用碳糊修饰电极测定氨基酸的伏安法研究：Ⅱ.组氨酸在氧化铝修饰碳糊 …

用１０％氧化铝的修饰碳糊电极研究了测定组氨酸的伏安法。在０．０５ｍｏｌ／Ｌ丁二酸－硼砂（ｐＨ＝３．５）底液中在－０．６Ｖ出现一还原峰,结合２．５次微分技术测定组氨酸,在３．２０～１３０μｍｏｌ／Ｌ浓度范围内有良好的线性关系,相对标准偏差为３．４％,检出限为０．４μｍｏｌ／Ｌ。检测灵敏度比文献报道有较大的提高。文中还讨论了电极过程。     

稀土金属尾式组氨酸卟啉配合物的合成及光电性质

合成了尾式氨基酸卟啉 5-(三苯甲基-组氨酸酰胺基苯基)-10,15,20-三苯基卟啉(1)的稀土金属配合物[Ln=Sm(2), Eu(3), Er(4), Dy(5), Yb(6)]. 通过紫外-可见光谱、 红外光谱、 元素分析及飞行时间质谱对稀土金属卟啉配合物进行了表征, 并研究了卟啉样品的荧光性质和表面光电压性质. 由于卟啉1周边存在吸电子基团, 致使其荧光发射强度和荧光量子产率较低; 稀土金属卟啉配合物3的荧光量子产率较高, 配合物6的荧光量子产率最低, 这主要是由稀土金属离子性质及无辐射跃迁强度不同造成的. 通过研究卟啉样品的表面光电压性质发现, 外加电场性质及外加电压强弱对光电压信号有较明显的影响, 这为氨基酸类金属卟啉化合物在光电器件方面的研究提供了一定的理论依据.     

组氨酸钴氧合反应的电喷雾串联质谱

组氨酸合钴配合物是重要的氧载体模型化合物,对揭示氧载体的可逆吸氧机理的研究有着重要的作用。本文以组氨酸合钴吸氧初和吸氧中期两个阶段为研究体系,采用电喷雾多级串联质谱技术对组氨酸合钴氧载体的质谱裂解规律进行了研究。在其质谱裂解图谱中发现了氧合配合物碎片峰,将该氧合配合物碎片峰进一步裂解,可得到失去中性氧分子的子离子碎片峰,从而对其氧合形式进行了确认,根据所得质谱数据对组氨酸合钴氧合产物的结构、裂解规律及氧气的存在形态给出合理的推论。结果表明,吸氧过程是一个动态的变化过程,组氨酸合钴配合物吸氧初和吸氧24h后,分子氧均以超氧型形式存在,但其型态经历了从双核超氧桥联配合物到双核双桥联超氧羟基配合物的转变。对此过程的研究一直缺乏直接测定方法未被完全确定。本文采用电喷雾多级串联质谱技术对此氧合反应的机理进行了探讨,并初步确立电喷雾质谱（ESI-MS）可做为研究氧合反应和表征氧合配合物的有效技术手段。     

A Study of the Electrochemistry of Two Biacridine Derivatives and Their Application

The electrochemlcal behavior of two new synthesized biacridine derivatives,3,3’－disulfonyl－9,9’－biacridine dinitrate（DSBADN）and 10,10’－dimethyl－3,3’－disulfonyl－9,9’－biacridine（DMDSBA）was investigated by means of cyclic voltammetry and linear sweep polarography．Ina HCl solution,the reduction peak current was proportional to the concentrations of DSBADNand DMDSBA．The electrochemical study demonstrated that the reduction peak currents ofDSBADN and DMDSBA exhibited adsorptive and diffusion－controlled characteristics,and the     

Templating core–shell particles using metal ion-chelating biosurfactants

Designer biosurfactants can be used to stabilise and functionalise interfaces. One particularly promising use is the stabilisation of oil-in-water emulsions, enabling fine tuning physical, chemical and biological surface properties. The ability of emulsion systems to carry high payloads makes them attractive for applications in medicine, food and fragrances, and cosmetics. However, they have limited long-term stability. Here we sought to use the metal ion-chelating ability of the biosurfactant peptide, AM1, to precipitate the formation of a gold metal shell on AM1-stabilised emulsions by electroless plating. We found that replacing the commonly used zinc(II) with palladium(II) for coordination by histidine residues of adjacent AM1 peptides produced interfacial films that maintained elasticity at acidic pH. Proton NMR suggested a coordination mechanism independent of the imidazole ring of the histidines. Nevertheless. stabilisation of emulsions at low pH enabled the deposition of a gold shell, albeit by an unexpected mechanism. We propose that gold nanoparticles forming in bulk are adsorbed onto the peptide-stabilised interface, accumulating into a particulate coating. The resulting one-step method for nanoparticle precipitation and shell formation will be useful for the creation of biocompatible core–shell particles for applications where large payloads of hydrophobic active compounds require stability over long time periods.     

Characterization of Adducts Formed in the Reactions of Methylglyoxal and Malonaldehyde with Lysine and Histidine Derivatives

Glycation of biopolymers by α‐oxoaldehydes such as methylglyoxal is believed to play a major role in the complex pathologies associated with diabetes and metabolic diseases. To design strategies that could interfere with the endogenous production of such aldehydes or promote their detoxification or, alternatively, to develop therapeutic procedures that could inhibit the deleterious effects of the oxoaldehydes at the cellular level, it is important to characterize the wide spectrum of reactions between these compounds and biomolecules, and gain insight into their mechanisms. In this study, we investigated the reactivity of endogenous α‐oxoaldehyde, methylglyoxal, and of malonaldehyde towards amino acid derivatives, and we identified new adducts with N^α‐acetyllysine and N^α‐acetylhistidine. In addition, we showed that a structurally analogous adduct is also formed with the model peptide N‐acetylglycyllysine O‐methyl ester. The characterized compounds were most likely derived from the addition of the appropriate nucleophilic center of the studied biomolecules to the C?C bond of the initially formed aldehyde conjugate. The resulted adducts contain an electrophilic β‐dicarbonyl moiety and could potentially be involved in the formation of DNA? protein or protein cross? links.     

α-氨基酸各官能团对其Co(Ⅱ)配合物可逆氧合性能的影响

选择氧合性能良好的组氨酸(His)-Co(Ⅱ)作为研究对象,分别掩蔽—NH2、取代—O-和去除—COO-,得到短肽、伪肽和多胺等类组氨酸结构.采用UV-Vis光谱法研究了α-氨基酸中的3个官能团对其Co(Ⅱ)配合物氧合性能的影响.对比研究表明:α-氨基酸中—NH2对其Co(Ⅱ)配合物的吸氧性具有决定作用;—COO-对其Co(Ⅱ)配合物氧合作用的可逆性起关键作用;而—O-对其Co(Ⅱ)配合物的吸氧性影响不大.在前期研究结果的基础上,对α-氨基酸-Co(Ⅱ)配合物可逆吸收和释放O2的机理进行了探讨.     

Examination of Correlation between Histidine and Cadmium Absorption by Eleagnus angustifolia L .,Vitisvinifera L . and Nerium oleander L .Using HPLC-MS and ICP-MS

In this study,HPLC-MS and ICP-MS methods wereused for the determination of histidine and cadmiumin Eleagnusangustifolia L.,Vitisvinifera L.and Nerium oleander L.leaves taken from industrial area including Gaziantep and Bursa cities.To histidine determination by HPLC-MS,flow rate of mobile phase,fragmentor potential,injection volume and column temperature were optimized as 0.2mL·min~(-1),70V,15μL and 20℃,respectively.For extraction of histidine from plants,distilled water was used by applying on 90℃and 30min.The concentrations(as mg·kg~(-1))of histidine were found to be in range of 8~22for Eleagnusangustifolia L.,10~33for Vitisvinifera L.and 6~11for Nerium oleander L.The concentrations of cadmium were found to be in ranges of 6~21μg·kg~(-1) for Vitisvinifera L.15~110μg·kg~(-1) for Eleagnusangustifolia L.and 63~218μg·kg~(-1) for Nerium oleander L.     

咪唑基引起缩合试剂3-(二乙氧基磷酰基)-氧-1,2,3-苯并三嗪-4(3H)-酮(DEPBT)的副反应

当用DEPBT作为缩合试剂合成含组氨酸的肌肽(β-Ala-His)衍生物时, 又偶然发现了另一个副反应. 在这个反应中, 没有得到预期的肌肽产物, 而是生成了一个结构与DEPBT相关的副产物EODhbt(3-乙氧基-3,4-二氢-1,2,3-苯并三嗪-4-酮). 本文报道了此副产物的发现、 结构鉴定及影响副反应的各种因素. 这对深入了解DEPBT的反应特性, 并且在含组氨酸的多肽合成中更有效地应用DEPBT提供了有用的信息.     

组氨酸/乳状液膜复合净化材料对甘油三酯的清除研究

依据甘油三酯在体内的代谢过程,将组氨酸作为模拟酶,与液体石蜡-Span 80乳状液膜体系复合,制备具有双重选择性的复合血液净化材料,并对其主要影响因素进行了研究.对三硬酯酸甘油酯的清除实验表明,该复合体系在30min内,即可有效清除目标物,表观清除率可达0.03.