共振氢谱的学习，培养学生对核磁共振谱图解析的能力，并加深对酰胺类化合物的理解和认识。

关键词：酰胺化合物；核磁共振氢谱；异构化中图分类号：G64；O61H NMR Spectrum of Amide CompoundsHao Wu, Zhen Liu, Dachang Bai *State Key Laboratory of Antiviral Drugs, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, Henan Province, China.Abstract: Amides are one of the most important classes of compounds that widely exist in bioactive molecules such as peptides and alkaloids. They also have important applications in various fields such as chemical engineering, dyes and pharmaceutical development. Therefore, studying the synthesis and structural identification of amide compounds is of great significance. Due to the delocalization of lone pair electrons from the nitrogen atom of amide compounds to the carbonyl group (C ＝O), the C ―N bond in the amide RCO ―N exhibits partial double bond properties, preventing free rotation and resulting in complex nuclear magnetic resonance hydrogen spectrum (1H NMR). This article summarizes the characteristics of 1H NMR spectra of amides and discusses some factors influencing amide isomerization. This article will cultivate students’ ability to analyze the 1H NMR of amides and deepen their understanding and knowledge of amide compounds.Key Words: Amide compounds; Nuclear magnetic resonance hydrogen spectroscopy; Isomerization酰胺是一类非常重要的有机化合物，是很多天然产物和药物分子的结构单元。

ch6.1

vbe VT β VT = = rπ = ib I BQ I CQ
transconductance g m =
I CQ VT
1. Hybrid-π Equivalent Circuit of BJT
For output loop
iC = iC iB
+
iB
c b T
iC
+
iB
Q
vBE
vCE e
Incremental values can be represented by ac signal
Ch6 Basic BJT Amplifiers 6.1 AC Analysis of Transistor Circuits 6.1.1 Graphical Analysis 6.1.2 Small-Signal Model Analysis 6.1.3 Common-Emitter Amplifiers
C2 +
+ RL vo
Common-Emitter Circuit
Rb may open circuit, IB=0, IC=0, VCE= VCC - IC Rc= VCC . C1 may short circuit VBE=0, IB=0, IC=0, VCE= VCC - IC Rc= VCC . , , ,
6.1.2 Small-Signal Model Analysis
1. Hybrid-π Equivalent Circuit of BJT vbe= ibrπ rπ is base-emitter input resistor. 1/rπ is slope of input curve. From transfer process of carries we know:

甲氧基乙酸甲酯的合成及应用进展

第49卷第10期2021年5月广㊀州㊀化㊀工Guangzhou Chemical Industry Vol.49No.10 May.2021甲氧基乙酸甲酯的合成及应用进展陈春玉,王少楠,胡㊀迎(西南化工研究设计院有限公司,四川㊀成都㊀610225)摘㊀要:甲氧基乙酸甲酯不仅是一种合成维生素B6㊁周效磺胺等药物的重要原材料,而且还是更经济合理合成乙二醇的重要原材料㊂当前制备工艺主要包括甲醛和甲酸甲酯偶联法㊁氯乙酸类和甲醇钠取代法㊁乙二醇单甲醚氧化法和甲缩醛羰基法㊂分析了制备甲氧基乙酸甲酯的方法的优缺点,综述了甲氧基乙酸甲酯在应用领域的研究进展,并对其发展趋势和应用前景作了展望㊂关键词:甲氧基乙酸甲酯;合成;应用㊀中图分类号:O622.5㊀文献标志码:A文章编号:1001-9677(2021)010-0014-02 Synthesis and Application of PolymethylmethacrylateCHEN Chun-yu,WANG Shao-nan,HU Ying(Southwest Research&Design Institute of the Chemical Industry Co.,Ltd.,Sichuan Chengdu610225,China)Abstract:Methyl methoxyacetateis not only an important raw material for vitamin B6,sulfanilamide and other drugs, but also an important even more economical and reasonable raw material for ethylene glycol.Current productions include mainly formaldehyde and methyl formate coupling method,chloroacetic acid and sodium methoxide substitution method, ethylene glycol monomethyl ether oxidation method and methylal carbonyl method.The advantages and disadvantages of eachmethods,the research progress on application of methyl methoxyacetate and the developing trend,as well as prospects for future application of methyl methoxyacetate,were presented.Key words:methyl methoxyacetate;synthetic;application甲氧基乙酸甲酯(下简称MMAc)是一种非常重要的精细化学品,具有酯的性质,常用于水解反应或加成反应,应用面广,比如:是手性胺类化合物的拆分剂,也是多种化工产品的中间体,同时在医药方面也具有很大用途,例如合成维生素B6㊁周效磺胺等药物;此外它也是高效合成下游产品乙二醇重要的前驱体原料㊂1㊀MMAc的合成方法MMAc的合成方法比较多,按照原料划分,有甲醛和甲酸甲酯偶联法㊁氯乙酸类和甲醇钠取代法㊁乙二醇单甲醚氧化法和甲缩醛羰基法等㊂(1)甲醛和甲酸甲酯偶联法甲醛和甲酸甲酯在酸催化剂条件下反应生成MMAc,此法分三步进行,第一步是甲酸甲酯在酸催化剂条件下分解成甲醇和一氧化碳;第二步是甲醇在酸催化剂条件下,醇羟基与氢离子结合生成佯盐的过渡态,甲醛在酸催化剂条件下,醛基与氢离子结合形成质子化的过渡态;第三步是两种过渡态分别与CO结合,发生羰基化反应,最终生成目标产物㊂基于此合成机理,2006年,王克冰等[1]报道了以三聚甲醛和甲酸甲酯为原料,在CF3SO3H酸催化条件下,110ħ反应2h,MMAc的收率为42.72%,由于此反应副产物多,所以收率很低㊂(2)氯乙酸类和甲醇钠取代法氯乙酸类化合物和甲醇钠反应生成MMAc,是卤代烃与醇钠反应制备混合醚的威廉姆逊合成法,反应机理为醇羟基在碱性条件下形成醇负离子,进攻卤代烃的碳正中心,卤代烃脱去卤素形成醚键㊂1989年,中国专利[2]报道了一种制备甲氧基乙酸的方法,采用氯乙酸和甲醇钠为原料,在40ħ条件下反应,得到甲氧基乙酸收率为91%;然后甲氧基乙酸与甲醇酯化后生成MMAc㊂CH3ONa+ClCH2COOHңCH3OCH2COOH+NaCl CH3OOH+CH3OCH2COOHңCH3OCH2COOCH3+H2O 2002年,徐志珍等[3]报道以氯乙酸甲酯和甲醇钠为原料,在80ħ条件下反应4h,合成的MMAc收率为96.2%㊂CH3ONa+ClCH2COOCH3ңCH3OCH2COOCH3+NaCl此法中使用的甲醇钠,价格比较昂贵,而且容易与空气中的水蒸气反应,不易保存,故不是一条经济合理的工业化合成路线㊂(3)乙二醇单甲醚氧化法以乙二醇单甲醚为原料合成MMAc,分两步完成,第一步是乙二醇单甲醚氧化生成甲氧基乙酸,第二步是甲氧基乙酸与甲醇发生酯化反应,生成目标产物㊂第49卷第10期陈春玉,等:甲氧基乙酸甲酯的合成及应用进展15㊀2015年,中国专利[4]报道以Pt/C为催化剂,O2为氧化剂,水为溶剂,在70ħ下反应7h,则乙二醇单甲醚氧化制得甲氧基乙酸,收率为91%;然后甲氧基乙酸再与甲醇酯化,生成MMAc㊂3CH3CO(CH2)2OH+3O2ң4CH3OCH2COOHCH3OCH2COOH+CH2OHңCH3OCH2COOCH3+H2O此氧化法中虽然反应收率较高,但是反应中使用了贵金属,成本高,同时反应时间较长,不是一条合适的工业化路线㊂(4)甲缩醛羰基法甲缩醛羰基法是迄今为止研究的最多的制备MMAc的方法㊂以甲缩醛为原料合成MMAc,是一种Koch型机理,即CO 与酸中氢正离子结合后,进攻甲缩醛中的仲碳,使仲碳失去氢正离子后,完成在仲碳上的插入CO的羰基化反应㊂3CH3OCH2OCH3+COңCH3OCH2COOCH3+2CH3OCH3+HCOOCH3 2015年,中国专利[5]报道在一价铜改性的磺酸型聚苯乙烯交联树脂催化剂条件下,甲缩醛与CO在120ħ下发生羰基化反应,生成最终产物MMAc,反应收率为87%左右㊂2016年,中国专利[6]报道在固体酸催化剂和多聚甲醛的条件下,110ħ反应6h,含水甲缩醛(含水量2%)与CO生成主产物MMAc,反应收率为72%左右㊂2020年,张晓艳[7]报道以ZSM-5分子筛为催化剂,110ħ下反应7h,甲缩醛和CO生成的MMAc收率为69%左右㊂甲缩醛简单易得且价格便宜,是合成MMAc的最佳原料,但是由于甲缩醛易发生歧化反应,副产物较多,只有通过研究不同催化剂来提高MMAc的选择性,才能走出一条清洁生产㊁经济合理的工业化路线㊂综上所述,尽管合成MMAc的路线很多,但由于反应条件苛刻,反应过程复杂,副产物比较多,收率比较低,所用催化剂难回收,分离成本高,易腐蚀设备,耗能高,污染环境,不利于工业化高质量生产㊂故迫切需要找出一种低能耗㊁高效率㊁低污染的生产MMAc的方法㊂2㊀MMAc的应用研究MMAc是一种重要的医药中间体和精细化工产品中间体,能在一定条件下转化为其衍生物维生素B6㊁周效磺胺以及乙二醇等药物或化工产品,具有广泛的用途㊂(1)医药领域MMAc经取代㊁环化等过程可以合成维生素B6,该方法是1939年Harris S A等[8]开发的,简称吡啶酮法㊂维生素B6是人体必需的维生素之一,是人体内约140种酶的辅酶,参与催化80多种生化反应,是人体内许多代谢反应不可或缺的指挥者,还可以预防妇产科疾病以及在保健方面也有一定的作用,所以MMAc在制备维生素B6过程中有着悠久的历史㊂另外,由MMAc经克氏反应㊁酰胺化环合反应㊁氯化反应㊁缩合反应㊁甲氧基化反应合成周效磺胺㊂周效磺胺治疗各种细菌感染,特别适用于皮肤感染㊁肺及上呼吸道感染㊁细菌性痢疾,还治疗疟疾㊁麻疯病,与异烟肼合用治疗肺结核[9]㊂由此可见,MMAc在制备周效磺胺过程中发挥着重要作用,相信在不久的将来,越来越多的以MMAc为原料的药物将会被合成㊂(2)化工领域MMAc除了可以合成维生素B6㊁合成周效磺胺外,更多的使用价值是作为乙二醇的前体,即MMAc通过加氢㊁水解两步高效制成乙二醇㊂乙二醇是国家重要的化工原料和战略物资,可用作溶剂㊁防冻剂以及合成涤纶的原料㊂在溶剂方面,乙二醇常可代替甘油使用,在制革和制药工业中分别用作水合剂和溶剂,也可用于玻璃纸㊁纤维㊁皮革㊁粘合剂的湿润剂㊂在防冻剂方面,乙二醇60%的水溶液凝固点为-40ħ,可用作冬季汽车散热器的防冻剂和飞机发动机的致冷剂㊂乙二醇也是合成聚酯涤纶㊁纤维和化妆品的原料㊂乙二醇的高聚物聚乙二醇(PEG)是一种相转移催化剂,用于细胞融合;乙二醇的硝酸酯是一种炸药,因此,MMAc作为合成下游产品乙二醇的应用前景十分广阔㊂3㊀结㊀语通过对MMAc的合成方向及应用方面的介绍,可以看出,虽然MMAc在国内外研究较多,但是至今在工业化生产道路上还是存在,如何提高其反应收率,降低生产成本,减少环境污染等问题㊂尤其是在廉价的甲缩醛法越来越显现出其特有的优越性的条件下,但是甲缩醛法的研究工作仍然进展缓慢,且不是很理想㊂一方面,甲缩醛容易发生歧化反应,使得反应副产物多,后处理困难,不利于环保要求,如何尽可能多的得到目标产物MMAc,以此提高反应收率也是迫切需要解决的问题;另一方面,甲缩醛的羰基化反应受酸强度的影响非常大,较强的酸具有较强的催化活性,但是强酸对设备腐蚀严重,所以就需要通过寻找合适的催化剂或助催化剂来解决,还需要通过探索最佳化学计量比㊁改变反应时间或温度来提高反应的收率与纯度,以此取得较好的效果㊂因此,发展高效㊁温和的催化体系,实现生产成本低,环境污染小,适合于MMAc的工业化生产路线无论从经济利益还是环境影响两个方面,都具有重要意义㊂总之,随着科技的进步,MMAc的应用领域会越来越广,因此对其合成方向及应用领域的深入开发和研究还是十分有价值的㊂参考文献[1]㊀王克冰,姚洁,王越,等.酸催化剂在甲醛与甲酸甲酯偶联反应中的作用研究[J].天然气化工2006,31(6):19-21.[2]㊀奥戈奇㊃巴尔,瑞奇㊃劳尤什,佩伊瓦㊃耶诺,等.甲氧基乙酸的制备方法[P].中国:1039798A.1989-07-14.[3]㊀徐志珍,潘鹤林.甲氧基乙酸甲酯合成工艺研究[J].上海化工,2002,27(7):14-15.[4]㊀聂俊琦,李雄,王亦鸣,等.一种甲氧基乙酸的制备方法[P].中国:104892390A.2015-04-17.[5]㊀李晓明,吕建刚,刘波,等.甲氧基乙酸甲酯催化剂[P].中国:106582833A.2015-10-14.[6]㊀石磊,龚页境,王玉鑫.利用工业含水原料甲缩醛制备甲氧基乙酸甲酯的方法[P].中国:106518676A.2016-09-05.[7]㊀张晓艳.ZSM-5分子筛催化甲缩醛气相羰基化制备甲氧基乙酸甲酯研究[D].太原:山西大学化学化工学院,2020.[8]㊀Harris S A,Folkers K.Synthesis of vitamin B6[J].J.Am.Chem.Soc.,1939,61:1245-1247.[9]㊀上海化学工业设计院.周效磺胺设计简介[J].医药农药工业设计,1972(4):1-7.。

大环多胺

New1H-Pyrazole-Containing Polyamine Receptors Able ToComplex L-Glutamate in Water at Physiological pH ValuesCarlos Miranda,†Francisco Escartı´,‡Laurent Lamarque,†Marı´a J.R.Yunta,§Pilar Navarro,*,†Enrique Garcı´a-Espan˜a,*,‡and M.Luisa Jimeno†Contribution from the Instituto de Quı´mica Me´dica,Centro de Quı´mica Orga´nica Manuel Lora Tamayo,CSIC,C/Juan de la Cier V a3,28006Madrid,Spain,Departamento de Quı´mica Inorga´nica,Facultad de Quı´mica,Uni V ersidad de Valencia,c/Doctor Moliner50, 46100Burjassot(Valencia),Spain,and Departamento de Quı´mica Orga´nica,Facultad deQuı´mica,Uni V ersidad Complutense de Madrid,A V plutense s/n,28040Madrid,SpainReceived April16,2003;E-mail:enrique.garcia-es@uv.esAbstract:The interaction of the pyrazole-containing macrocyclic receptors3,6,9,12,13,16,19,22,25,26-decaazatricyclo-[22.2.1.111,14]-octacosa-1(27),11,14(28),24-tetraene1[L1],13,26-dibenzyl-3,6,9,12,13,16,-19,22,25,26-decaazatricyclo-[22.2.1.111,14]-octacosa-1(27),11,14(28),24-tetraene2[L2],3,9,12,13,16,22,-25,26-octaazatricyclo-[22.2.1.111,14]-octacosa-1(27),11,14(28),24-tetraene3[L3],6,19-dibenzyl-3,6,9,12,13,-16,19,22,25,26-decaazatricyclo-[22.2.1.111,14]-octacosa-1(27),11,14(28),24-tetraene4[L4],6,19-diphenethyl-3,6,9,12,13,16,19,22,25,26-decaazatricyclo-[22.2.1.111,14]-octacosa-1(27),11,14(28),24-tetraene5[L5],and 6,19-dioctyl-3,6,9,12,13,16,19,22,25,26-decaazatricyclo-[22.2.1.111,14]-octacosa-1(27),11,14(28),24-tetra-ene6[L6]with L-glutamate in aqueous solution has been studied by potentiometric techniques.The synthesis of receptors3-6[L3-L6]is described for the first time.The potentiometric results show that4[L4]containing benzyl groups in the central nitrogens of the polyamine side chains is the receptor displaying the larger interaction at pH7.4(K eff)2.04×104).The presence of phenethyl5[L5]or octyl groups6[L6]instead of benzyl groups4[L4]in the central nitrogens of the chains produces a drastic decrease in the stability[K eff )3.51×102(5),K eff)3.64×102(6)].The studies show the relevance of the central polyaminic nitrogen in the interaction with glutamate.1[L1]and2[L2]with secondary nitrogens in this position present significantly larger interactions than3[L3],which lacks an amino group in the center of the chains.The NMR and modeling studies suggest the important contribution of hydrogen bonding andπ-cation interaction to adduct formation.IntroductionThe search for the L-glutamate receptor field has been andcontinues to be in a state of almost explosive development.1 L-Glutamate(Glu)is thought to be the predominant excitatory transmitter in the central nervous system(CNS)acting at a rangeof excitatory amino acid receptors.It is well-known that it playsa vital role mediating a great part of the synaptic transmission.2However,there is an increasing amount of experimentalevidence that metabolic defects and glutamatergic abnormalitiescan exacerbate or induce glutamate-mediated excitotoxic damageand consequently neurological disorders.3,4Overactivation ofionotropic(NMDA,AMPA,and Kainate)receptors(iGluRs)by Glu yields an excessive Ca2+influx that produces irreversible loss of neurons of specific areas of the brain.5There is much evidence that these processes induce,at least in part,neuro-degenerative illnesses such as Parkinson,Alzheimer,Huntington, AIDS,dementia,and amyotrophic lateral sclerosis(ALS).6In particular,ALS is one of the neurodegenerative disorders for which there is more evidence that excitotoxicity due to an increase in Glu concentration may contribute to the pathology of the disease.7Memantine,a drug able to antagonize the pathological effects of sustained,but relatively small,increases in extracellular glutamate concentration,has been recently received for the treatment of Alzheimer disease.8However,there is not an effective treatment for ALS.Therefore,the preparation of adequately functionalized synthetic receptors for L-glutamate seems to be an important target in finding new routes for controlling abnormal excitatory processes.However,effective recognition in water of aminocarboxylic acids is not an easy task due to its zwitterionic character at physiological pH values and to the strong competition that it finds in its own solvent.9†Centro de Quı´mica Orga´nica Manuel Lora Tamayo.‡Universidad de Valencia.§Universidad Complutense de Madrid.(1)Jane,D.E.In Medicinal Chemistry into the Millenium;Campbell,M.M.,Blagbrough,I.S.,Eds.;Royal Society of Chemistry:Cambridge,2001;pp67-84.(2)(a)Standaert,D.G.;Young,A.B.In The Pharmacological Basis ofTherapeutics;Hardman,J.G.,Goodman Gilman,A.,Limbird,L.E.,Eds.;McGraw-Hill:New York,1996;Chapter22,p503.(b)Fletcher,E.J.;Loge,D.In An Introduction to Neurotransmission in Health and Disease;Riederer,P.,Kopp,N.,Pearson,J.,Eds.;Oxford University Press:New York,1990;Chapter7,p79.(3)Michaelis,E.K.Prog.Neurobiol.1998,54,369-415.(4)Olney,J.W.Science1969,164,719-721.(5)Green,J.G.;Greenamyre,J.T.Prog.Neurobiol.1996,48,613-63.(6)Bra¨un-Osborne,H.;Egebjerg,J.;Nielsen,E.O.;Madsen,U.;Krogsgaard-Larsen,P.J.Med.Chem.2000,43,2609-2645and references therein.(7)(a)Shaw,P.J.;Ince,P.G.J.Neurol.1997,244(Suppl2),S3-S14.(b)Plaitakis,A.;Fesdjian,C.O.;Shashidharan,S Drugs1996,5,437-456.(8)Frantz,A.;Smith,A.Nat.Re V.Drug Dico V ery2003,2,9.Published on Web12/30/200310.1021/ja035671m CCC:$27.50©2004American Chemical Society J.AM.CHEM.SOC.2004,126,823-8339823There are many types of receptors able to interact with carboxylic acids and amino acids in organic solvents,10-13yielding selective complexation in some instances.However,the number of reported receptors of glutamate in aqueous solution is very scarce.In this sense,one of the few reports concerns an optical sensor based on a Zn(II)complex of a 2,2′:6′,2′′-terpyridine derivative in which L -aspartate and L -glutamate were efficiently bound as axial ligands (K s )104-105M -1)in 50/50water/methanol mixtures.14Among the receptors employed for carboxylic acid recogni-tion,the polyamine macrocycles I -IV in Chart 1are of particular relevance to this work.In a seminal paper,Lehn et al.15showed that saturated polyamines I and II could exert chain-length discrimination between different R ,ω-dicarboxylic acids as a function of the number of methylene groups between the two triamine units of the receptor.Such compounds were also able to interact with a glutamic acid derivative which has the ammonium group protected with an acyl moiety.15,16Compounds III and IV reported by Gotor and Lehn interact in their protonated forms in aqueous solution with protected N -acetyl-L -glutamate and N -acetyl-D -glutamate,showing a higher stability for the interaction with the D -isomer.17In both reports,the interaction with protected N -acetyl-L -glutamate at physiological pH yields constants of ca.3logarithmic units.Recently,we have shown that 1H -pyrazole-containing mac-rocycles present desirable properties for the binding of dopam-ine.18These polyaza macrocycles,apart from having a highpositive charge at neutral pH values,can form hydrogen bonds not only through the ammonium or amine groups but also through the pyrazole nitrogens that can behave as hydrogen bond donors or acceptors.In fact,Elguero et al.19have recently shown the ability of the pyrazole rings to form hydrogen bonds with carboxylic and carboxylate functions.These features can be used to recognize the functionalities of glutamic acid,the carboxylic and/or carboxylate functions and the ammonium group.Apart from this,the introduction of aromatic donor groups appropriately arranged within the macrocyclic framework or appended to it through arms of adequate length may contribute to the recognition event through π-cation interactions with the ammonium group of L -glutamate.π-Cation interactions are a key feature in many enzymatic centers,a classical example being acetylcholine esterase.20The role of such an interaction in abiotic systems was very well illustrated several years ago in a seminal work carried out by Dougherty and Stauffer.21Since then,many other examples have been reported both in biotic and in abiotic systems.22Taking into account all of these considerations,here we report on the ability of receptors 1[L 1]-6[L 6](Chart 2)to interact with L -glutamic acid.These receptors display structures which differ from one another in only one feature,which helps to obtain clear-cut relations between structure and interaction(9)Rebek,J.,Jr.;Askew,B.;Nemeth,D.;Parris,K.J.Am.Chem.Soc.1987,109,2432-2434.(10)Seel,C.;de Mendoza,J.In Comprehensi V e Supramolecular Chemistry ;Vogtle,F.,Ed.;Elsevier Science:New York,1996;Vol.2,p 519.(11)(a)Sessler,J.L.;Sanson,P.I.;Andrievesky,A.;Kral,V.In SupramolecularChemistry of Anions ;Bianchi,A.,Bowman-James,K.,Garcı´a-Espan ˜a,E.,Eds.;John Wiley &Sons:New York,1997;Chapter 10,pp 369-375.(b)Sessler,J.L.;Andrievsky,A.;Kra ´l,V.;Lynch,V.J.Am.Chem.Soc.1997,119,9385-9392.(12)Fitzmaurice,R.J.;Kyne,G.M.;Douheret,D.;Kilburn,J.D.J.Chem.Soc.,Perkin Trans.12002,7,841-864and references therein.(13)Rossi,S.;Kyne,G.M.;Turner,D.L.;Wells,N.J.;Kilburn,J.D.Angew.Chem.,Int.Ed.2002,41,4233-4236.(14)Aı¨t-Haddou,H.;Wiskur,S.L.;Lynch,V.M.;Anslyn,E.V.J.Am.Chem.Soc.2001,123,11296-11297.(15)Hosseini,M.W.;Lehn,J.-M.J.Am.Chem.Soc.1982,104,3525-3527.(16)(a)Hosseini,M.W.;Lehn,J.-M.Hel V .Chim.Acta 1986,69,587-603.(b)Heyer,D.;Lehn,J.-M.Tetrahedron Lett.1986,27,5869-5872.(17)(a)Alfonso,I.;Dietrich,B.;Rebolledo,F.;Gotor,V.;Lehn,J.-M.Hel V .Chim.Acta 2001,84,280-295.(b)Alfonso,I.;Rebolledo,F.;Gotor,V.Chem.-Eur.J.2000,6,3331-3338.(18)Lamarque,L.;Navarro,P.;Miranda,C.;Ara ´n,V.J.;Ochoa,C.;Escartı´,F.;Garcı´a-Espan ˜a,E.;Latorre,J.;Luis,S.V.;Miravet,J.F.J.Am.Chem.Soc .2001,123,10560-10570.(19)Foces-Foces,C.;Echevarria,A.;Jagerovic,N.;Alkorta,I.;Elguero,J.;Langer,U.;Klein,O.;Minguet-Bonvehı´,H.-H.J.Am.Chem.Soc.2001,123,7898-7906.(20)Sussman,J.L.;Harel,M.;Frolow,F.;Oefner,C.;Goldman,A.;Toker,L.;Silman,I.Science 1991,253,872-879.(21)Dougherty,D.A.;Stauffer,D.A.Science 1990,250,1558-1560.(22)(a)Sutcliffe,M.J.;Smeeton,A.H.;Wo,Z.G.;Oswald,R.E.FaradayDiscuss.1998,111,259-272.(b)Kearney,P.C.;Mizoue,L.S.;Kumpf,R.A.;Forman,J.E.;McCurdy,A.;Dougherty,D.A.J.Am.Chem.Soc.1993,115,9907-9919.(c)Bra ¨uner-Osborne,H.;Egebjerg,J.;Nielsen,E.;Madsen,U.;Krogsgaard-Larsen,P.J.Med.Chem.2000,43,2609-2645.(d)Zacharias,N.;Dougherty,D.A.Trends Pharmacol.Sci.2002,23,281-287.(e)Hu,J.;Barbour,L.J.;Gokel,G.W.J.Am.Chem.Soc.2002,124,10940-10941.Chart 1.Some Receptors Employed for Dicarboxylic Acid and N -AcetylglutamateRecognitionChart 2.New 1H -Pyrazole-Containing Polyamine Receptors Able To Complex L -Glutamate inWaterA R T I C L E SMiranda et al.824J.AM.CHEM.SOC.9VOL.126,NO.3,2004strengths.1[L1]and2[L2]differ in the N-benzylation of the pyrazole moiety,and1[L1]and3[L3]differ in the presence in the center of the polyamine side chains of an amino group or of a methylene group.The receptors4[L4]and5[L5]present the central nitrogens of the chain N-functionalized with benzyl or phenethyl groups,and6[L6]has large hydrophobic octyl groups.Results and DiscussionSynthesis of3-6.Macrocycles3-6have been obtained following the procedure previously reported for the preparation of1and2.23The method includes a first dipodal(2+2) condensation of the1H-pyrazol-3,5-dicarbaldehyde7with the corresponding R,ω-diamine,followed by hydrogenation of the resulting Schiff base imine bonds.In the case of receptor3,the Schiff base formed by condensation with1,5-pentanediamine is a stable solid(8,mp208-210°C)which precipitated in68% yield from the reaction mixture.Further reduction with NaBH4 in absolute ethanol gave the expected tetraazamacrocycle3, which after crystallization from toluene was isolated as a pure compound(mp184-186°C).In the cases of receptors4-6, the precursor R,ω-diamines(11a-11c)(Scheme1B)were obtained,by using a procedure previously described for11a.24 This procedure is based on the previous protection of the primary amino groups of1,5-diamino-3-azapentane by treatment with phthalic anhydride,followed by alkylation of the secondary amino group of1,5-diphthalimido-3-azapentane9with benzyl, phenethyl,or octyl bromide.Finally,the phthalimido groups of the N-alkyl substituted intermediates10a-10c were removed by treatment with hydrazine to afford the desired amines11a-11c,which were obtained in moderate yield(54-63%).In contrast with the behavior previously observed in the synthesis of3,in the(2+2)dipodal condensations of7with 3-benzyl-,3-phenethyl-,and3-octyl-substituted3-aza-1,5-pentanediamine11a,11b,and11c,respectively,there was not precipitation of the expected Schiff bases(Scheme1A). Consequently,the reaction mixtures were directly reduced in situ with NaBH4to obtain the desired hexaamines4-6,which after being carefully purified by chromatography afforded purecolorless oils in51%,63%,and31%yield,respectively.The structures of all of these new cyclic polyamines have been established from the analytical and spectroscopic data(MS(ES+), 1H and13C NMR)of both the free ligands3-6and their corresponding hydrochloride salts[3‚4HCl,4‚6HCl,5‚6HCl, and6‚6HCl],which were obtained as stable solids following the same procedure previously reported18for1‚6HCl and2‚6HCl.As usually occurs for3,5-disubstituted1H-pyrazole deriva-tives,either the free ligands3-6or their hydrochlorides show very simple1H and13C NMR spectra,in which signals indicate that,because of the prototropic equilibrium of the pyrazole ring, all of these compounds present average4-fold symmetry on the NMR scale.The quaternary C3and C5carbons appear together,and the pairs of methylene carbons C6,C7,and C8are magnetically equivalent(see Experimental Section).In the13C NMR spectra registered in CDCl3solution, significant differences can be observed between ligand3,without an amino group in the center of the side chain,and the N-substituted ligands4-6.In3,the C3,5signal appears as a broad singlet.However,in4-6,it almost disappears within the baseline of the spectra,and the methylene carbon atoms C6and C8experience a significant broadening.Additionally,a remark-able line-broadening is also observed in the C1′carbon signals belonging to the phenethyl and octyl groups of L5and L6, respectively.All of these data suggest that as the N-substituents located in the middle of the side chains of4-6are larger,the dynamic exchange rate of the pyrazole prototropic equilibrium is gradually lower,probably due to a relation between proto-tropic and conformational equilibria.Acid-Base Behavior.To follow the complexation of L-glutamate(hereafter abbreviated as Glu2-)and its protonated forms(HGlu-,H2Glu,and H3Glu+)by the receptors L1-L6, the acid-base behavior of L-glutamate has to be revisited under the experimental conditions of this work,298K and0.15mol dm-3.The protonation constants obtained,included in the first column of Table1,agree with the literature25and show that the zwitterionic HGlu-species is the only species present in aqueous solution at physiological pH values(Scheme2and Figure S1of Supporting Information).Therefore,receptors for(23)Ara´n,V.J.;Kumar,M.;Molina,J.;Lamarque,L.;Navarro,P.;Garcı´a-Espan˜a,E.;Ramı´rez,J.A.;Luis,S.V.;Escuder,.Chem.1999, 64,6137-6146.(24)(a)Yuen Ng,C.;Motekaitis,R.J.;Martell,A.E.Inorg.Chem.1979,18,2982-2986.(b)Anelli,P.L.;Lunazzi,L.;Montanari,F.;Quici,.Chem.1984,49,4197-4203.Scheme1.Synthesis of the Pyrazole-Containing MacrocyclicReceptorsNew1H-Pyrazole-Containing Polyamine Receptors A R T I C L E SJ.AM.CHEM.SOC.9VOL.126,NO.3,2004825glutamate recognition able to address both the negative charges of the carboxylate groups and the positive charge of ammonium are highly relevant.The protonation constants of L 3-L 6are included in Table 1,together with those we have previously reported for receptors L 1and L 2.23A comparison of the constants of L 4-L 6with those of the nonfunctionalized receptor L 1shows a reduced basicity of the receptors L 4-L 6with tertiary nitrogens at the middle of the polyamine bridges.Such a reduction in basicity prevented the potentiometric detection of the last protonation for these ligands in aqueous solution.A similar reduction in basicity was previously reported for the macrocycle with the N -benzylated pyrazole spacers (L 2).23These diminished basicities are related to the lower probability of the tertiary nitrogens for stabilizing the positive charges through hydrogen bond formation either with adjacent nonprotonated amino groups of the molecule or with water molecules.Also,the increase in the hydrophobicity of these molecules will contribute to their lower basicity.The stepwise basicity constants are relatively high for the first four protonation steps,which is attributable to the fact that these protons can bind to the nitrogen atoms adjacent to the pyrazole groups leaving the central nitrogen free,the electrostatic repulsions between them being therefore of little significance.The remaining protonation steps will occur in the central nitrogen atom,which will produce an important increase in the electrostatic repulsion in the molecule and therefore a reduction in basicity.As stated above,the tertiary nitrogen atoms present in L 4-L 6will also contribute to this diminished basicity.To analyze the interaction with glutamic acid,it is important to know the protonation degree of the ligands at physiological pH values.In Table 2,we have calculated the percentages ofthe different protonated species existing in solution at pH 7.4for receptors L 1-L 6.As can be seen,except for the receptor with the pentamethylenic chains L 3in which the tetraprotonated species prevails,all of the other systems show that the di-and triprotonated species prevail,although to different extents.Interaction with Glutamate.The stepwise constants for the interaction of the receptors L 1-L 6with glutamate are shown in Table 3,and selected distribution diagrams are plotted in Figure 1A -C.All of the studied receptors interact with glutamate forming adduct species with protonation degrees (j )which vary between 8and 0depending on the system (see Table 3).The stepwise constants have been derived from the overall association constants (L +Glu 2-+j H +)H j LGlu (j -2)+,log j )provided by the fitting of the pH-metric titration curves.This takes into account the basicities of the receptors and glutamate (vide supra)and the pH range in which a given species prevails in solution.In this respect,except below pH ca.4and above pH 9,HGlu -can be chosen as the protonated form of glutamate involved in the formation of the different adducts.Below pH 4,the participation of H 2Glu in the equilibria has also to be considered (entries 9and 10in Table 3).For instance,the formation of the H 6LGlu 4+species can proceed through the equilibria HGlu -+H 5L 5+)H 6LGlu 4+(entry 8,Table 3),and H 2Glu +H 4L 4+)H 6LGlu 4(entry 9Table 3),with percentages of participation that depend on pH.One of the effects of the interaction is to render somewhat more basic the receptor,and somewhat more acidic glutamic acid,facilitating the attraction between op-positely charged partners.A first inspection of Table 3and of the diagrams A,B,and C in Figure 1shows that the interaction strengths differ markedly from one system to another depending on the structural features of the receptors involved.L 4is the receptor that presents the highest capacity for interacting with glutamate throughout all of the pH range explored.It must also be remarked that there are not clear-cut trends in the values of the stepwise constants as a function of the protonation degree of the receptors.This suggests that charge -charge attractions do not play the most(25)(a)Martell,E.;Smith,R.M.Critical Stability Constants ;Plenum:NewYork,1975.(b)Motekaitis,R.J.NIST Critically Selected Stability Constants of Metal Complexes Database ;NIST Standard Reference Database,version 4,1997.Table 1.Protonation Constants of Glutamic Acid and Receptors L 1-L 6Determined in NaCl 0.15mol dm -3at 298.1KreactionGluL 1aL 2aL 3bL 4L 5L 6L +H )L H c 9.574(2)d 9.74(2)8.90(3)9.56(1)9.25(3)9.49(4)9.34(5)L H +H )L H 2 4.165(3)8.86(2)8.27(2)8.939(7)8.38(3)8.11(5)8.13(5)L H 2+H )L H 3 2.18(2)7.96(2) 6.62(3)8.02(1) 6.89(5)7.17(6)7.46(7)L H 3+H )L H 4 6.83(2) 5.85(4)7.63(1) 6.32(5) 6.35(6) 5.97(8)L H 4+H )L H 5 4.57(3) 3.37(4) 2.72(8) 2.84(9) 3.23(9)L H 5+H )L H 6 3.18(3) 2.27(6)∑log K H n L41.135.334.233.634.034.1aTaken from ref 23.b These data were previously cited in a short communication (ref 26).c Charges omitted for clarity.d Values in parentheses are the standard deviations in the last significant figure.Scheme 2.L -Glutamate Acid -BaseBehaviorTable 2.Percentages of the Different Protonated Species at pH 7.4H 1L aH 2LH 3LH 4LL 11186417L 21077130L 3083458L 4083458L 51154323L 6842482aCharges omitted for clarity.A R T I C L E SMiranda et al.826J.AM.CHEM.SOC.9VOL.126,NO.3,2004outstanding role and that other forces contribute very importantly to these processes.26However,in systems such as these,which present overlapping equilibria,it is convenient to use conditional constants because they provide a clearer picture of the selectivity trends.27These constants are defined as the quotient between the overall amounts of complexed species and those of free receptor and substrate at a given pH[eq1].In Figure2are presented the logarithms of the effective constants versus pH for all of the studied systems.Receptors L1and L2with a nonfunctionalized secondary amino group in the side chains display opposite trend from all other receptors. While the stability of the L1and L2adducts tends to increase with pH,the other ligands show a decreasing interaction. Additionally,L1and L2present a close interaction over the entire pH range under study.The tetraaminic macrocycle L3is a better(26)Escartı´,F.;Miranda,C.;Lamarque,L.;Latorre,J.;Garcı´a-Espan˜a,E.;Kumar,M.;Ara´n,V.J.;Navarro,mun.2002,9,936-937.(27)(a)Bianchi,A.;Garcı´a-Espan˜a,c.1999,12,1725-1732.(b)Aguilar,J.A.;Celda,B.;Garcı´a-Espan˜a,E.;Luis,S.V.;Martı´nez,M.;Ramı´rez,J.A.;Soriano,C.;Tejero,B.J.Chem.Soc.,Perkin Trans.22000, 7,1323-1328.Table3.Stability Constants for the Interaction of L1-L6with the Different Protonated Forms of Glutamate(Glu) entry reaction a L1L2L3L4L5L6 1Glu+L)Glu L 3.30(2)b 4.11(1)2HGlu+L)HGlu L 3.65(2) 4.11(1) 3.68(2) 3.38(4) 3Glu+H L)HGlu L 3.89(2) 4.48(1) 3.96(2) 3.57(4) 4HGlu+H L)H2Glu L 3.49(2) 3.89(1) 2.37(4) 3.71(2)5HGlu+H2L)H3Glu L 3.44(2) 3.73(1) 2.34(3) 4.14(2) 2.46(4) 2.61(7) 6HGlu+H3L)H4Glu L 3.33(2) 3.56(2) 2.66(3) 4.65(2) 2.74(3) 2.55(7) 7HGlu+H4L)H5Glu L 3.02(2) 3.26(2) 2.58(3) 4.77(2) 2.87(3) 2.91(5) 8HGlu+H5L)H6Glu L 3.11(3) 3.54(2) 6.76(3) 4.96(3) 4.47(3) 9H2Glu+H4L)H6Glu L 2.54(3) 3.05(2) 3.88(2) 5.35(3) 3.66(4) 3.56(3) 10H2Glu+H5L)H7Glu L 2.61(6) 2.73(4) 5.51(3) 3.57(4) 3.22(8) 11H3Glu+H4L)H7Glu L 4.82(2) 4.12(9)a Charges omitted for clarity.b Values in parentheses are standard deviations in the last significantfigure.Figure1.Distribution diagrams for the systems(A)L1-glutamic acid, (B)L4-glutamic acid,and(C)L5-glutamicacid.Figure2.Representation of the variation of K cond(M-1)for the interaction of glutamic acid with(A)L1and L3,(B)L2,L4,L5,and L6.Initial concentrations of glutamate and receptors are10-3mol dm-3.Kcond)∑[(H i L)‚(H j Glu)]/{∑[H i L]∑[H j Glu]}(1)New1H-Pyrazole-Containing Polyamine Receptors A R T I C L E SJ.AM.CHEM.SOC.9VOL.126,NO.3,2004827receptor at acidic pH,but its interaction markedly decreases on raising the pH.These results strongly suggest the implication of the central nitrogens of the lateral polyamine chains in the stabilization of the adducts.Among the N-functionalized receptors,L4presents the largest interaction with glutamate.Interestingly enough,L5,which differs from L4only in having a phenethyl group instead of a benzyl one,presents much lower stability of its adducts.Since the basicity and thereby the protonation states that L4and L5 present with pH are very close,the reason for the larger stability of the L4adducts could reside on a better spatial disposition for formingπ-cation interactions with the ammonium group of the amino acid.In addition,as already pointed out,L4presents the highest affinity for glutamic acid in a wide pH range,being overcome only by L1and L2at pH values over9.This observation again supports the contribution ofπ-cation inter-actions in the system L4-glutamic because at these pH values the ammonium functionality will start to deprotonate(see Scheme2and Figure1B).Table4gathers the percentages of the species existing in equilibria at pH7.4together with the values of the conditional constant at this pH.In correspondence with Figure1A,1C and Figure S2(Supporting Information),it can be seen that for L1, L2,L5,and L6the prevailing species are[H2L‚HGlu]+and[H3L‚HGlu]2+(protonation degrees3and4,respectively),while for L3the main species are[H3L‚HGlu]+and[H4L‚HGlu]2+ (protonation degrees4and5,respectively).The most effective receptor at this pH would be L4which joins hydrogen bonding, charge-charge,andπ-cation contributions for the stabilization of the adducts.To check the selectivity of this receptor,we have also studied its interaction with L-aspartate,which is a competitor of L-glutamate in the biologic receptors.The conditional constant at pH7.4has a value of3.1logarithmic units for the system Asp-L4.Therefore,the selectivity of L4 for glutamate over aspartate(K cond(L4-glu)/K cond(L4-asp))will be of ca.15.It is interesting to remark that the affinity of L4 for zwiterionic L-glutamate at pH7.4is even larger than that displayed by receptors III and IV(Chart1)with the protected dianion N-acetyl-L-glutamate lacking the zwitterionic charac-teristics.Applying eq1and the stability constants reported in ref17,conditional constants at pH7.4of 3.24and 2.96 logarithmic units can be derived for the systems III-L-Glu and IV-L-Glu,respectively.Molecular Modeling Studies.Molecular mechanics-based methods involving docking studies have been used to study the binding orientations and affinities for the complexation of glutamate by L1-L6receptors.The quality of a computer simulation depends on two factors:accuracy of the force field that describes intra-and intermolecular interactions,and an adequate sampling of the conformational and configuration space of the system.28The additive AMBER force field is appropriate for describing the complexation processes of our compounds,as it is one of the best methods29in reproducing H-bonding and stacking stabiliza-tion energies.The experimental data show that at pH7.4,L1-L6exist in different protonation states.So,a theoretical study of the protonation of these ligands was done,including all of the species shown in5%or more abundance in the potentiometric measurements(Table4).In each case,the more favored positions of protons were calculated for mono-,di-,tri-,and tetraprotonated species.Molecular dynamics studies were performed to find the minimum energy conformations with simulated solvent effects.Molecular modeling studies were carried out using the AMBER30method implemented in the Hyperchem6.0pack-age,31modified by the inclusion of appropriate parameters. Where available,the parameters came from analogous ones used in the literature.32All others were developed following Koll-man33and Hopfinger34procedures.The equilibrium bond length and angle values came from experimental values of reasonable reference compounds.All of the compounds were constructed using standard geometry and standard bond lengths.To develop suitable parameters for NH‚‚‚N hydrogen bonding,ab initio calculations at the STO-3G level35were used to calculate atomic charges compatible with the AMBER force field charges,as they gave excellent results,and,at the same time,this method allows the study of aryl-amine interactions.In all cases,full geometry optimizations with the Polak-Ribiere algorithm were carried out,with no restraints.Ions are separated far away and well solvated in water due to the fact that water has a high dielectric constant and hydrogen bond network.Consequently,there is no need to use counteri-ons36in the modelization studies.In the absence of explicit solvent molecules,a distance-dependent dielectric factor quali-tatively simulates the presence of water,as it takes into account the fact that the intermolecular electrostatic interactions should vanish more rapidly with distance than in the gas phase.The same results can be obtained using a constant dielectric factor greater than1.We have chosen to use a distance-dependent dielectric constant( )4R ij)as this was the method used by Weiner et al.37to develop the AMBER force field.Table8 shows the theoretical differences in protonation energy(∆E p) of mono-,bi-,and triprotonated hexaamine ligands,for the (28)Urban,J.J.;Cronin,C.W.;Roberts,R.R.;Famini,G.R.J.Am.Chem.Soc.1997,119,12292-12299.(29)Hobza,P.;Kabelac,M.;Sponer,J.;Mejzlik,P.;Vondrasek,put.Chem.1997,18,1136-1150.(30)Cornell,W.D.;Cieplak,P.;Bayly,C.I.;Gould,I.R.;Merz,K.M.,Jr.;Ferguson,D.M.;Spelmeyer,D.C.;Fox,T.;Caldwell,J.W.;Kollman,P.A.J.Am.Chem.Soc.1995,117,5179-5197.(31)Hyperchem6.0(Hypercube Inc.).(32)(a)Fox,T.;Scanlan,T.S.;Kollman,P.A.J.Am.Chem.Soc.1997,119,11571-11577.(b)Grootenhuis,P.D.;Kollman,P.A.J.Am.Chem.Soc.1989,111,2152-2158.(c)Moyna,G.;Hernandez,G.;Williams,H.J.;Nachman,R.J.;Scott,put.Sci.1997,37,951-956.(d)Boden,C.D.J.;Patenden,put.-Aided Mol.Des.1999, 13,153-166.(33)/amber.(34)Hopfinger,A.J.;Pearlstein,put.Chem.1984,5,486-499.(35)Glennon,T.M.;Zheng,Y.-J.;Le Grand,S.M.;Shutzberg,B.A.;Merz,K.M.,put.Chem.1994,15,1019-1040.(36)Wang,J.;Kollman,P.A.J.Am.Chem.Soc.1998,120,11106-11114.Table4.Percentages of the Different Protonated Adducts[HGlu‚H j L](j-1)+,Overall Percentages of Complexation,andConditional Constants(K Cond)at pH7.4for the Interaction ofGlutamate(HGlu-)with Receptors L1-L6at Physiological pH[H n L‚HGlu]an)1n)2n)3n)4∑{[H n L‚HGlu]}K cond(M-1)L13272353 2.44×103L2947763 4.12×103L31101324 3.99×102L423737581 2.04×104L51010222 3.51×102L6121224 3.64×102a Charges omitted for clarity.A R T I C L E S Miranda et al. 828J.AM.CHEM.SOC.9VOL.126,NO.3,2004。

几种多齿配体配合物的合成,结构及表征

几种多齿配体配合物的合成,结构及表征本文主要介绍了几种多齿配体配合物的合成、结构及表征。

多齿配体配合物具有多种形式，主要分为含氮、含硫、含磷三种。

本文将以此为基础，分别介绍几种典型的多齿配体配合物的合成、结构与表征。

首先介绍的是一种含氮的多齿配体配合物，即4-邻氨基-2, 6-二甲基吡啶（HNDA）。

它是将氨基与二甲基吡啶稳定的通过氨基和羰基方式发生反应而合成的。

HNDA配合物具有双重酰胺桥形态，其中氨基和邻羰基可以作为配体的一种配位中心，其他两端为甲基及双硝基芳基，构成了一种官能团阵列结构。

HNDA配合物通常显示出偏光度和荧光度，将HNDA与金属离子发生双硫键配位后电导率显著升高，表明它也可以作为一种有效的电导配合物。

此外，还有一种含磷的多齿配体，即2-(4-甲基苯氧基)-6-三(羟甲基)苯基-三聚磷酸酯（MPPA）。

该配合物结构为三聚拓扑结构，在配体中的三个磷原子都连接有三个苯氧基，而苯氧基的甲基又与磷原子通过羟甲基酰基发生反应，形成了一种官能团阵列结构。

MPPA配合物有较强的双硫键配位能力，与金属离子发生反应后，电导率可以显著升高，表明它可以作为一种有效的电导配合物。

最后，介绍的是一种含硫的多齿配体，即1,3-二(pyridinylthio)propane（APT）。

APT配合物中两个硫原子都连接有含有一个吡啶基的丙烷碳链，当APT与金属离子络合时，它们之间形成双硫键配位，氧化还原零价金属离子便会发生变化，使APT立即发光，可以用于生物检测。

总之，本文介绍了几种多齿配体配合物的合成、结构与表征，包括含氮（HNDA）、含磷（MPPA）、含硫（APT）三种。

各自具有不同的配位特性，可以作为金属离子的有效电导配合物，广泛应用于生物检测、医药、催化反应等领域。

多肽合成的书 -回复

多肽合成的书-回复
以下是一些关于多肽合成的书籍推荐：
1. "Peptide Synthesis: A Practical Guide" by Peter R. Schreiber and Alberto Vasquez –这本书详细介绍了多肽合成的基本原理和技术，包括固相和液相合成方法，以及各种修饰和纯化策略。

2. "The Art and Science of Peptide Synthesis" edited by Paul Couvreur –这本论文集汇集了多位专家在多肽合成领域的研究成果和经验分享，涵盖了从基础理论到实际应用的各个方面。

3. "Solid Phase Peptide Synthesis: A Practical Approach" by Barry L. Karger and J. Michael Bassick –这本书专门讨论了固相多肽合成的方法和技术，包括合成策略、试剂选择、纯化和分析等关键步骤。

4. "Peptide Chemistry: A Practical Textbook" by Hiroaki Suga –这本书全面介绍了肽化学的基础知识和实验技术，包括多肽合成、结构测定、功能研究等内容，适合初学者和研究人员参考。

5. "Advanced Techniques in Protein Chemistry" edited by John M. Walker –这本论文集包含了许多关于蛋白质和多肽合成、表征和功能研究的高级技术，对于深入研究该领域的研究人员非常有帮助。

以上这些书籍都是多肽合成领域的重要参考资料，可以根据自己的需求和水平选择合适的读物。

过氧化氢诱导依赖于metacaspase的禾谷镰刀菌细胞调亡研究

论文提交日期：2018年5月论文答辩日期：2018年6月学位授予日期：2018年6月学科类别：农学答辩委员会主席：陈功友教授符号说明H2O2: Hydrogen peroxide, 过氧化氢DAPI: 4`, 6-Diamidino-2-phenylindole, 4,6-二氨基-2-苯基吲哚二盐酸盐TUNEL: Terminal-deoxynucleotidyl transferase mediated nick end labeling, 原位末端标记Amp+: Ampicillin, 氨苄青霉素CMC: Carboxymethyl cellulose, 羧甲基纤维素CTAB: Hexadecyl trimethyl ammonium Bromide, 十六烷基三甲基溴化铵ddH2O: Double distilled water, 双蒸水DNA: Deoxyribonucleic acid, 脱氧核糖核酸FHB: Fusarium head blight, 小麦赤霉病G418: Geneticin, 遗传霉素LB: Luria-bertani medium, LB培养基PDA: Potato dextrose agar, 马铃薯培养基PEG: Polyethylene glycol, 聚乙二醇SDS: Sodium dodecyl sulfate, 十二烷基硫酸钠目录中文摘要 (I)Abstract (II)1 前言 (1)1.1 禾谷镰刀菌概述 (1)1.2 细胞凋亡概述 (2)1.3 细胞凋亡在动物与植物中的研究进展 (3)1.3.1 动物细胞凋亡 (4)1.3.2 植物细胞程序性死亡 (5)1.4 酵母菌细胞凋亡 (6)1.5 丝状真菌细胞凋亡研究进展 (8)1.6 研究目的与意义 (10)2 材料与方法 (11)2.1 实验材料 (11)2.1.1 菌株与载体 (11)2.1.2 主要生化试剂及试剂盒 (11)2.1.3 主要培养基配方 (12)2.1.4 溶液与缓冲液配置 (14)2.1.5 PCR引物 (16)2.2 实验方法 (16)2.2.1 禾谷镰刀菌菌种的保存与活化 (16)2.2.2 禾谷镰刀菌分生孢子的收集 (17)2.2.3 H2O2对禾谷镰刀菌菌落生长速度的测定 (17)2.2.4 H2O2对禾谷镰刀菌分生孢子萌发的测定 (17)2.2.5 DAPI染色 (17)2.2.6 TUNEL染色 (18)2.2.7 Annexin V-FITC染色 (19)2.2.8 JC-1染色 (20)2.2.9 Metacaspase原位活性检测 (20)2.2.10 Caspase广谱抑制剂Z-V AD-FMK对metacaspase活性的影响 (21)2.2.11 禾谷镰刀菌metacaspase蛋白的亚细胞定位 (22)3 结果与分析 (26)3.1 H2O2抑制禾谷镰刀菌的菌落生长 (26)3.2 H2O2抑制禾谷镰刀菌分生孢子的萌发 (26)3.3 H2O2诱导禾谷镰刀菌细胞染色质浓缩 (27)3.4 H2O2诱导禾谷镰刀菌细胞DNA断裂 (27)3.5 H2O2诱导禾谷镰刀菌细胞发生细胞磷脂酰丝氨酸外翻 (28)3.6 H2O2诱导禾谷镰刀菌细胞线粒体膜电位的改变 (29)3.7 H2O2诱导的禾谷镰刀菌细胞凋亡依赖于metacaspase (30)3.8 Metacaspases亚细胞定位 (31)4 讨论 (33)5 全文总结与展望 (36)5.1 全文总结 (36)5.2 展望 (37)参考文献 (38)致谢 (47)攻读学位期间发表论文情况 (48)山东农业大学硕士学位论文中文摘要禾谷镰刀菌(Fusarium graminearum)是一种能够侵染植物尤其是小麦和玉米的真菌病原物，是小麦赤霉病（Fusarium head blight, FHB）的主要致病菌，发病后使小麦严重减产从而造成巨大的经济损失。

六配位Ni2+荧光材料制备及近红外发光性能

六配位Ni2+荧光材料制备及近红外发光性能随着近红外光在生物医学、光电子学和光化学等领域的广泛应用，近红外荧光材料的研究备受关注。

六配位Ni2+荧光材料作为一类具有潜在应用前景的近红外发光材料，其制备和性能研究尤为重要。

六配位Ni2+荧光材料的制备方法多种多样，常用的有溶剂热法、水热法和溶剂热氧化法等。

其中，溶剂热法是较为常见的制备方法。

该方法通过在有机溶剂中加热反应体系，使得Ni2+离子和配体发生配位反应，形成六配位Ni2+荧光材料。

此外，水热法利用高温、高压的水热条件下，使得Ni2+离子与配体在水溶液中发生反应，也可有效制备六配位Ni2+荧光材料。

溶剂热氧化法则是通过将Ni2+离子和氧化剂在溶剂中进行反应，形成氧化态的Ni2+离子，并与配体形成六配位结构。

六配位Ni2+荧光材料具有良好的近红外发光性能，其发光峰位通常在700-900 nm之间。

这使得其在生物医学领域中具有潜在的应用价值，如近红外生物成像、荧光探针和光动力疗法等。

此外，六配位Ni2+荧光材料的发光寿命较长，可达到数十毫秒，使其在光电子学领域中广泛应用于光记录、光存储和光通信等方面。

近年来，研究人员还对六配位Ni2+荧光材料的发光机理进行了深入研究。

实验证明，六配位Ni2+荧光材料的近红外发光主要来自于配体的激发和Ni2+离子的能级跃迁。

通过调控配体的结构和化学性质，可以有效调节六配位Ni2+荧光材料的发光性能。

总之，六配位Ni2+荧光材料作为一类具有潜在应用前景的近红外发光材料，其制备和性能研究对于推动近红外光在各个领域的应用具有重要意义。

未来的研究应该进一步探索六配位Ni2+荧光材料的制备方法和发光机理，以提高其发光性能和拓展其应用领域。

Ch6 生物酶工程

Ch6-2 酶分子的定向进化
（Directed Evilution））
酶分子的定向进化是指在分子水平上，酶分子的定向进化是指在分子水平上 1. 酶分子定向进化方法：易错PCR的关键在于一下两点控制：的关键在于一下两点控制：的关键在于一下两点控制易错PCR定向进化的应用实例：定向进化的应用实例：易错酶分子定向进化方法：，人为地创造特殊的进化定向进化的应用实例易错PCR法：易错，模拟自然进化机制（随机突变、基因重组和自然选择），法条件，条件模拟自然进化机制（随机突变、基因重组和自然选择），每个目的基因的突变碱基数要严格控制： ① 每个目的基因的突变碱基数要严格控制：突变率不利用易错PCR定向进化－天冬氨酸酶实例定向进化L－利用易错定向进化目前已经研究成功的酶蛋白分子定向进化方法只要对酶基因进行改造，并进行定向选择， Chain Reaction）对酶基因进行改造，并进行定向选择，筛选出所需性质的酶蛋易错PCR是在利用是在利用PCR（Polymerase 易错是在利用（）应太高，太高时酶的基因突变太大，应太高，太高时酶的基因突变太大，酶固有活力不易包括一下几个方面：包括一下几个方面设计工作程序：易错PCR→筛选突变体（优势突变设计工作程序：易错：，对目的基因进行扩增，白。技术在Taq聚合酶的催化下筛选突变体聚合酶的催化下，对目的基因进行扩增，技术在聚合酶的催化下筛选突变体→（重组→筛选重组太低不易实现酶分子的有效进化，一般理论上保持，筛选）；方法；太低不易实现酶分子的有效进化，保持，筛选）；方法主要包括两个方面，即酶分子改造的合对酶蛋白分子的改造，； Mg 2＋浓度、加入Mn 2＋改对酶蛋白分子的改造，主要包括两个方面，易错PCR方法易错通过调整反应条件（提高Mg 2＋浓度、加入Mn 2＋通过调整反应条件（提高讲每个靶基因导入的突变碱基数控制在1.5～5个；并讲每个靶基因导入的突变碱基数控制在 Irrational Design）理化设计（理化设计（Rational Design）和非合理设计倍的突变体；）和非合理设计（～个（研究结果：获得了一株酶活力提高28倍的突变体）研究结果：获得了一株酶活力提高倍的突变体；酶 DNA改组方法；改组方法；改组方法的比例浓度等变反应体系中四种dNTP的比例浓度等），改变的比例浓度等）改变Taq酶变反应体系中四种且进化酶的pH稳定性和热稳定性都明显优于原始酶。稳定性和热稳定性都明显优于原始酶。且进化酶的：主要指事先已经搞清楚了酶蛋白的结构，有明确合理化设计：稳定性和热稳定性都明显优于原始酶 ② 合理化设计主要指事先已经搞清楚了酶蛋白的结构，一般一次突变很难获得有用突变，所以在设计易错一般一次突变很难获得有用突变，催化的目的基因扩增中的突变频率，；催化的目的基因扩增中的突变频率，以一定的频率随基因家族之间的同源重组方法；基因家族之间的同源重组方法的修饰目标，的修饰目标，定点改造某一结构活某氨基酸而设计的改造修饰进一步测序研究表明进化后的突变体共发生了7个碱基进一步测序研究表明进化后的突变体共发生了个碱基 PCR时，是设计连续易错扩增，时是设计连续易错PCR 扩增，连续进行随机突机构件了基因突变库，、酶蛋白基因的定点突变等；机构件了基因突变库，然后选择或筛选符合需要的突方案，如酶蛋白的化学修饰、方案，如酶蛋白的化学修饰酶蛋白基因的定点突变等；突变，其中3个突变位点引起了氨基酸的改变突变，其中个突变位点引起了氨基酸的改变从而获得符合进化目的的突变体。变，从而获得符合进化目的的突变体。变体。变体。非合理设计：事先不必确定基因的改造修饰目标，非合理设计：事先不必确定基因的改造修饰目标，设计酶蛋 Asn217→Lys； Thr233 →Arg； Val367 →Gly ；；白基因改造技术和方法，设计基因改造方案，白基因改造技术和方法，设计基因改造方案，然后按照预定目标要求，进行筛选。酶分子的定向进化就属于非合理设计。标要求，进行筛选。酶分子的定向进化就属于非合理设计。