2,9-二甲基-1,10-菲咯啉的l-缬氨酸衍生物的合成表征及其镧(Ⅲ)配合物与DNA作用光谱研究

以2,9-二甲基-1,10-菲咯啉为初始原料,合成了1,10-菲咯啉的l-缬氨酸衍生物------1,10-菲咯啉-2,9二亚甲基亚氨基-(2,2'-二异丙基)二乙酸(L)。该配体经过元素分析、红外光谱、核磁共振氢谱表征。通过电子光谱,研究了La(Ⅲ)的配合物与小牛胸腺DNA的相互作用。用溴化乙锭作为荧光探针,还研究了La(Ⅲ)-L配合物与小牛胸腺DNA的相互作用的过程。作为对比,也研究了La(Ⅲ)分别与1,10-菲咯啉(Phen)、l-缬氨酸(Val)的配合物与小牛胸腺DNA的相互作用。结果表明La(Ⅲ)-L配合物与小牛胸腺DNA作用既有共价键合,又有插入作用。     

2,9-二甲基-1,10-菲咯啉的l-缬氨酸衍生物的合成表 征及其镧(Ⅲ)配合物与 DNA作用光谱研究

以2,9-二甲基-1,10-菲咯啉为初始原料,合成了1,10-菲咯啉的l-缬氨酸衍生物------1,10-菲咯啉-2,9二亚甲基亚氨基-(2,2'-二异丙基)二乙酸(L)。该配体经过元素分析、红外光谱、核磁共振氢谱表征。通过电子光谱,研究了La(Ⅲ)的配合物与小牛胸腺DNA的相互作用。用溴化乙锭作为荧光探针,还研究了La(Ⅲ)-L配合物与小牛胸腺DNA的相互作用的过程。作为对比,也研究了La(Ⅲ)分别与1,10-菲咯啉(Phen)、l-缬氨酸(Val)的配合物与小牛胸腺DNA的相互作用。结果表明La(Ⅲ)-L配合物与小牛胸腺DNA作用既有共价键合,又有插入作用。     

表面活性剂中DNA构象变化的研究

以荧光探针法研究了表面活性剂与小牛胸腺DNA的相互作用，结果表明：阳离子表面活性剂主要通过静电引力和疏水方式与DNA作用；阴离子表面活性剂与DNA之间存在静电排斥力，两者之间的相互作用不太明显；而非离子表面活性剂与DNA的相互作用类似于有机溶剂对DNA的影响，即通过溶液的极性、粘度和介电常数来影响DNA的构象，表面活性剂使得DNA构象发生较大的变化，预示了它可能使DNA的生物功能发生较大的变化。     

甲氨蝶呤与DNA相互作用的荧光光谱研究

在pH 7.4的Tris-HCI介质中,以盐酸小檗碱为荧光探针,研究了甲氨蝶呤与小牛胸腺DNA之间的相互作用.采用荧光光谱、吸收光谱、Scatchard方程、盐效应等手段,对作用机理进行了研究,结果表明甲氨蝶呤与小牛胸腺DNA之间的作用方式为混合方式,嵌入与静电作用是两种主要作用方式.求得25℃和40℃时二者的结合常数分别为5.61 × 104和5.32×104L·mol-1.     

p-HPcZn与CT DNA相互作用

在检测β-四(羧基苯氧基)锌酞菁(p-HPcZn)光敏性能的基础上,利用吸收光谱和荧光光谱分析技术研究了p-HPcZn与小牛胸腺脱氧核糖核酸(CT DNA)的相互作用机理.研究结果表明,p-HPcZn能以嵌插的形式与CT DNA发生作用;无论是在有氧或是在无氧的条件下,p-HPcZn对CT DNA的光敏损伤能力均高于血卟咻.     

2,9-二甲基-1,10-菲咯啉的dl-丙氨酸衍生物的合成表征及其镧(III)配合物与DNA作用光谱研究

以2,9-二甲基-1,10-菲咯啉为初始原料,合成了2,9-二甲基-1,10-菲咯啉的dl-丙氨酸衍生物:1,10-菲咯啉-2,9-二亚甲基亚氨基-(2,2'-二甲基)二乙酸(L).该配体经过元素分析、红外光谱、核磁共振氢谱表征.在25±0.1℃、I=0.1mol·dm-3NaNO3的条件下,用pH电位滴定法测定了该配体的质子化常数及其与 La(III)的配合物的稳定常数.通过电子光谱研究了La(III)的配合物与小牛胸腺DNA的相互作用.用溴化乙锭作为荧光探针研究了La(III)-L配合物与小牛胸腺DNA的相互作用的过程.作为对比,也研究了La(III)分别与 1,10-菲咯啉(Phen)、dl-丙氨酸(Ala)的配合物与小牛胸腺DNA的相互作用.结果表明La(III)-L配合物与小牛胸腺DNA作用既有共价键合,又有插入作用.     

不可逆电活性药物米托蒽醌与脱氧核糖核酸的相互作用

研究了抗癌新药米托蒽醌(MXT)的电化学行为及与脱氧核糖核酸(DNA)的相互作用，推导了适用于研究不可逆电活性分子与DNA相互作用的电化学公式，运用该公式可以简便、快速地测定靶向分子与DNA的结合常数和结合位点数。实验发现，MXT与小牛胸腺DNA的结合以蒽醌母核的嵌插作用为主，同时，烃氨基侧链与骨架磷酸基团之间的静电吸引对母核起稳定作用，使化合物易于嵌入DNA的平面结构。MXT与DNA相互作用引起的峰电流的变化可以用于分析测定DNA。     

紫外共振Raman研究插入类抗癌药物与DNA相互作用

本文首次用紫外共振Raman光谱方法研究了典型插入类抗癌药物ADM(Adriamycin)和ACM(Aclacinomycin)与小牛胸腺DNA相互作用特性。结果表明,用紫外共振Raman可以得到药物分子插入DNA的位置,药物与DNA之间的电子相互作用以及与DNA形成的氢键等方面的重要信息,也可以反映药物对DNA碱基对之间氢键和DNA构象的影响。     

土霉素的电化学性质及其与DNA相互作用的研究

研究了土霉素在玻碳电极上的电化学行为。并利用电化学方法研究了土霉素与小牛胸腺DNA(ctDNA)的相互作用,DNA的存在能导致土霉素还原峰电流降低,峰电位正移,推测土霉素与DNA在该条件下以键合模式相互结合。紫外-可见吸收光谱的研究进一步确证了上述结果。     

下沿含苯磺酰基杯芳烃衍生物与Eu3+配合物的光谱性质研究

下沿含苯磺酰基团杯芳烃衍生物 (L) 与Eu3+形成配合物的光谱性质研究结果证明, 在乙腈溶液中L与Eu3+之间能有效的发生能量转移, 配位计量比为1∶1, 配位稳定常数Ks为5.86×104; 初步探讨了能量转移机制和L·Eu3+ 配合物与小牛胸腺DNA的相互作用.     

Rapid-scan time-resolved FT-IR spectroelectrochemistry studies on the electrochemical redox process

The electron transfer to or from molecules containing multiple redox centers has been extensively investigated. Rapid scan time-resolved FT-IR-RAS spectroelectrochemistry was used to investigate the electron-transfer mechanism in this report. The electron transfer of two typical compounds, 1,4-benzoquinone and 1,4-bis(2-ferrocenylvinyl)benzene, was examined with this method. Although the two compounds show two-electron transfer in the redox process, 1,4-benzoquinone exhibits two single electron waves while 1,4-bis(2-ferrocenylvinyl)benzene exhibits a single wave in cyclic voltammetric experiments. The IR absorption of the intermediate, BQ*- and p-(Fc-CH=CH)+2-benzene, at 1506 and 1589 cm(-1), respectively, appeared and disappeared on the experimental time scale in the oxidation and reduction process was observed. In the oxidation process of the p-(Fc-CH=CH)2-benzene molecule, one Fc was oxidated to Fc+ first and the electron-withdrawing ability of Fc+ was stronger than that of Fc, which resulted in the D-pi-A structure and the band at 1589 cm(-1) becoming visible. Then as the oxidation continues, the other Fc was oxidated to Fc+ too, which resulted in the reforming of the symmetry of the benzene ring A-pi-A, so the band at 1589 cm(-1) disappeared. Similar phenomenon can be elucidated in the reduction process but the configuration type changed from A-pi-A to D-pi-A and finally to D-pi-D. Hence, not only 1,4-benzoquinone but also 1,4-bis(2-ferrocenylvinyl)benzene show two consecutive one-electron processes. In addition, it is observed that the existing time of the electrochemical reaction intermediate (BQ*- and p-(Fc-CH=CH)+2-benzene) is prolonged at low temperatures due to slow reaction kinetics.     

Etude de composés d'addition d'acides de Lewis,XXXIV [1] Composés d'addition de benzoquinone-1, 4 avec TiCl4

The adduct 1,4-benzoquine · TiCl₄ has been prepared in CH₂Cl₂ solution at about ?60°. Its IR. spectrum has been recorded at the same temperature. The experimental study of the vibrational frequencies has been completed by the calculation of the fundamental vibrations in the molecular plane, using Wilson's FG method, with slightly simplified models of 1,4-benzoquinone · TiCl₄ (13 masses) and 1,4-benzoquinone · 2 TiCl₄ (14 masses); analysis by use of internal and symmetry coordinates. An assignment of most of the observed bands is proposed and the conclusion is reached that the complex, when solid, is (1,4-benzoquinone · TiCl₄)_n. The force constants F(C? O) are 9,85 · 10⁵ dyne/cm for the quinone and 8,8 · 10⁵ dyne/cm for the disturbed carbonyl bond of the polymerized complex in the model proposed. At ordinary temperature in benzene solution of the components the adduct 1,4-benzoquinone. TiCl₄ · benzene precipitated; with the help of the models, the fundamental vibrations of its IR. spectrum have been assigned.     

Construction of substituted benzene rings by palladium-catalyzed direct cross-coupling of olefins: a rapid synthetic route to 1,4-naphthoquinone and its derivatives

Ring the changes: The direct cross-coupling of electron-deficient 1,4-benzoquinone or its derivatives with electron-rich alkyl vinyl ethers proceeds in a tandem manner to produce substituted benzene rings with good selectivity and in good to excellent yields. The reaction has the potential for the rapid synthesis of diverse substituted benzene rings as it is not limited by substituent effects.     

Synthetic Approach Towards Hexaprismane. A Novel Entry to Homosecohexaprismane Skeleton by Cage Enlargement

A series of caged 1,4-diols, 26, 29a/29b, 31 , were synthesized from the Diels-Alder cycloadduct 21 of 1,2,3,4-tetrachloro-5,5-dimethoxycyclopentadiene and 1,4-benzoquinone. Reduction of enedione 21 with aqueous TiCl₃, followed by base-catalyzed enolization in the presence of acetic anhydride, gave diene 23b , which reacted with maleic anhydride and 1,4-benzoquinone to produce the corresponding [4+2] cycloadducts 24b and 27 , respectively. The adduct 24b was converted to birdcaged 1,4-diol 26 by photocyclization followed by decarboxylative olefination of resulted caged anhydride 25b . The adduct 27 was photocyclized to cage compound 28 , which was aromatized to dihydroquinone 29a by acid-catalyzed enolization, or benzo-annulated compound 31 by reduction and dehydration. The birdcaged 1,4-diols 26 and 31 underwent fragmentation induced by (diacetoxyiodo)benzene to give enediones 38/39 and 41/42 , respectively. Photocyclization of 38 and 39 produced the corresponding caged compounds 43 and 44 , respectively, possessing homosecohexaprismane skeletons. The corresponding monohydrate 43a of 43 was structurally characterized by single-crystal X-ray diffraction.     

Kinetics and mechanism of photolysis of 2,6-di-tert-butyl-1,4-benzoquinone diazide in benzene and deuterobenzene

Conclusions It has been established by kinetic and spectral methods that the cyclohexadiene carbene generated in the photolysis of 2,6-di-tert-butyl-1,4-benzoquinone diazide in benzene predominantly in the singlet state reacts with benzene to form a norcaradiene derivative, which isomerizes thermally to 4-phenylcyclohexadiene-2,5-one. The latter is converted thermally to 2,6-di-tert-butyl-4-phenylphenol.Translated from Izvestiya Akadeinii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2680–2685, December, 1986.     

Spectrophotometric assay of yeast vitality using 2,3,5,6-tetramethyl-1,4-benzoquinone and tetrazolium salts.

A method for the spectrophotometric assay of yeast vitality was developed using 2,3,5,6-tetramethyl-1,4-benzoquinone and tetrazolium salts. The metabolic efficiency of 2,3,5,6-tetramethyl-1,4-benzoquinone by yeast cells was used as an index of yeast vitality. 2,3,5,6-Tetramethyl-1,4-benzoquinone was reduced to 2,3,5,6-tetramethyl-1,4-hydroquinone by yeast cells. Then, the superoxide anion radicals generated from O2 by reduction with 2,3,5,6-tetramethyl-1,4-hydroquinone under alkaline conditions reduced tetrazolium salts to formazan, which exhibited absorbance maxima at 440 nm. A linear relationship between the absorbance and viable cell density was obtained in the range of 1.0 x 10(5)-2.0 x 10(7) cells/ml for a sample solution. During the cultivation of yeast cells, the absorbance showed almost an anti-parallel change with that of glucose in yeast growth and fermentation, suggesting that the absorbance change reflected the vitality of yeast cells.     

光控化学振荡器的设计(英文)

This article reviewed recent progresses in the design of a new class of chemical oscillators and developed a generic model that could qualitatively reproduce those photochemical oscillations seen in experiments. The two oscillators discussed in this report are based on the photolysis of 1,4-benzoquinone and its derivatives, in which external illumination is vital in initiating and sustaining the reaction processes. Nonlinear behavior in these two photo-controlled chemical oscillators are analyzed as a function of light intensity and the initial concentration of reagents including 1,4-benzoquinone, 1,4-hydroquinone, 2-methyl-1,4-benzoquinone, bromate, and sulfuric acid. A generic model proposed initially for the uncatalyzed bromate-aromatic compound reactions was modified here to account for the photolysis of 1,4-benzoquinone or 2-methyl-1,4-benzoquinone. The modified model qualitatively reproduced chemical oscillations and their dependence on light intensity.     

Eine einfache Synthese chiraler Arylbenzochinone und Arylbenzohydrochinone; Versucheines NMR.-Nachweises von Chiralität in isopropylsubstituierten Benzalanilinen

Atropisomeric diphenyls (V and VI) are easily prepared by the acid catalysed condensation of 2-methoxycarbonyl-1,4-benzoquinone and 2-acetyl-1,4-benzoquinone and trimethyl-1,4-benzoquinone respectively with 2-isopropyl-5-methylanisole and 2-isopropyl-3,5dimethylanisole. The reaction is not affected by steric hindrance; the more highly substituted phenols gave better yields. One of the diphenylderivatives has been resolved with help of dehydroabietylamine. Thermodynamic data for the racemisation process have been determined by classical polarimetric techniques (Table 4). The chirality of most of the compounds prepared is easily detected by considering the signals of the diastereotopic isopropyl group in the NMR.-spectrum. Probably because of solvent interaction NMR. kinetics have failed to give information about the racemisation process. Isopropyl-substituted benzal-anilines have been prepared. They did not show any ‘splitting’ of the isopropyl-groups in the NMR.     

Microwave-mediated Claisen rearrangement followed by phenol oxidation: a simple route to naturally occurring 1,4-benzoquinones. The first syntheses of verapliquinones A and B and panicein A

The naturally occurring 1,4-benzoquinones 2-methoxy-6-propyl-1,4-benzoquinone (1), 2-methoxy-6-pentyl-1,4-benzoquinone (primin 2), 2-methoxy-6-pentadecyl-1,4-benzoquinone (3), 2-methoxy-6-heptadecyl-1,4-benzoquinone (dihydroirisquinone, pallasone B; 4) were synthesized by a simple protocol involving microwave accelerated Claisen rearrangement of allyl ethers 10, followed by hydrogenation of the side chain alkene, and oxidation to the quinone. The Claisen-based methodology was extended to the first synthesis of the marine benzoquinones verapliquinones A and B (5 and 6), and panicein A (7). Isoarnebifuranone (9) was also synthesized by a similar strategy.     

Halogenation of N-substituted p-quinone imines and p-quinone oxime esters: IV. Chlorination and bromination of N-arylsulfonyl-2(3)-methyl(2-chloro)-1,4-benzoquinone monoimines

The addition of halogens to N-arylsulfonyl-1,4-benzoquinone imines, which exist in a solution as Z and E isomers, is controlled by the steric factor. Z-E Isomerization strongly affects the stability of cyclohexene structures formed by halogenation of 1,4-benzoquinone imines. The halogenation of N-arylsulfonyl-1,4-benzoquinone imines was found to be accompanied by prototropic rearrangement.