High pressure studies on bis(l-histidinate)nickel(II) monohydrate.

Raman spectra of bis(l-histidinate)nickel(II) monohydrate crystal were obtained for pressures up to 9.5GPa. Our results show the disappearance of some of the Raman modes and the appearance of other modes. These modifications evidence that the sample undergoes phase transitions at around 0.8 and 3.2GPa. The role played by the Ni ions and hydrogen bonds in the dynamics of the phase transitions is discussed. Under decompression, down to atmospheric pressure, the original Raman spectra are recovered, showing that both phase transitions are fully reversible.

Pressure induced transformations in sorbic acid.

This research reports a pressure dependent Raman study of the sorbic acid between 0.0 and 10.0GPa. The unpolarized Raman spectra were measured in the spectral range of 20-3000cm-1. The high-pressure Raman scattering study of the sorbic acid showed that it underwent a gradual, disordering process. At the room temperature and at the ambient pressure conditions, the crystal structure of the sorbic acid belongs to the monoclinic system with a C2/c (C2h6) space group. The pressure increase induced a higher disorder in the monoclinic unit cell, since a single bending mode, and only very broad stretching Raman modes are present at pressure of ~10GPa. Upon pressure release the high-pressure phase transforms directly into the ambient-pressure phase. The presence of the internal vibrational modes is a guarantee that the molecular structure is maintained. Beyond this, the presence of external modes shows that the crystal has a memory to reverse the process and suggest that the crystal, which was in high disorder (broad Raman bands), does not suffer decomposition in the crystalline structure. The DFT calculations for the sorbic acid were performed in order to understand the vibrational properties. The theoretical study showed that the volume of the unit cell and beta angle decrease significatively when passing from the 0.0GPa to 8.0GPa. The decreases in the volume and beta angle of this particular unit cell were supposed to induce the larger increase in the bandwidths of the observed bands, pointing to some disorder in the monoclinic phase.

Efeito hipolipemiante da suplementação dietética com a farinha do cubiu (Solanum sessiliflorum Dunal) em ratos hipercolesterolêmicos / Hypolipidemic effect of diet supplementation with cocona (Solanum sessiliflorum Dunal) flour in hypercholesterolemic rats

Estudos com frutas e vegetais ricos em fibra alimentar tem demonstrado efeito redutor das concentrações sanguíneas de colesterol total, atuando de forma preventiva contra a hipercolesterolemia. O objetivo do presente trabalho foi analisar a composição química da farinha de cubiu e avaliar o efeito de seu consumo sobre a lipemia de ratos hipercolesterolêmicos. Foram utilizados 8 animais para cada tratamento, em 7 grupos sendo: 1 controle; 3 experimentais com 5%, 25% e 50% da recomendação de fibras (AIN-93) provenientes da farinha de cubiu; e 3 grupos per feeding tendo celulose e pectina como fonte de fibra alimentar nas mesmas proporções dos grupos experimentais. Ao final do ensaio foi verificado que não houve variação significativa no consumo de ração pelos animais e no ganho de massa corporal no decorrer do experimento. Os tratamentos com farinha de cubiu reduziram as concentrações de colesterol total (-21,6%), LDL-c (-56,8%), aumentaram a excreção de colesterol fecal (+116%), e diminuíram o colesterol hepático (-32,1%). Nenhum dos tratamentos promoveu alteração significativa nas concentrações de triglicerídeos. Os tratamentos com pectina e celulose demonstraram resultados semelhantes aos do cubiu. Os resultados observados servem como base para futuros estudos visando o aproveitamento biotecnológico deste fruto.

Studies with fruit and vegetables rich in dietary fiber have shown lowering effects on the blood concentrations of total cholesterol (TC), acting preventively against hypercholesterolemia. The aim of this study was to analyze the chemical composition of cocona and evaluate the effect of the consumption of cocona flour on lipemia of Wistar rats with hypercholesterolemia. Eight animals were used for each treatment, in 7 groups: control; 3 experimental groups with 5%, 25% and 50% of the recommended fiber (AIN-93) from cocona flour; 3 groups per feeding with pectin and cellulose as source of dietary fiber, in the same proportions of the experimental groups. At the end of the assay, we verified that there were not significant variations in the consumption of the animals and the body weight during the experiment. Treatments with cocna flour were responsible for reducing the concentrations of total cholesterol (-21.6%), LDL-c (-56.8%), increasing the excretion of fecal cholesterol (+116%) and lowering the liver cholesterol (-32.1%). None of the treatments significantly altered the triglyceride concentrations. Treatments using pectin and cellulose show results similar to cocona. The observed results can be used in further studies aimed at the biotechnological exploitation of this fruit.

The synthesis and characterisation of Sn(IV) complexes of 2,6-pyridine dicarboxylate--the molecular structure of divinyltin(IV) derivative.

A series of organotin(IV) derivatives were obtained employing 2,6-pyridinedicarboxylate as ligand: [{SnBu3(OOC)2C5H3N}n] (1), [SnBuCl(OOC)2C5H3N] (2) and [Sn(CHCH2)2(OOC)2C5H3N] (3). They were fully characterised by multinuclear NMR [1H, 13C{1H}, and 119Sn{1H}], IR spectroscopies and elemental analysis. In addition suitable crystals of (3) have shown a dimmeric arrangement by X-ray crystallographic studies, held together by Sn-O intermolecular interactions which persists in solution. The crystal packing shows hydrogen bonds joining the dimmers, forming two infinite one-dimensional chain. Each monomer comprises a Sn(IV) centre bonded to a pyridinecarboxylate-containing ring, through both nitrogen and oxygen donor atoms. It is also co-ordinated by a water molecule and two vinyl groups.

Efeito de diferentes doses de rutina sobre lipídeos no soro de coelhos machos e fêmeas / Different doses of the flavonoid rutin on the levels of serum lipids in male and female rabbits

O presente trabalho teve como objetivo avaliar o efeito de diferentes doses do flavonóide rutina sobre os níveis de lipídios no soro de coelhos machos e fêmeas da raça Nova Zelândia, com 55 dias de vida. De acordo com os resultados, o colesterol não diferiu estatisticamente nos machos, mas apresentou reduções significativas para as fêmeas. Com relação ao colesterol-HDL, as fêmeas não apresentaram alteraçõe e machos apresentaram reduções no grupo tratado 20mg/dia de rutina. Para triacilgliceróis, observou-se diferenças significativas nos grupos tratados com 60mg/dia de rutina.