Flaviano Coletta

1H and 13C NMR studies of palladium(II) and platinum(II) complexation of cytosine

Abstract 1H and 13C NMR spectra of cytosine, cytosine hydrochloride, and the systems cytosine-PdCl2 and cytosine-PtCl2 in DMSO-d6 are reported. Analysis of the spectra shows that the 4-amino-2(1H)pyrimidinone structure of the ligand is retained upon metal complexation and the N-3 atom is the binding site.

13C-NMR Spectra of Some π-(Arene)-Tricarbonylchromium(O) Complexes

Abstract Many 13C-NMR studies dedicated to the π-(Arene)-tri-carbonylchromium(o) complexes are concerned with the origin of the large upfield shifts of the aromatic carbons on the coordination to the chromiumtricarbonyl group. This effect is not yet completely understood and various hypotheses have been formulated to justify it (1)(2)(3) (4).

Substituent Effects on the 13C-NMR Chemical Shifts of the Pyridinic Ring

Abstract The aryl substituent effects of the -N[dbnd]N-φ and -CH[dbnd]CH-φ groups and a simple additivity relationship have been used to calculate the 13C chemical shifts in the pyridine ring of symmetrical azopyridines, dipyri dilethylenes and styrilpyridines, and a good correlation has been found with the measured values.

A Comparative Study of Water T1 and T2 Nmr Relaxation Times in Healthy and Pathological Blood Fluid

Abstract Water protons T1 and T2 relaxation times in samples of whole blood, obtained from healthy people and from patients affected by Macrocytic Anemia on one side and Lymphatic and Myeloid Leukemia on the other, have been measured with the FT NMR technique at 80 Mhz and at 25 °C. No significant difference with respect to the value of the spin lattice relaxation time parameter measured for the healthy control group is experimentally evident in the case of the Macrocytic Anaemia while the spin spin relaxation time increases in magnitude. On the reverse both the leukemic cases present a significant (p < 0.001) increase in the relaxation times with respect to the control group. The experimental relaxation data belonging to the anaemic case show a linear correlation with the red cells volume while that obtained for the two leukaemic cases appear linearly correlated with the total white cell numbers. From the relaxation data an estimate of the amount of water tightly bound to the white cells membrane can be determined which results roughly thirty times lower than that bound to the red cells membrane. In this work is also presented a step by step outline of the water relaxation behavior which starts with the pure water and ends with the water in the whole blood supported by relaxation experiments done on the isolated blood main components.

Activation Energies for the Longitudinal Relaxation Rates of the Water in Normal and Neoplastic Lung

Abstract Variable temperature water T1 relaxation times have been measured on some normal and neoplastic human lung tissues. The corresponding activation energies have been derived and a short discussion of the experimental results is given.

Carbon-13 Spin-Lattice Relaxation and Noe of trans-Azobenzene and Symmetrical trans-Azopyridines

Abstract The 13C longitudinal relaxation times (T1) and the nuclear Overhauser effects (NOE) of trans-Azobenzene and symmetrical trans-Azopyrines show that the protonated carbon atoms relax essentially by a dipolar mechanism. The anisotropy of the motion suggests a rod like shape of these molecules in solution.

SYNTHESIS AND PHOTOCHEMICAL BEHAVIOUR OF α‐PHENYL‐3‐STYRYLPYRIDINE

WE HAVE recently illustrated the synthesis of some a-substituted 2and 4-styrylpyridines and some aspects of their photoreactions of geometrical isomerization and phenanthrenic cyclization [ 11. We have now extended the study to a-phenyl-3-styrylpyridine. The photochemistry of this compound appears to be very interesting; by U.V. irradiation, besides the cistrans photoisomerization, the formation of three different photocyclization products is expected, as illustrated in Fig. 1. The a-phenyl-3-styrylpyridine cannot be prepared by the method adopted for the corresponding 2and 4-styrylpyridines, i.e., by the Shaw [21 condensation of benzylpyridine and benzaldehyde, as the greater charge density in the meta than in the orrho and para position in the pyridine ring makes the proton detachment from the reactive

A STUDY OF WATER T1 AND T2 NMR RELAXATION TIMES IN HEALTHY AND CANCER AFFECTED HUMAN BLOOD PLASMA DOPED WITH HEMATOPORPHYRIN IX DYE

Human blood plasma water protons relaxation times T1 b and T2 b in the protein bound water phase restricted motion state have been determined for the native and hematoporphyrin IX (HMP) doped samples at the temperature of 20 °C and 1H NMR frequency of 80 Mhz. The samples belong to either healthy and myeloma affected patients. The resulting bound water relaxation times show a clear dependence from a single irrotational correlation time τc b, related to the relatively slow motion of the proteins present in solution. Noteworthy the values of the τc b s slow down in presence of the HMP dye and the effect is more marked in the myeloma blood plasma than in the healthy samples. This observation agrees with the measurements done previously with spectrofluorimetric techniques which show a specific interaction, time persistent, between the HMP and the fraction of the lipoproteins in plasma. The rationalization of the experimental data using the homonuclear magnetic dipolar interaction equations of Solomon-Bloembergen enables to point out that one proton of the water molecule is relaxed by two nearby protons, one of which belongs to one of the hydroxyethyl side chains of the HMP linked with a hydrogen bond to the probed water molecule and stable on the NMR timescale.

CINE - MR DETECTION OF GEOMETRICAL SIZE ANOMALIES IN THE DESCENDING CHEST AORTHIC ARTERY FOR SOME HEART PATHOLOGIES

Abstract In this MRI work the Fast Gradient-Echo technique has been applied to the detection of the geometrical and elastic properties of the chest aorthic descending artery to check probable troubles in the blood flux which subtend several heart pathologies. The average diameter and the time variations of the aorthic vessel have been measured in the axial scanning plane to minimize the experimental errors. From the analysis of the vessel average diameter and the related root mean square deviation, a parameter named Contractility has been defined, in close relation with the elastic properties of the aorthic vessel. This parameter measured in patients affected from heavy cardiac pathologies such as aorthic arc aneurysm and right atrial mixoma shows remarkable variations when compared to the values obtained in healthy subjects. The use of the Contractility is suggested for a quick MRI determination of these cardiocircolatory pathologies.

Frequency dependence of T1 and T2 relaxation times of water in normal and tumoral lung tissues. T2 relaxation time evidence of water different chemical shifts and exchange rates

Abstract Water 1H relaxation times, T1 and T2, have been measured at different magnetic fields for a total of 22 samples of normal and tumoral lung tissues taken away just after surgery. Results indicate that the average T1 values increase continuously with the inverse of the square root of the resonance frequency. The opposite trend is manifested for the average T2 values, which decrease continuously with the square of the frequency. We interpret the anomalous frequency dependence of T2 by introducing in the relationship a field dependent term. This term is indicative of the presence of a minimum of two kinds of water molecular surroundings in both normal and neoplastic lung tissues. The upper limits of the exchange rates are derived in this way. The values of these exchange rates are different for normal and neoplastic tissue.