Publications

Abstract The anticancer (cytotoxicity against human mammary gland adenocarcinoma cells) and anti-inflammatory properties (COX-2 inhibition) of the hydroxycinnamic derivatives trans-3-(3,4,5-trihydroxyphenyl)-2-propenoic acid, trans-ethyl(3,4,5-trihydroxyphenyl)-2-propenoate and diethyl 2-(3,4,5-trihydroxy-phenylmethylene)malonate were screened. Data point out a putative correlation between anti-inflammatory and anticancer properties and suggest hydroxycinnamic derivatives as promising lead compounds for the development of anti-inflammatory/chemopreventive agents.

Abstract The co-administration of methamphetamine (METH) and MOR (MOR)-like compounds is becoming increasingly popular among drug abusers. Recently, it was demonstrated that rats would self-inject METH-heroin combination and that this combination produced a greater rewarding effect than the identical doses of METH alone and it was further suggested that enhanced reward might underlie the popularity of this combination. However, there is null information on the effects of the MOR-METH combination on striatal dopaminergic transmission. In the present article, in vivo brain microdialysis was used to examine the effects of two METH doses (1 and 5 mg/kg, i.p.; [METH1: hyperlocomotion-inducing] and [METH5: stereotypy-inducing], respectively) and MOR (10 mg/kg, i.p. [MOR10]) either alone or in combination on dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) release in caudate putamen (CPu) in freely moving rats. METH1 evoked a transient threefold increase in DA overflow in only one-third of dosed rats. On the contrary, METH5 elicited a 11-fold increase in the extracellular DA levels 30 min after dosing and stayed significantly (P < 0.05) above control levels up to 1.5 h. On the other hand, MOR10 did not significantly change DA extracellular levels. MOR10-METH1 combination prolonged DA outflow for 1 h in all rats dosed without changing peak effect compared to METH1. On the other hand, MOR10-METH5 combination did not change the peak effect nor the DA outflow profile compared to METH5 alone. Consistently, there is a concentration-dependent decrease in DOPAC efflux evoked by METH: METH1 evoked a smaller decrease in DOPAC outflow showing a tendency for returning to basal values whereas METH5 kept DOPAC extracellular levels reduced throughout the experiment. Again, MOR10 did not significantly change DOPAC extracellular levels. MOR delayed the onset without changing METH effect on the DOPAC output. These findings provide suggestive evidence that MOR potentiated the increase in extracellular DA levels induced by a low dose of METH. Thus, this combination yields a profile of action that might underlie the reinforcing properties sought by drug addicts.

Abstract A new electrically calibrated calorimetric system to measure heat capacities of solids has been designed and tested by determining the heat capacity of sapphire and benzoic acid in the temperature range 298-393 K. Comparison of the obtained results with recommended adiabatic calorimetry data showed that the maximum and average absolute deviations were 3.3% and 1.6%, respectively. The technique provides a convenient alternative to routine heat capacity determinations by DSC, since the experiments are faster and, in general, the results have better accuracy. In addition, the sample cells can be kept under argon or nitrogen atmosphere thus enabling the study of air sensitive compounds.

Abstract The gas-phase standard molar enthalpies of formation of the three monoiodoanilines were derived from the enthalpies of combustion in the condensed phases. measured by rotating-bomb calorimetry and their enthalpies of sublimation/vaporization obtained by Calvet microcalorimetry at T = 298.15 K. The standard enthalpies of formation for these compounds and for the diiodoaniline isomers were determined by DFT calculations. The theoretical calculations were performed with the B3LYP/6-31G(d):SBKJ-VDZ and B3LYP/6-311G(2d, 2p):SBKJ-VDZ approaches. Estimated values are in excellent agreement with the reported experimental numbers derived in the present Letter.

Abstract The enthalpies of combustion, heat capacities, enthalpies of sublimation and enthalpies of formation of 2-tert-butylbenzimidazole (2tBuBIM) and 2-phenylimidazole (2PhIM) are reported and the results compared with those of benzene derivatives and a series of azoles (imidazoles, pyrazoles, benzimidazoles and indazoles). Theoretical estimates of the enthalpies of formation were obtained through the use of atom equivalent schemes. The necessary energies were obtained in single-point calculations at the B3LYP/6-311++G(d,p) on B3LYP/6-31G* optimized geometries. The comparison of experimental and calculated values of all studied compounds bearing H (unsubstituted), methyl (Me) ethyl (Et), propyl (Pr), isopropyl (iPr), tert-butyl (tBu), benzyl (Bn) and phenyl (Ph) groups show remarkable homogeneity. The remarkable consistency of both the calculated and experimental results allows us to predict with reasonable certainty the missing experimental values. The crystal and molecular structure of the 2-benzylbenzimidazole (2BnBIM) has been determined by X-ray analysis. The observed molecular conformation permits the crystal being built up through N-H...N hydrogen bonds and van der Waals contacts between the molecules. An attempt has been made to relate the crystal structure to the enthalpies of sublimation.

Abstract The standard (p degrees = 0.1 MPa) molar energies of combustion in oxygen of N-(diethylaminothiocarbonyl)-N'-monoethylbenzamidine, PhCNHEtNCSNEt2 (DATMB), and N-(diethylaminothiocarbonyl)benzimido ethylester, PhCOEtNCSNEt2 (DATBE), were measured, at T = 298.15 K, by rotating-bomb calorimetry. The standard molar enthalpies of sublimation of these compounds were determined using Calvet microcalorimetry. These values were used to derive the standard molar enthalpies of formation of the title compounds, in their crystalline and gaseous phases, respectively. Compounds -Delta U-c degrees(m) (cr)/ -Delta H-f degrees(m)(cr)/ Delta H-g(cr)degrees(m)/ (kJ center dot mol(-1)) (kJ center dot mol(-1)) (kL center dot mol(-1)) N-(Diethylaminothiocarbonyl)-N'-monoethylbenzamidine (DATMB) 9053.6 +/- 3.9 45.7 +/- 4.4 141.2 +/- 1.2 N-(Diethylaminothiocarbonyl)benzimido ethylester (DATBE) 8780.9 +/- 4.0 176.2 +/- 4.4 135.6 +/- 2.6 The standard molar enthalpies of formation for the two title compounds, in the gaseous state, were also calculated based on density functional theory at the B3LYP/6-311++G(2dfp)//6-31+G(d,p)-level of theory, anchored on previous experimental data for the standard molar enthalpy of formation of N-(diethylaminothiocarbonyl)-benzamidine.