FT‐IR,FT‐Raman,SERS spectra and computational calculations of 4‐ethyl‐N‐(2′‐hydroxy‐5′‐nitrophenyl)benzamide

Fourier transform infrared (FT‐IR) and FT‐Raman spectra of 4‐ethyl‐N‐(2′‐hydroxy‐5′‐nitrophenyl)benzamide were recorded and analyzed. A surface‐enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red shift of the NH stretching wavenumber in the infrared spectrum from the computational wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The simultaneous IR and Raman activation of the CO stretching mode gives the charge transfer interaction through a π‐conjugated path. The presence of methyl modes in the SERS spectrum indicates the nearness of the methyl group to the metal surface, which affects the orientation and metal molecule interaction. The first hyperpolarizability and predicted infrared intensities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive subject for future studies of nonlinear optics. Optimized geometrical parameters of the title compound are in agreement with reported structures. Copyright © 2009 John Wiley & Sons, Ltd.     

The biological effects of 632.8-nm low energy He-Ne laser on peripheral blood mononuclear cells in vitro

The aim of this study was to examine the proliferation of peripheral blood mononuclear cells due to the low energy 632.8-nm He-Ne laser application. The results of previous studies supported the hypothesis that low level laser therapy (LLLT) might have an increasing effect on the proliferation of lymphocytes and production of cytokines. The effect of laser irradiation was investigated by comparing the proliferation of peripheral blood mononuclear cells (PBMC) with a mitogenic stimulator, PHA (phytohemaglutinin) and laser irradiation. PBMCs of control samples, only laser irradiated samples, PHA included samples and both PHA included and laser irradiated samples were quantified and compared. Results of [3H] Thymidine test, 20 s laser irradiated and 40 s laser irradiated samples' proliferation were found statistically higher than control samples. There was no significant difference between control and 60 s laser irradiated samples. PHA also showed its ability to proliferate cells. PHA included samples and both PHA included and laser irradiated samples' proliferation was higher than both control and only laser irradiated samples. Our results showed that He-Ne laser application enhanced the proliferation significantly. Moreover, laser dose was noted as a significant parameter. On the other hand, LLLT by itself was found less effective than PHA.     

An intramolecular substitution of hydroperoxy-endoperoxide to a bis-endoperoxide

[reaction: see text] A new and stereospecific synthesis for bis-endoperoxide has been developed starting from tetrahydronaphthalene. Photooxygenation of tetrahydronaphthalene resulted in the formation of hydroperoxy-endoperoxide. The bromination reaction of hydroperoxy-endoperoxide gave bis-endoperoxide, whose exact configuration has been determined by X-ray analysis. The lowest-energy conformer of bis-endoperoxide is the boat-chair form.     

A Possible Relationship Between Serum Satellite DNA and Cellular Antioxidative Mechanism

The presence of circulating free DNA in the sera of cancer patients has been reported by different authors. Moreover, a hypothetical relationship between the DNA level and different stages of the disease has also been suggested. In this work, the free serum DNA level in various cancer patients was measured and consistent results with the reported data were found. (1,4) To assess the possible mechanism for the release of this fraction and to explain the high levels observed in cancer patients levels of the bivalent intracellularcation, magnesium were determined. Further to relate the process to the antioxidative mechanism of the cell membrane also selenium levels were measured simultaneously. The serum free DNA and the magnesium concentration of the patients before treatment were significally higher and the selenium levels lower than the control group. After appropriate the rapy the magnesium levels were found to decline while the high free DNA and low selenium values still persisted. These findings imply that the membrane stability and permeability is impaired due both to the neoplastic changes and later to the effect of chemotherapeutic agents with the result that intracellular material is released into the circulation.     

Newly synthesized Cu(II) pyrazino[2,3‐f][1,10]phenanthroline complexes as potential anticancer candidates

New binary and ternary copper(II) complexes, [Cu(py‐phen)₂(NO₃)]NO₃ ( 1 ), [Cu₂(py‐phen)₂(gly)₂(NO₃)₂(H₂O)₂]?3H₂O ( 2 ) and [Cu₂(py‐phen)₂(tyr)₂(H₂O)₂](NO₃)₂?3H₂O ( 3 ) (py‐phen: pyrazino[2,3‐f][1,10]phenanthroline; gly: glycine; tyr: tyrosine), have been synthesized and characterized using CHN analysis, electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy and single‐crystal X‐ray diffraction. Interaction of these complexes with calf thymus DNA has been investigated using absorption spectral titration, ethidium bromide and Hoechst 33258 displacement assay and thermal denaturation measurements. These complexes were found to be efficient cleaving agents and cleavage reactions were mediated by hydrolytic and oxidative pathways. The interaction between these complexes and bovine serum albumin (BSA) was investigated using electronic absorption and fluorescence spectroscopy. The experimental results show that the fluorescence quenching mechanism of these complexes and BSA is a static quenching process. Furthermore, in vitro cytotoxicities of these complexes against tumour cell lines (Caco‐2, MCF‐7 and A549) and healthy cell line (BEAS‐2B) showed that they exhibited anticancer activity with low IC₅₀ values. These complexes were markedly active against the cell lines and can be good drug candidates that are effective and safe for healthy tissue.     

Synthesis of tricyclic ring systems: [2+2] ketene addition reaction for preparation of tricyclic ketone,alcohol, and lactone derivatives

The addition of dichloroketene to 1,4-cyclohexadiene was examined. Dichloroketene, which was easily prepared from trichloroacetyl chloride and Zn–Cu, reacted with 1,4-cyclohexadiene in the presence of POCl₃ to afford novel racemic products of single addition (5) and double addition (6). The adducts 6 and 7 were reacted separately with MCPBA (meta-chloroperbenzoic acid), H₂O₂, LiAlH₄, and cis-diol 10 was reacted with PCC (pyridinium chlorochromate) to afford lactone, alcohol, and ketone derivatives likely to exhibit biological activity. The structures of all the racemic molecules mentioned in the article were determined from ¹H NMR, ¹³C NMR, MS, and IR data.     

Synthesis of New Tetrazole Derivatives of Spiro‐ and Bis‐barbiturates

This work described the synthesis of the first and unprecedented examples of 5‐aryl‐1H‐tetrazoles including spiro‐ and bis‐(thio)barbiturates, generated from the reaction between 4‐(1H‐tetrazol‐5‐yl)benzaldehyde with (thio)barbituric acids and cyanogen bromide (BrCN) in the presence of triethylamine, providing good overall yields. Tetrazoles based on bis‐(thio) barbiturates were also obtained in the absence of BrCN under the same conditions. The structures were characterized by IR, ¹H NMR, ¹³C NMR, X‐ray crystallography and mass analysis techniques. The reaction mechanism was proposed. The hydrogen bond strength (E_HB) versus d (O1?????O7 (w)) distance (kcal.mol^?1) and corresponding pKa value for the proton of H_3A (in water molecule) in 4b.H₂O were estimated to be 13.8 kcal.mol^?1 and 8.2, respectively.     

Synthesis and Characterization of Novel Aryl Cyclitols: Polycyclitols

New polycyclitols were synthesized starting from 1,4-naphthoquinone. An endo-selective Diels–Alder cycloaddition between 1,4-naphthoquinone and 1-acetoxybutadiene afforded a diketone. Reduction of the diketone with a NaBH₄-CeCl₃ · 7H₂O system gave a new cyclitol analog diol acetate. Acetylation of this compound afforded a triacetate. Oxidation of the double bond of the triacetate compound with OsO₄ followed by acetylation of hydroxyl groups gave the pentaacetate, whose structure was established unequivocally via application of x-ray crystallographic methods. Hydrolysis of ester groups of pentaacetate under basic condutions furnished the desired and another novel aryl cyclitol.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Fluctuations of spacetime and holographic noise in atomic interferometry

On small scales spacetime can be understood as some kind of spacetime foam of fluctuating bubbles or loops which are expected to be an outcome of a theory of quantum gravity. One recently discussed model for this kind of spacetime fluctuations is the holographic principle which allows to deduce the structure of these fluctuations. We review and discuss two scenarios which rely on the holographic principle leading to holographic noise. One scenario leads to fluctuations of the spacetime metric affecting the dynamics of quantum systems: (i) an apparent violation of the equivalence principle, (ii) a modification of the spreading of wave packets, and (iii) a loss of quantum coherence. All these effects can be tested with cold atoms.