Biomedical subjects

Anna Bellusci

Publications and source records attributed to Anna Bellusci.

6 recordsLinked to original sources

PubMed2006

A new synthesis of 2,3-dihydrobenzo[1,4]dioxine and 3,4-dihydro-2H-benzo[1,4]oxazine derivatives by tandem palladium-catalyzed oxidative aminocarbonylation-cyclization of 2-prop-2-ynyloxyphenols and 2-prop-2-ynyloxyanilines.

2-[(Dialkylcarbamoyl)methylene]-2,3-dihydrobenzo[1,4]dioxine and 3-[(dialkylcarbamoyl)methylene]-3,4-dihydro-2H-benzo[1,4]oxazine derivatives (3 and 5, respectively) were synthesized for the first time starting from readily available 2-prop-2-ynyloxyphenols 1 and 2-prop-2-ynyloxyanilines 4, respectively, through tandem oxidative aminocarbonylation of the triple bond-intramolecular conjugate addition. Reactions were carried out in the presence of catalytic amounts of PdI2 in conjunction with an excess of KI in N,N-dimethylacetamide (DMA) as the solvent at 80-100 degrees C and under 20 atm (at 25 degrees C) of a 4:1 mixture of CO-air. The reaction showed a significant degree of stereoselectivity, the Z isomers being formed preferentially or exclusively. The configuration around the double bond of the major stereoisomers was unequivocally established by X-ray diffraction analysis.

Aniline Compounds↗

PubMed2006

Silver coordination complexes as room-temperature multifunctional materials.

A series of bischelate ionic silver complexes [Ag(L*)(2)][X] was prepared by complexation of a newly synthesized 2,2'-bipyridine containing chiral alkoxy chains in the 4,4' positions. The appropriate choice of the construction motifs allows the preparation of new materials in which several functionalities can be introduced. Indeed, when the anion X(-) is a triflate or a dodecylsulfate group, the right combination of intermolecular interactions promotes the production of liquid crystalline mesophases. Therefore, the presence of coordinating anions, which drives the supramolecular assembly, is essential to generate, at the same time, room-temperature columnar hexagonal mesomorphism, the columnar helical supramolecular structure, and excimeric emission.

Journal Article↗

PubMed2006

Synthesis and anticancer activity of cyclopalladated complexes containing 4-hydroxy-acridine.

The synthesis and the characterization (elemental analysis, (1)H NMR and X-ray) of the first cyclopalladated complexes containing 4-hydroxyacridinate as complementary ligand are described. 4-Hydroxyacridine acts as a bidentate [N,O] chelating ligand, giving rise to square planar Pd(II) complexes in the coordination of a cyclopalladated fragment of phenylpyridine or phenylpyrimidine, characterized by the presence of two almost coplanar metalated rings. The biological activity studies conducted on these new Pd(II) complexes proved that the phenylpyridine Pd(II) derivative is more efficient than cis-platinum. The intrinsically substitutional inertness of the cyclopalladated ring and the presence of the [N,O] chelated acridine ligand make these systems of particular interest in their promising biological activity.

Acridines↗

PubMed2005

Synthesis and luminescent properties of novel lanthanide(III) beta-diketone complexes with nitrogen p,p'-disubstituted aromatic ligands.

Tris-beta-diketonate lanthanide(III) complexes (Ln = Eu, Er, Yb, Tb), of general formula [Ln(acac)3 L(m)], with chelating ligands such as 4,7-disubstituted-1,10-phenanthrolines and 4,4'-disubstituted-2,2'-bipyridines, have been synthesized and fully characterized. The inductive effects of the para-substituents on the aromatic N-donor ligands have been investigated both in the solid and in the solution states. Single-crystal X-ray structures have been determined for the diethyl 1,10-phenanthroline-4,7-dicarboxylate europium and 4,4'-dimethoxy-2,2'-bipyridine erbium derivatives, revealing a distorted square antiprismatic geometry around the lanthanide atom in both cases. The influence exerted by the p,p'-substituents with respect to the nitrogen coordinating atoms on the Ln-N bond distances is discussed comparing the geometrical parameters with those found for the crystal structures containing the fragments [Ln(III)(phen)] and [Ln(III)(bipy)] obtained from the Cambridge Structural Database. The influence exerted by the electron-attracting groups on the coordination ability of the ligands, that in some cases becomes lack of coordination of the lanthanide ions, has been also detected in solution where the loss of the ligand has been followed by UV-vis spectroscopy. Moreover, the use of relatively long alkoxy chains as substituents on the 1,10-phenanthroline ligand led to the formation of a promesogenic lanthanide complex, whose thermal behavior is encouraging for the synthesis of new lanthanide liquid-crystalline species.

Journal Article↗

PubMed2004

Pain-reduction strategies in hypnotic context and hypnosis: ERPs and SCRs during a secondary auditory task.

Pain-rating scores were obtained from 10 high, 10 medium, and 10 low hypnotizable subjects who were holding a painful cold bottle in their left hands and were exposed to pain reduction treatments while they were performing a secondary oddball task. All subjects received suggestions of dissociative imagery and focused analgesia as cognitive strategies for pain reduction. The following measures were obtained for tone targets of the auditory oddball task: (a) reaction time; (b) P300 peak amplitude of the event-related potentials; (c) skin conductance levels and skin conductance responses. Focused analgesia produced the most pain reduction in high, but not medium or low, hypnotizable subjects who showed shorter reaction times, higher central and parietal P300 peaks, and higher skin conductance responses. These findings were discussed vis-a-vis the dissociated-control model assuming that capacity demands of hypnotic suggestion are low.

Adult↗

PubMed1999

Pain perception, somatosensory event-related potentials and skin conductance responses to painful stimuli in high, mid, and low hypnotizable subjects: effects of differential pain reduction strategies.

In this study, pain perception, somatosensory event-related potential (SERP) and skin conductance response (SCR) changes during hypnotic suggestions of Deep Relaxation, Dissociated Imagery, Focused Analgesia, and Placebo, compared with a Waking baseline condition, were investigated. SERPs were recorded from frontal, temporal, central, and parietal scalp sites. Ten high, 9 mid, and 10 low hypnotizable right-handed women participated in the experiment. The following measures were obtained: (1) pain and distress tolerance ratings; (2) sensory and pain thresholds to biphasic electrical stimulation delivered to the right wrist; (3) reaction time and number of omitted responses; (4) N2 (280+/-11 ms) and P3 (405+/-19 ms) peak amplitudes of SERPs to target stimuli delivered using an odd-ball paradigm; (5) number of evoked SCRs and SCR amplitudes as a function of stimulus repetition. Results showed, high, mid and low hypnotizables exhibited significant reductions of reported pain and distress ratings during conditions of Deep Relaxation/Suggestion of Analgesia, Dissociated Imagery and Focused Analgesia. High hypnotizable subjects displayed significant reductions in pain and distress levels compared to mid and low hypnotizables during Dissociated Imagery, Focused Analgesia and, to a lesser degree, during Deep Relaxation. Placebo condition did not display significant differences among hypnotizability groups. High hypnotizables, compared to mid and low hypnotizables, also showed significant increases in sensory and pain thresholds during Dissociated Imagery and Focused Analgesia. High, mid, and low groups showed significant reductions in P3 peak amplitudes across all hypnosis conditions and, to a lesser degree, during Placebo. The temporal cortical region was the most sensitive in differentiating SERP responses among hypnotizability groups. On this recording area the subjects highly susceptible to hypnosis displayed significantly smaller P3 and greater N2 peaks during Focused Analgesia than did the other hypnotizable groups. In this condition highly susceptible subjects also reported the highest number of omitted responses and the shortest Reaction Times. These subjects also showed faster habituation of SCRs when compared with mid and low hypnotizables. During Dissociated Imagery and Focused Analgesia, highly hypnotizable subjects also disclosed a smaller total number of evoked SCRs than did mid and low hypnotizable subjects. The results are discussed considering possible common and different mechanisms to account for the effects of different hypnotic suggestions.

Analysis of Variance↗