蜂王浆化学成分的研究(Ⅰ)——反-10-羟基-癸烯-2-酸的分离和鉴定

蜂王浆为我国常用的补药,能治疗多种疾病,并有抗辐射作用。我们从蜂王浆中分离出一种白色晶体,经红外光谱、核磁共振谱、质谱及化学方法测定其为反-10-羟基-癸烯-2-酸。已证明这个化合物具有抗菌作用和抗癌作用,但尚未见到有关其抗辐射作用的报导。     

4-硝基-1,3-丁二烯基胺分子的氢键效应

在从头计算的水平上, 利用杂化密度泛函理论研究了溶剂对4-硝基-1,3-丁二烯基胺分子的几何结构、分子内的电荷分布和电荷转移态的能量漂移的影响. 在四种极性溶剂中, 我们构造了包括氢键作用的超分子结构. 分别研究了由极化连续模型模拟的溶剂和溶质分子的长程相互作用, 溶剂和溶质分子的氢键作用, 以及溶剂和溶质分子的整体作用对分子结构和性质的影响. 研究结果表明氢键作用引起了溶质分子结构和性质的较大变化, 从而将明显地影响该类分子的非线性光学性质. 因此, 在模拟溶剂效应时需要考虑氢键作用.     

1-苯基-3-甲基-4-苯甲酰吡唑啉酮-5萃取镓的研究

首次报道了1-苯基-3-甲基-4-苯甲酰吡唑啉酮-5(HPMBP)萃取镓的热力学和动力学, 指出在体系中形成Ga(PMBP)3(H2O)2萃合物, 配体PMBP既有一次溶剂化作用, 又有二次溶剂化作用, 并得到红外光谱和核磁共振谱的证实。镓的萃取过程为水相化学反应控制, 决速步骤为一次溶剂化过程: Ga^3^++HPMBP→Ga(PMBP)^2^++H^+。添加剂三辛基氧化膦(TOPO)不影响HPMBP萃取镓的分配比, 但降低了HPMBP萃取镓的正向速率, 表明动力学抑萃作用与热力学抑萃作用无对应关系。     

2-芳基-4-氧-4 H-吡喃酮[3,2-c]-9-溴喹啉类化合物的合成

黄酮类化合物广泛存在于埴物体中,具有广泛的生物活性,其研究发展很快,但对于氮杂黄酮类化合物的研究工作却甚少。含氮黄酮类化合物具有抗癌、抗菌、冠状动脉扩张等作用。但是,目前黄酮类药物仍存在以下问题:(1)黄酮类化合物结构繁多,生物活性极其广泛,但作用强度普遍较弱;(2)黄酮类化合物水溶性较低,影响药物的吸收与疗效。新型黄酮类化合物的合成仍有一定的意义。     

3,4-去氢-3-羟基-4-苯基-2,5-吡喃二酮的合成

Merck研究小组于1999年报道了一类醌类化合物具有类似胰岛素的作用[1],体内口服给药具有显著的降糖作用,目前在治疗糖尿病方面极具前景。其中3,4 去氢 3 羟基 2,5 吡喃二酮(3)是合成这类醌类化合物的重要中间体。本文报道了该中间体3,4 去氢 3 羟基 4 苯基 2,5 吡喃二酮的合成。合成路线如下图所示。其中化合物的结构均通过熔点、MS、IR、1HNMR确证。1　实验部分1 1　仪器与试剂XRC 1型显微熔点仪测定(温度计未经校正),四川大学科仪厂;Nicolet200SXV傅立叶变换红外光谱仪(石蜡油油湖法),Nicolet公司制造;FinniganLCQDECA型质…     

甲基丙烯酸-8-羟基喹啉-镧配合物的合成及与DNA的作用

合成了配合物La(C4H6O2)2(hq)(C4H6O2=甲基丙烯酸,hq=8-羟基喹啉),通过元素分析、摩尔电导、红外光谱、紫外光谱和热重分析手段对产物进行表征。此外,采用紫外吸收光谱、荧光光谱,研究了配合物与鲱鱼精DNA之间的相互作用。结果显示配合物与鲱鱼精DNA作用的结合常数K=7.59×103L·mol-1,配合物与DNA的作用摩尔比为1∶1,作用模式为嵌插作用。     

1-(2-氨基-3,5-二氰基-4-芳基-4H-吡喃-6-基)愈创兰烃薁的合成

在醋酸铵作用下,通过1-氰乙酰基愈创兰烃薁、芳香醛、丙二腈的三组分反应,一锅法合成了一系列1-(2-氨基-3,5-二氰基-4-芳基-4H-吡喃-6-基)愈创兰烃薁衍生物.该反应操作简单、条件温和、收率良好.产物结构经NMR,MS,IR及元素分析等得以证实.     

1-(4-溴苯基)-5-苯基-1H-1,2,3-三氮唑键合人血清白蛋白的作用机制及抗菌活性

利用化学信息学、多种光谱法及抗菌实验,研究了1-(4-溴苯基)-5-苯基-1H-1,2,3-三唑(1-(4-bromophenyl)-5-phenyl-1H-1,2,3-triazole,BPTA)键合人血清白蛋白(HSA)的作用机制及抗菌活性。研究了BPTA的荧光光谱及紫外光谱;分子模拟确定了BPTA与HSA的键合区域和模式,位点竞争实验确定了BPTA在HSA亚结构域的位点Ⅱ发生作用。利用荧光偏振、紫外光谱、同步及三维荧光方法在模拟生理条件下研究了BPTA与HSA的作用机制及对蛋白微环境和二级结构的影响,并求得不同温度下BPTA与HSA作用的键合参数和热力学参数,确定了键合模式主要是疏水力作用、氢键及范德华作用。从分子水平上揭示了BPTA与HSA相互作用的机制,说明BPTA在生理条件下能被HSA载运至靶位发挥药效。另外,抗菌实验表明,BPTA对白色葡萄球菌、金黄色葡萄球菌、枯草芽孢杆菌、蜡状芽孢杆菌、四联球菌及白色念珠菌6种菌类均有明显的抑制作用。     

2-(2-羟基-5-氨苯基)苯并咪唑与氨基卟啉能量转移的研究

采用紫外光谱法和荧光光谱法研究了二氯甲烷溶液中2-(2-羟基-5-氨基苯基)苯并咪唑(NH_2-HBI)和5-(4-氨基)苯基-10,15,20-三苯基卟啉(NH_2-TPP)两分子之间的能量转移作用,测定了NH_2-HBI与NH_2-TPP作用的结合比及能量转移参数.结果表明,在光的激发作用下,形成了以NH_2-HBI为能量供体、NH_2-TPP为能量受体的荧光共振能量转移(FRET)体系,同时发生了NH_2-HBI激发态分子内质子转移(ESIPT)与FRET的耦合作用, NH_2-HBI分子的醇式构型与酮式构型的荧光都被部分的猝灭,而NH_2-TPP的荧光却明显的增强.两分子形成了1∶1的供体-受体作用分子对,体系的FRET能量转移效率(E_(FRET))为0.114,临界能量转移距离(R_0)为2.293nm,供-受体之间的距离(r)为3.227 nm.     

3-甲基-1-苯基-4-{4-([5-甲基-2-(4-取代芳基)-噁唑-4-基]甲氧基)-芳亚甲(苄)基}-2-吡唑啉-5-酮的设计、合成与降血糖活性

设计合成了具有降血糖活性的3-甲基-1-苯基-4-[4-[[5-甲基-2-(4-取代芳基)-噁唑-4-基]甲氧基]-芳亚甲(苄)基]}-2-吡唑啉-5-酮类化合物.用丁二酮单肟和(取代的)苯甲醛环合、氯化得到氯甲基噁唑衍生物,与对羟基苯甲醛或香兰醛缩合,再与3-甲基-1-苯基-2-吡唑啉-5-酮进行Knoevenagel反应及催化氢化得到目标化合物(Ⅰ和Ⅱ),共合成了16个未见文献报道的新化合物,并利用元素分析、IR、MS和1HNMR确证了化合物的结构.初步药理试验结果表明,所合成的化合物有抑制血糖升高的倾向以及能明显加强和延长外源性胰岛素的降血糖作用,其中化合物Ⅰb,Ⅰd和Ⅰf尤为突出,说明这类化合物可能有增强胰岛素敏感性的作用.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.