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101.
V. I. Petrov A. A. Ozerov M. S. Novikov C. Pannecouque J. Balzarini E. De Clercq 《Chemistry of Heterocyclic Compounds》2003,39(9):1218-1226
New 9-(aryloxyalkyl) derivatives of adenine have been prepared by alkylation of adenine with tosylates, bromides, and -chloro ethers containing terminal aromatic fragments in anhydrous DMF in the presence of potassium carbonate. The compounds of the 9-(2-phenoxyethyl)adenine series appear to be highly reactive against cytomegaloviruses of mankind in vitro, while derivatives of 9-(2-benzyloxyethyl)adenine demonstrate anti-HIV-1 activity. Compounds with shorter or longer chains, and also compounds which do not have aromatic fragments at the ends of the chains, do not possess antiviral activity. 相似文献
102.
The radicals and anions derived from the 9H tautomer of adenine by adding a hydrogen atom to one of the four double bonds of the adenine framework have been studied. Computations were carried out using a carefully calibrated density functional (B3LYP) method and basis set (DZP++). Optimized geometries, energies, and vibrational frequencies are predicted for eight radicals and anions. The radicals are found to lie in a range of 22 kcal mol(-1), with the radical derived by addition to the C(8) carbon atom being the lowest lying energetically. The anions are predicted to be bound species in the gas phase with an energetic range of 43 kcal mol(-1). Anions produced by addition of a hydride ion to adenine carbon atoms are found to be the most favorable. Six of the anions are predicted to be stable species with respect to electron detachment. The adiabatic electron affinities, vertical electron affinities, and vertical detachment energies are computed for the first time. Electron affinities for these radicals range from 0.0 to 2.0 eV. Radicals produced by addition to a nitrogen atom have near-zero adiabatic electron affinities, while radicals produced by addition at carbon atoms have considerably higher electron affinities. 相似文献
103.
Sevgi Bayari Celal Bayrak Ziya Kantarci 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):23-35
IR spectra of Mn(adenine)2M(CN)4.C6H6 (M=Cd or Hg), andIR and Raman spectra of Cd(adenine)2M(CN)4.C6H6(M=Cd or Hg) are reported. The spectral data suggest thatthe host frameworks of these compounds are similarto those of the Hofmann-Td-type and the adeninecoordination is via N(10). 相似文献
104.
Catherine M HalliwellEvelyne Simon Chee-Seng TohPhilip N Bartlett Anthony E.G Cass 《Analytica chimica acta》2002,453(2):191-200
The immobilisation of enzymes on an electrode surface, in such a manner that they retain both substrate specificity and high levels of catalytic activity, is of great importance in bioelectrochemistry. This includes areas such as the development of enzyme-catalysed fuel cell electrodes, biosensors and other biotechnological applications. We have investigated the catalytic activity of hexahistidine tagged variants of lactate dehydrogenase (EC 1.1.1.27) from the thermophile Bacillus stearothermophilus both in solution and when immobilised on poly(aniline)-poly(acrylate) (PANi-PAA) or poly(aniline)-poly(vinyl sulphonate) (PANi-PVS) composite films. Both the C- and N-terminally tagged enzymes are readily immobilised on the modified electrode and catalyse the conversion of lactate and NAD+ to pyruvate and NADH. The NADH that is generated can be readily oxidised at the PANi-modified electrode surface.In solution, the activity of the C-tagged enzyme (LDH-CHis) was some 30% less that of the wild-type under comparable conditions, whereas the N-tagged enzyme was found to possess essentially the same activity as the wild-type. However, when the enzymes were immobilised on PANi-PAA and PANi-PVS the C-tagged enzyme films showed a higher NADH-dependent current than the wild-type LDH whilst the N-tagged enzyme had the highest of the three. In addition, the C-tagged enzyme film appeared more stable than the wild-type LDH-PANi film. A novel immobilisation chemistry of the enzyme is proposed to account for these observations. 相似文献
105.
Antimony(III) complexes with nitrogen-containing ligands: 2SbF3·Gly, SbF3·Gly, SbF3·2NA, SbFO·Gly, MSb2F7 (M=Et2NH2, Bu4N, HNA+), MSbF4 (M=Et2NH2, Pr2NH2, Bu4N, HNA+, HGly+), M2SbF5 (M=Et2NH2 and Pr2NH2), where Gly is glycine (+NH3CH2COO−) and NA is nicotinamide (β-C5H4NCONH2), were studied by121,123Sb NQR spectroscopy at 77 K.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2232–2236, November, 1998. 相似文献
106.
咖啡酸玻碳修饰电极对烟酰胺腺嘌呤二核苷酸的电催化氧化 总被引:1,自引:0,他引:1
研究了咖啡酸修饰电极的制备、性质及对NADH的电催化作用。修饰电极在0.1mol/L PBS缓冲溶液中(pH7.0)于0.0~ 050V(vs.Ag/AgCl)电位范围内呈现一对氧化还原峰,式量电位(E^0‘‘)为 0.250V(vs.Ag/AgCl)。E^0‘‘随pH增加而朝负方向移动,pH在5.0~8.0范围内,其线性回归方程为E^0‘‘=0.6233-0.05996pH,R=0.9969。表观电极反应速率常数(Kb)为12.3s^-1。电极反应的电子数为2且有2个质子参与。该修饰电极对NADH的氧化具有很好的电催化作用。NADH浓度在0.1—6.0mmol/L.范围内与峰电流呈现良好的线性关系。文中对电催化过程进行了探讨。 相似文献
107.
利用化学键合的方法,将合成的以四甲基四乙烯基环四硅氧烷(D4vi)为核的聚碳硅烷类有机硅树枝状大分子涂敷到毛细管电泳柱的内壁,并用其来分离碱基及其衍生物。由于树枝状大分子球状立体,能够在毛细管内壁形成一层牢固、具有一定厚度的涂层,该涂层能有效抑制碱性物质的吸附,显著提高分离柱效,柱效达到3.80×104plates/m;树枝状大分子的骨架为硅碳键,性能稳定,耐酸碱,形成涂层牢固,迁移时间重现性能良好。实验进一步讨论了涂敷次数对分离效果的影响,结果表明,二次涂敷的分离效果最好,分离柱效达到14.79×104plates/m。 相似文献
108.
A new method for the determination of lactic acid based on the immobilization enzyme fluorescence capillary analysis (IE-FCA) was proposed. Lactic dehydrogenase (LDH) was immobilized on inner surface of a capillary with glutaraldehyde, and an immobilized enzyme lactate capillary bioreactor (IE-LCBR) was formed for the determination of lactic acid. After nicotinamide adenine dinucleotide (NAD+) is mixed with lactic acid solution, it was sucked into the IE-LCBR and was detected at λex 353 nm/λem 466 nm. Optimized conditions are as follows: the temperature is 38 °C; the reaction time is 15 min; the concentrations of Tris buffer (pH 8.8) and NAD+ are 0.1 mol L−1 and 4 mmol L−1, respectively; the concentration of LDH used for immobilization is 15 kU L−1. The concentration of lactic acid is directly proportional to the fluorescence intensity measured from 0.50 to 2.0 mmol L−1; and the analytical recovery of added lactic acid was 99–105%. The minimum detection limit of the method is 0.40 mmol L−1 and sensitivity of the IE-CBR is 4.6 F mmol−1 L−1 lactate. Its relative standard deviation (R.S.D.) is ≤2.0%. This IE-FCA method was employed for determination of lactate in milk drink. 相似文献
109.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(5):571-583
Adenosine diphosphate (ADP) plays a crucial role in cell biochemistry, especially in metabolic pathways and energy storage. ADP itself, as well as many of its analogues, such as adenosine hypodiphosphate (AhDP), has been studied extensively, in particular in terms of enzymatic activity. However, structural studies in the solid state, especially for AhDP, are still missing. An analogue of ADP, i.e. adenosine hypodiphosphate ester, has been synthesized and characterized in the crystalline form as two hydrated sodium salts of 2′:3′‐isopropylideneadenosine 5′‐hypodiphosphate (H3AhDP, C13H19N5O9P2 for the neutral form), namely pentasodium tetrakis(2′:3′‐isopropylideneadenosine 5′‐hypodiphosphate) tetracosahydrate, 5Na+·3C13H18N5O9P2−·C13H17N5O9P22−·24H2O or Na5(H2AhDP)3(HAhDP)·24H2O, (I), and sodium tetrakis(2′:3′‐isopropylideneadenosine 5′‐hypodiphosphate) pentadecahydrate, Na+·C13H20N5O9P2+·2C13H18N5O9P2−·C13H19N5O9P2·15H2O or Na(H4AhDP)(H3AhDP)(H2AhDP)2·15H2O, (II). Crystal structure analyses of (I) and (II) reveal two nucleoside hypodiphosphate ions in the asymmetric units with different ionization states of the hypodiphosphate unit and adenine base. For all AhDP nucleotides, the same anti conformation about the N‐glycosidic bond and similar puckering of the ribose ring have been found. AhDP geometry and interactions have been compared to ADP nucleotides deposited in the Cambridge Structural Database. The adenine–hypodiphosphate interactions, identified as defining nucleotide self‐assembly, have been analysed in model systems, i.e. the adenine (Ade) salts of hypodiphosphoric acid, namely bis(adeninium) hypodiphosphate dihydrate, 2C5H6N5+·H2P2O62−·2H2O or (AdeH)2(H2P2O6)·2H2O, (III), and bis(adeninium) hypodiphosphate, 2C5H6N5+·H2P2O62− or (AdeH)2(H2P2O6), (IV). 相似文献
110.
《Electroanalysis》2018,30(2):238-249
A copper nano particles and cerium (IV) oxide modified carbon nanotube based composite on glassy carbon electrode (Cu−CeO2/MWCNT/GCE) was fabricated for simultaneous determination of guanine and adenine. The surface morphology, chemistry and conductance of the prepared electrodes were characterized by scanning electron microscopy (SEM), energy dispersion X‐ray (EDX), X‐Ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The Cu−CeO2/MWCNT/GCE improved electrochemical behaviour of guanine and adenine compared to other electrodes. The modified electrode was also used for individual and simultaneous determination of guanine and adenine. Under optimized conditions, the calibration curves were obtained linearly in the range of 0.20 to 6.00 μM for the guanine and 0.10 to 8.0 μM for the adenine by differential pulse voltammetry. The limits of detection of guanine and adenine were calculated as 0.128 and 0.062 μM, respectively. Interferences studies were also performed in the presence of inorganic and organic compounds. Moreover, the determination of guanine and adenine contents were carried out in a calf thymus DNA sample by the developed method with satisfactory results. 相似文献