The molecular structure of 2-N-ethylamino-5-methyl-4-nitropyridine (EN5MP) and its vibrational spectra have been analyzed in terms of quantum chemical DFT calculations (B3LYP/6-311++G(d,p) ...approaches) and related to the XRD data. The EN5MP crystal is triclinic and centrosymmetric and its unit-cell is built by asymmetric units consisting of two parallelly arranged formula units, 2C8H11N3O2, of different conformations. In each of the two subunits the methyl carbons and N-atoms of the nitro group are coplanar with the pyridine ring, but the O-atoms are inclined from this plane in the opposite directions. Dimers are linked by intermolecular NH⋯N hydrogen bonds system. Properties of the NAH⋯NP interactions between the hydrogen atom of the pyridine ring NP and the hydrogen atom of the amino group NA have been characterized. Additionally the crystal structure is stabilized by a set of weak intermolecular CH⋯O interactions.
Peritoneal metastases from colorectal cancer (CRCPM) are related to poor prognosis. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been reported to improve ...survival, but peritoneal recurrence rates are still high and there is no consensus on the drug of choice for HIPEC. The aim of this study was to use patient derived organoids (PDO) to build a relevant CRCPM model to improve HIPEC efficacy in a comprehensive bench-to-bedside strategy.
Oxaliplatin (L-OHP), cisplatin (CDDP), mitomycin-c (MMC) and doxorubicin (DOX) were used to mimic HIPEC on twelve PDO lines derived from twelve CRCPM patients, using clinically relevant concentrations. After chemotherapeutic interventions, cell viability was assessed with a luminescent assay, and the obtained dose-response curves were used to determine the half-maximal inhibitory concentrations. Also, induction of apoptosis by different HIPEC interventions on PDOs was studied by evaluating CASPASE3 cleavage.
Response to drug treatments varied considerably among PDOs. The two schemes with better response at clinically relevant concentrations included MMC alone or combined with CDDP. L-OHP showed relative efficacy only when administered at low concentrations over a long perfusion period. PDOs showed that the short course/high dose L-OHP scheme did not appear to be an effective choice for HIPEC in CRCPM. HIPEC administered under hyperthermia conditions enhanced the effect of chemotherapy drugs against cancer cells, affecting PDO viability and apoptosis. Finally, PDO co-cultured with cancer-associated fibroblast impacted HIPEC treatments by increasing PDO viability and reducing CASPASES activity.
Our study suggests that PDOs could be a reliable in vitro model to evaluate HIPEC schemes at individual-patient level and to develop more effective treatment strategies for CRCPM.
The copper phytate IP6Cu, IP6Cu
2
and IP6Cu
3
complexes were synthesized changing the phytate to metal mole ratio. The obtained products have been characterized by means of chemical and spectroscopic ...studies. Spectroscopic ATR/IR, FT-Raman, UV–Vis, EPR and magnetic measurements were carried out. The structures of these compounds have been proposed on the basis of the group theory and geometry optimization taking into account the shape and number of the bands corresponding to the stretching and bending vibrations of the phosphate group and metal–oxygen polyhedron. The role of the inter- and intra-hydrogen bonds in stabilization of the structure has been discussed. EPR studies showed that a local rhombic symmetry of copper ions appears in the studied phytates. Dominant interactions show antiferromagnetic properties depending on the content of paramagnetic ions.
The crystal and molecular structures of 6-methyl-3,5-dinitro-2-(E)-phenyldiazenylpyridine have been determined by X-ray diffraction and quantum chemical DFT calculations. The crystal is monoclinic, ...space group Cc (No. 9) with Z=4 with the unit cell parameters: a=12.083(7), b=12.881(6), c=8.134(3) Å and β=97.09(5)°. The azo-bridge appears in the trans conformation in which C2-N2-N2′-C1′ torsion angle takes a value −178.6(3)°, whereas the dihedral angle between the planes of the phenyl and pyridine rings is 3.5(2)°. The IR and Raman spectra measured in the temperature range 80–350K and quantum chemical calculations with the use of B3LYP/6-311G(2d,2p) approach confirmed the trans configuration of the azo-bridge as the most stable energetically and allowed determination of the energy other virtual structures. The observed effects were used in the discussion of vibrational dynamics of the studied compound. The energy gap between cis and trans conformers equals to 1.054eV (0.03873 Hartree). The electron absorption and emission spectra have been measured and analyzed on the basis of DFT calculations. The life time of the excited state is 12μs and the Stokes shift is close to 5470cm−1.
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•6-Methyl-3,5-dinitro-2-(E)-phenyldiazenylpyridine was synthesized.•The X-ray diffraction, UV–Vis and vibrational spectra were measured.•Their results were discussed in terms of quantum chemical calculations.
The crystal and molecular structure and physicochemical properties of 2-N-methylamino-3-methylpyridine N-oxide (MA3MPO) have been studied. MA3MPO was synthesized from 2-amino-3-methylpyridine by ...several steps to form colorless crystals suitable for crystallographic analysis. The data reveal that MA3MPO crystallizes in the monoclinic space group P21/n. The studied compound contains a nearly flat triply substituted pyridine skeleton whose structure is stabilized by an intramolecular N–H⋅⋅⋅O hydrogen bond. The N-oxide molecules are connected together by weak C–H⋯O hydrogen bonds, an acceptor of which is the oxygen atom from the N-oxide group. This leads to creation of two-dimensional network of hydrogen bonds. Its IR, Raman, UV–Vis and luminescence spectra have been measured and analyzed on the basis of DFT and NBO quantum chemical calculations in which the B3LYP/6-311++G(d,p) approach was applied. The distribution of the electron levels in the studied compound has been analyzed in terms of the possibility of its participation in the ligand-to-lanthanide ion energy transfer.
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•The 2-N-methylamino-3-methylpyridine N-oxide (MA3MPO) was synthesized and characterized.•The studied compound structure is stabilized by an intramolecular N–H⋯O hydrogen bond.•The molecules are connected together by weak C–H⋯O hydrogen bonds.•The amino group plays the role of effective hydrogen-bond donor but the N-oxide group is a hydrogen-bond acceptor.•X-ray, IR, Raman and DFT methods recognized the existence of the intramolecular N–H⋯O hydrogen bond in the studied compound.
Time-dependent changes of chicken meat were studied using Fourier transform IR and Raman techniques. Small pieces of intact chicken breast muscle (
pectoralis major
) were used in the investigations. ...They were stored in air at 22 °C up to 10 days and their IR and Raman spectra were measured successfully. Analysis of the obtained spectra was performed using a deconvolution of the experimental bands into Lorentz components. All integral intensities of the observed bands were standardized using the statistical R2 coefficient of determination. The R
2
values were automatically created as the output of the Origin software. The time-dependent changes of the spectra were used for meat spoilage detection. The analytical relationships between the integral intensities of selected bands have been derived indicating an increase of free amino acids content as the main effect of the chicken breast muscle spoilage.
IR and Raman spectra of Ca2MgSi2O7, Ca2ZnSi2O7 and Sr2MgSi2O7 oriented single crystals and powders have been measured. The temperature dependence of phonons has been established in the 4–650K range. ...Discussion of the results has been performed on the basis of factor group approach for the tetragonal P4̄21m (D2d3) space group with Z=2. The assignment of the bands observed to the internal and external modes has been made on their polarization behaviour, phonon energy calculations and literature data. The evidences of the LO–TO splitting and commensurate (C) to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. As a representative example, the results obtained for the spontaneous Raman scattering have also been used in the discussion of the stimulated Raman spectra of Ca2ZnSi2O7.
Raman and IR spectra of Ca2MgSi2O7, Ca2ZnSi2O7, Sr2MgSi2O7 have been measured. The temperature dependence of phonons has been established in the 4–650K range. The evidences of the LO-TO splitting and commensurate (C) to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. Display omitted
► Polarized IR and Raman spectra of pyrosilicates single crystals have been studied. ► Temperature dependence of the phonon bands and LO–TO splitting have been analysed. ► Commensurate to incommensurate and to normal phase have been evidenced in the spectra. ► Phonon calculations have been used in assignment of the normal modes. ► Stimulated Raman spectra of Ca2ZnSi2O7 crystal have been measured and analysed.
The electron absorption and emission spectra were measured for the pyramidal LnPc(OAc) complexes in the solid state and co-doped in silica glass, where Ln=Er, Eu and Ho. The theoretical electron ...spectra were determined from the quantum chemical DFT calculation using four approximations CAM-B3LYP/LANL2DZ, CAM-B3LYP/CC-PVDZ, B3LYP/LANL2DZ and B3LYP/CC-PVDZ. It was shown that the best agreement between the calculated and experimental structural parameters and spectroscopic data was reached for the CAM-B3LYP/LANL2DZ model. The emission spectra were measured using the excitations both in the ligand and lanthanide absorption ranges. The possibility of energy transfer between the phthalocyanine ligand and excited states of lanthanide ions was discussed. It was shown that the back energy transfer from metal states to phthalocyanine state is responsible for the observed emission of the studied complexes both in the polycrystalline state and silica glass.
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•Lanthanide(III) phthalocyanines of the LnPc(OAc) type were synthesized in the solid state.•Sol-gel glass doped with LnPc(OAc), Ln=Eu, Ho and Er, complexes was obtained.•The quantum chemical DFT calculations using four theoretical models have been done.•Luminescence of ligand is only visible.
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•Four azobipyridines were synthesized.•Based on the DFT modeling the structures of these compounds were proposed.•The vibrational characteristics of the azo-bond were reported.•The ...role of substitution position of the methyl group was discussed.
Syntheses of 3,3′-dinitro-2,2′-azobipyridine and 4,4′ (or 5,5′ or 6,6′)-dimethyl-3,3′-dinitro-2,2′-azobipyridine have been described. Molecular structures of these compounds have been determined and compared, to the basic compound, azobipyridine, reported by us earlier. The conformation of the azo-bond and other structural data are discussed in terms of substitution place of methyl chromophore. Fourier transform IR and Raman spectra of these compounds have been measured and analysed. The 6-311G (2d,2p) basis set with the B3LYP functional have been used to discuss the space conformation and dynamics of the studied compounds.
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