Quantitative Analysis of a Promising Cancer Biomarker,Calretinin, by a Biosensing System Based on Simple and Effective Immobilization Process

Calretinin (CAL) is calcium binding protein, and its levels in blood and cerebrospinal fluids are increased, since its expression is increased various cancer types. A novel biosensor system fabricated by immobilization of a specific antibody to CAL, anti‐Calretinin (anti‐CAL), onto a gold electrode surface via an effective covalent binding method using mercaptohexanol, epichlorohydrin, and ethanolamine was reported for the sensitive, selective, and accurate analysis of CAL. The proposed biosensor showed a linear calibration range between 1 ng/mL and 5 ng/mL. LOD and LOQ values were determined as 0.11 ng/mL and 0.38 ng/mL, respectively. The standard deviation related to the reproducibility of the new biosensor system was calculated as 3.95 %. Lastly, in order to state the applicability of the biosensor to early diagnosis of CAL in practice, artificial serum samples spiked with CAL have been analyzed by the proposed biosensor.     

Unexpected Cyclization of Dipyridyl-glycoluril in the Presence of Formaldehyde and Strong Acid: A New Scaffold with a Potential as an Anion Receptor

In an attempted synthesis of peripherally pyridine-substituted cucurbituril, an unexpected cyclized product was obtained. A careful NMR analysis followed by mass spectrometry and preliminary crystallographic analyses, helped us in resolving the structure. The structure has two quaternized pyridine functionalities and a groove suitable as a potential receptor site. In addition, just like the parent glycoluril structure, two remaining urea-derived nitrogens can be alkylated by alkyl halides. Thus, we believe this high yielding reaction may become an entry point to a new class of anion receptors.     

Ramanspektroskopische Untersuchungen an Seleninyldibromid

TheRaman spectra of solid and molten SeOBr₂ as well as of a CCl₄ solution have been recorded for the first time. The spectra indicate associated molecules in the molten state and relatively strong intermolecular interactions in the solid. Monomeric pyramidal molecules are present in the CCl₄ solution. An assignment will be discussed in analogy to SeOCl₂.

     

The structure of ethyl allyl 1,4-dihydro-2,6-dimethyl-4-[4-(4H-4-oxo-1-benzopyran-2-yl)phenyl]-3,5-pyridine dicarboxylate

The crystal and molecular structure of the title compound has been determined by direct methods, and refined to a finalR of 0.070 for 1466 observed reflections. The compound crystallizes in space group P2_l/n with cell dimensionsa=10.706(8),b=21.127(11),c=12.038(10) Å, Z=4.1,4-dihydropyridine ring adopts a boat shaped conformation. The flavon molecule is planar and it's phenyl ring is almost perpendicular to the 1,4-DHP. The C36 atom of the allyl group shows disorder.     

Candida zeylanoides as whole-cell biocatalyst to perform asymmetric bioreduction of benzophenone derivatives

Abstract

Candida zeylanoides P1 was investigated as whole cell biocatalyst for the bioreduction of biaryl prochiral ketones into chiral carbinols, which can be used as pharmaceutical intermediate. Bioreduction of different biaryl ketones was carried out to their corresponding chiral biaryl carbinols such as (S)-(4-chlorophenyl) (phenyl) methanol (2a), which can be used in the synthesis of L-cloperastine drug, with antitussive, antiepidemic activity and bronchial musculature relaxant characteristics, in gram scale, enantiopure form (>99%) and excellent yields. The selectivity of C. zeylanoides P1 in enantioselective reduction of biaryl ketones was not affected by the steric and electronic effects of substrates. The current method demonstrates an encouraging green chemistry approach for the production of biaryl secondary chiral alcohols of pharmaceutical importance in mild, inexpensive and environmentally friendly process. The present study has many benefits since this yeast biocatalyst were successfully applied bioreduction of structurally bulky prochiral substrates, which cannot be reducted by chemical catalysis.     

聚苯胺的质子酸掺杂机制的研究

木文用FT-IR、ESR、XPS等研究了聚苯胺的质子酸掺杂机制。结果表明聚苯胺掺杂时的质子化反应优先发生在分子链中的醌亚胺结构单元的氮原子上,并产生了分子内氧化还原反应而形成阳离子自由基。质子所带的电荷由于共轭作用能较好地离域到邻近苯环及对位氮原子上。     

Crystal Structure of N,N'-Bis(dodecyl)diaza- 18-crown-6 Complexed Sodium Perchlorate

The crystal structure of a new complex of a diaza-crown ether having two side arms has been determined from X-ray diffraction data. The compound crystallizes in space group P1 with cell dimensions a = 9.982(1), b = 10.685(1), c = 20.376(2)Å, = 81.09(1), = 80.92(1), = 88.43(1)0, Z = 2. The structure has been solved by direct methods and refined to the final R value of 0.053 for 3458 observed reflections and 424 parameters. The diaza-18-crown-6 ligand adopts an approximate D3d conformation. The Na+ ion is held inside the molecular cavity of this macroring ligand and a ClO-4 oxygen coordinates with Na+. The average Na–-O (18-crown-6) and Na–-N bond lengths are 2.426(4) and 2.786(5)Å, respectively; the Na–-O (ClO-4) bond length is 2.472(4)Å. The mean cavity radius is 1.10 Å and the NN nonbonding distance is 4.605(6)Å.     

A sensitive and selective ratiometric near IR fluorescent probe for zinc ions based on the distyryl-bodipy fluorophore

A novel distyryl-substituted boradiazaindacene (bodipy) dye with an emission peak moving hypsochromically from 730 to 680 nm on Zn(II) ion binding seems to be promising as one of the very few water-soluble fluorescent chemosensors emitting in the near IR region.     

Fiber optic pH sensing with long wavelength excitable Schiff bases in the pH range of 7.0-12.0

Most of the fluorescent pH probes work near neutral or acidic regions of the pH scale. In this work, two different fluorescent Schiff bases, chloro phenyl imino propenyl aniline (CPIPA) and nitro phenyl imino propenyl aniline (NPIPA), have been investigated for pH sensing in the alkaline region. Absorption and emission based spectral data, quantum yield, fluorescence lifetime, photostability and acidity constant (pK(a)) of the Schiff bases were determined in conventional solvents and in PVC. The long wavelength excitable immobilized Schiff bases CPIPA (lambda(ex)=556 nm) and NPIPA (lambda(ex)=570 nm) exhibited absorption and emission based optical response to proton in the pH range of 8.0-12.0 and 7.0-12.0, respectively. Response of the CPIPA was fully reversible within the dynamic working range. The response times were between 3-13 min. A relative signal change of 95% and 96% have been achieved for sensor dyes of CPIPA and NPIPA, respectively. The CPIPA displayed better fluorescence quantum yield (varphi(F)=3.7 x 10(-1)) and higher matrix compatibility compared to NPIPA (varphi(F)=1.6 x 10(-1)) in immobilized PVC. The CPIPA and NPIPA exhibited a slight cross sensitivity to the ions of Hg(+) and Fe(3+), respectively.     

Bis(2-pyridyl)-substituted boratriazaindacene as an NIR-emitting chemosensor for Hg(II)

Aryl-substituted boratriazaindacenes (Aza-Bodipy's) are a new class of dyes with long wavelength absorption and emissions. We now report the first application of these dyes in metal ion sensing. 2-Pyridyl substituents at positions 1 and 7 create a well-defined pocket for metal ion binding. The chemosensor described here is selective for Hg(II) ions, and both absorption and emission spectra display large changes that would allow ratiometric sensing. [reaction: see text].