Volume 12, No. 2 (2011)
Articles
INNOVATIONS IN THE SYNTHESIS AND CHARACTERIZATION OF ELECTRO-OPTICAL MATERIALS BASED ON POLYMERS WITH CARBAZOLIC SEQUENCES<br/>DES NOUVEAUTES DANS LA SYNTHESE ET CARACTERISATION DES MATERIAUX ELECTRO OPTIQUES A BASES DES POLYMERES AVEC DES SEQUENCES CARBAZOLEIQUE
IONICA IONITA(1*), ANA-MARIA ALBU(2, 3), CRISTIANA RADULESCU(1), ELENA IRINA MOATER(1)
We live in a complex world where revolutionary progress has been and continues to be made in communications, computer memory, and data processing. There is a growing need for new technologies that rapidly detect and treat diseases at an early stage or even pre-stage. As we are accustomed to these advances, our expectations will demand more compact, energy-efficient, rapidly responding, and environmentally safe technologies. Since the discovery of the photorefractive effect in organic polymers, carbazole-containing polymers have also attracted much attention because of their photoconductivity. In this context, multicomponent polymers with structural units containing both photoconductive and electro-optic functionalities in the side chain can be regarded as potentially suitable materials for photorefractive applications. Azobenzene photochemistry is a fascinating area of investigation, on one hand, because it is fairly well known, and on the other hand, because it has produced and continues to reveal completely unexpected phenomena, some of them still unexplained. When the azobenzene group is incorporated into a polymer, its photoisomerization can have a wide range of unexpected possible consequences. Connecting the carbazole sequence with azo sequence, using en spacer with electrons, can enhance the electro-optical properties of the polymer materials based on carbazole. That can be realized first by (co)polymerization of the monomers with the azo-carbazole sequences. Secondly, the chemical transformations of the polymers contented by (co)polymerization of the known monomers with the carbazole monomers will be used. In these ideas the goal of this paper is an investigation of the scientifically literature regarding the new electro-active materials, peculiarly photorefractive alongside of our results in this field.
NEW ORGANOTIN (IV) FORMIATO ADDUCTS. <br/> SYNTHESIS AND SPECTROSCOPIC STUDIES
SEYDI MANSOUR SY SECK(1), LIBASSE DIOP(1*), LORENZO STIEVANO(2)
Five new formiato complexes have been synthesized and studied by spectroscopic methods. The structures, when the cations are involved through hydrogen bonds, are supramolecular. The anion behaves as a monocoordinating ligand. The existence of tetrahedral SnBu2(HCO2)2 has been evidenced in this work.
A NEW ROUTE FOR THE SYNTHESIS OF 2‑AMINOPYRIDINES<br/> NOUVELLE VOIE DE SYNTHESE DES 2-AMINOPYRIDINES
ZAHIRA KIBOU(1), NAWEL CHEIKH(1), NOUREDDINE CHOUKCHOU-BRAHAM(1*), BACHIR MOSTEFA-KARA(1), MOHAMMED BENABDELLAH(1), DIDIER VILLEMIN(2)
The 2-aminopyridines constitute a very large class of nitrogen heterocycles, which have a great biological activity, such as the antibacterial, anti-inflammatory and analgesics activity, as well as the 2-amino-4-(4-chlorophenyl)-5-oxo-5,6,7,8-tetrahydroquinoline-3-carbonitrile has a antifungal activity. A new approach of synthesis of 2 amino-3-cyanopyridines was developed in our laboratory, based on the condensation of the intermediary of enaminonitrile with different primary amines in solvent-free environments.
Cu(II) AND Zn(II) COMPLEX COMPOUNDS WITH BIGUANIDES AROMATIC DERIVATIVES. SYNTHESIS, CHARACTERIZATION, BIOLOGICAL ACTIVITY
TICUŢA NEGREANU-PÎRJOL(1*), BOGDAN NEGREANU-PÎRJOL(1), MIRELA CĂLINESCU(2), FLORINA DUMITRU(3), RODICA SÎRBU(1), RAMONA STOICESCU(1), GHASSOUB RIMA(4), CORNELIA GURAN(3)
In this paper we report the synthesis, physical-chemical characterization and antimicrobial activity of some new complex compounds of hetero-aromatic biguanides ligands, chlorhexidine base (CHX) and chlorhexidine diacetate (CHXac2) with metallic ions Cu(II) and Zn(II), in different molar ratio. The synthesized complexes were characterized by elemental chemical analysis and differential thermal analysis. The stereochemistry of the metallic ions was determined by infrared spectra, UV-Vis, EPR spectroscopy and magnetic susceptibility in the aim to establish the complexes structures. The biological activity of the new complex compounds was identified in solid technique by measuring minimum inhibition diameter of bacterial and fungal culture, against three standard pathogen strains, Escherichia coli ATCC 25922, Staphilococcus aureus ATCC 25923 and Candida albicans ATCC 10231. The results show an increased specific antimicrobial activity for the complexes chlorhexidine:Cu(II) 1:1 and 1:2 compared with the one of the Zn(II) complexes.
FACTS REGARDING THE PHARMACOGNOSTIC AND PHYTOCHEMICAL STUDY OF THE PLANT Parietaria Lusitanica L
MARIANA ARCUŞ(1*), GABRIELA LILIOS(1), TICUŢA NEGREANU-PÎRJOL(1), AGRIPINA ZAHARIA(2)
Specialized literature studies show that the species from the gender Parietaria have therapeutic usage in traditional medicine, which have diuretic, depurative, emollient, antitussive, antirheumatic, cholagogue, pectoral and laxative properties. In human medicine the aerial part of the plant is used externally for treating hemorrhoids and anal fissures. In this respect a pharmacognostic and phytochemical study of the species Parietaria lusitanica L. was initiated, species frequently used by the inhabitants from around Toulouse, France.
BIOMEDICAL MATERIALS BASED ON FULLERENES
RADU CLAUDIU FIERASCU(1, 2*), IRINA DUMITRIU(1, 2), RODICA MARIANA ION(1, 2), RALUCA IOANA BUNGHEZ(1, 2), MONICA NEAGU(3), CAROLINA CONSTANTIN(3), CRINA STAVARU(4)
Fullerenic soluble derivatives are essential for many biomedical techniques that exploit the chemical and physical properties of these unique structural carbon nanospheres. Their toxicity, demonstrated in vitro and in vivo is important for the characterization and the limitation of these applications. The photo toxicity of some fullerene molecules has been identified as a future therapeutic tool. The specific objective of the study is the synthesis of C60 derivatives. Starting from the characteristics of fullerene compounds, we tried to study in vitro C60 fullerene and some functionalized derivatives (C60 complexes with poly-vinyl pyrrolidone (PVP) and with the oxo-dimer (Fe-O)2TPP), experimental models in vitro with normal and tumor cells and investigation of their toxicological profile, in order to identify novel anti-neoplasic therapeutic devices.
EVALUATION OF HEAVY METALS CONTENT IN EDIBLE MUSHROOMS BY MICROWAVE DIGESTION AND FLAME ATOMIC ABSORPTION SPECTROMETRY<br/>DÉTERMINATION DES METAUX LOURDS DANS LES CHAMPIGNONS PAR DIGESTION ASSISTÉE PAR MICRO-ONDES ET SPECTROMÉTRIE D’ABSORPTION ATOMIQUE AVEC ATOMISATION PAR FLAMME
CRISTIANA RADULESCU(1*), CLAUDIA STIHI(1), VALERICA GH. CIMPOCA(1, 2), ION V. POPESCU(1, 2, 3), GABRIELA BUSUIOC(4), ANA IRINA GHEBOIANU(2)
The aim of this work was to determine the heavy metal (Cd, Cr, Ni, Pb, Mn, Zn, Fe and Cu) content of the fruiting bodies (cap and stipe) of four species (Amanita caesarea, Pleurotus ostreatus, Fistulina hepatica and Armillariella mellea) and their substrate, collected from forest sites in Dâmboviţa County, Romania. The elements were determined by Flame Atomic Absorption Spectrometry (FAAS) after microwave assisted digestion. From the same collecting point were taken n = 5 samples of young and mature fruiting bodies of mushrooms and their substrate. The high concentrations of lead, chrome and cadmium (Pb: 0.25 – 1.89 mg.kg-1, Cr: 0.36 – 1.94 mg.kg-1, Cd: 0.23 – 1.13 mg.kg-1) for all collected wild edible mushrooms, were determined. These data were compared with maximum level for certain contaminants in foodstuffs established by the commission of the European Committees (EC No 466/2001). A quantitative evaluation of the relationship of element uptake by mushrooms from substrate was made by calculating the accumulation coefficient (Ka). The moderately acid pH value of soil influenced the accumulation of Zn and Cd inside of the studied species. The variation of heavy metals content between edible mushrooms species is dependent upon the ability of the species to extract elements from the substrate and on the selective uptake and deposition of metals in tissue.
QUALITY CONTROL OF Scomber Scombrus (MACKEREL) MARKET IN ROMANIA
SIMONA DOBRINAS(*1), GABRIELA STANCIU(1), ALINA SOCEANU(1), DANUT TIBERIU EPURE(2), VALENTINA BOLD(1)
Different types of Scomber Scombrus (mackerel) available on the Romanian market (frozen, smoked, oil canned) have been analyzed, in order to highlight the differences in chemical composition between foods obtained using different preservation methods. For this, water content, total acidity, NaCl content, ammonium, total nitrogen and eight essential and/or potentially toxic elements (Cu, Cd, Fe, Mn, Zn, Pb, Cr, and Mg) were determined in five types of mackerel commercial products. The analyses were completed with sensorial analysis, and qualitative identification of antiseptic preservatives (hydrogen sulfide, formaldehyde and benzoic acid) has been performed. Hydrogen sulfide was not detected in any of the products studied, but benzoic acid and formaldehyde were detected in frozen and canned mackerel samples. The highest concentrations of essential elements were observed in frozen mackerel muscles, except iron (the highest value was found in canned mackerel). It can be concluded that concentrations of many essential elements decreased in the fish muscle due to smoking and sterilization. This study showed that the analyzed mackerel samples contain potentially toxic elements at levels without health risks.
PHYSICAL-CHEMICAL CHARACTERIZATION OF SOME GREEN AND RED MACROPHYTE ALGAE FROM THE ROMANIAN BLACK SEA LITTORAL
BOGDAN NEGREANU-PÎRJOL(1), TICUŢA NEGREANU-PÎRJOL(1*), GABRIELA PARASCHIV(2), MIHAELA BRATU1, RODICA SÎRBU(1), FLORENTINA RONCEA(1), AURELIA MEGHEA(3)
Algae are a group of organisms, Thallophytes, containing specific bioactive compounds (i.e. brominated phenols, heterocyclic oxygen compounds, sterols, terpenes, polysaccharides). Their excessive growth has negative consequences on marine organisms; on the other hand, they have a crucial role in food, pharmaceuticals, cosmetics, agriculture. In this paper were studied the main physical-chemical characteristics correlated with the biological specificity of three species of multicellular algae, Enteromorpha intestinalis and Ulva rigida (green), Ceramium rubrum (red), frequently encountered along the Romanian Black Sea coast. Generally mixtures of thallophytes algae from the Black Sea were collected, processed and characterized. Density, pH, conductivity, anions, loss on drying, ash, total nitrogen, protein, lipids, carbohydrates, carotenoids were determined. The results emphasized the possibility of using these marine resources as biofertilizer in agriculture.
THE EFFECT OF TRANSGLUTAMINASE ON THE RHEOLOGICAL PROPERTIES OF YOGURT
IULIANA APRODU(1*), GABRIELA GURAU(2), AURELIA IONESCU(1), IULIANA BANU(1)
The aim of this study was to investigate the rheological characteristics of yogurts obtained from milk treated with transglutaminase prior to fermentation with Streptococus theromophilus and Lactobacillus delbrueckii subsp. Bulgaricus. A set of 36 experiments were carried out to test the influence of various enzyme concentrations ranging from 0 to 0.04%, different setting temperatures (35, 40 and 45 oC), and setting time (60, 90 and 120 min). The cross-linking of milk proteins influenced the post-acidification process as well as the stability of the yogurt samples. The enzymatic treatment of milk allowed avoiding the syneresis phenomena during yogurt storage at 4 oC; the water holding capacity during centrifugation was also improved. Concerning the rheological properties, the apparent viscosity of yogurt increased by increasing the enzyme concentration and the setting time for the entire tested domain of shear rates. The results indicate that transglutaminase catalyzed cross-linking is an effective tool for improving functional properties of yogurt.
THE EFFECT OF SOME TECHNOLOGICAL FACTORS ON THE RYE SOURDOUGH BREAD
IULIANA BANU(*), INA VASILEAN (SIMITARU), VASILICA BARBU, CATALIN IANCU
The modern biotechnology of bread production uses sourdough as a natural leavening agent. In rye bread making the sourdough is essential. The aim of this paper was to examine the influence of starter culture types, flour extraction rate, dough yield and temperature of fermentation on the quality of the sourdough rye bread. The sourdough was prepared using a mixed culture of Lactobacillus plantarum and Lactobacillus brevis. The rye breads prepared with 20% sourdough and bread with no sourdough were investigated. The addition of sourdough increases the loaf specific volume relative to control sample. The best results were obtained in case of sourdough made from dark rye flour, 300 dough yield, after 24 h fermentation at 30 °C. The porosity of the bread was estimated by analyzing the scanned images of the vertically halved bread. Digital image analysis revealed that the cell-to-total area ratio was lower for the sourdough prepared with whole rye bread.
Me<sub>4</sub>NSO<sub>4</sub>SnI<sub>3</sub>: SYNTHESIS AND INFRARED STUDY
AMINATA DIASSÉ-SARR, LIBASSE DIOP(*)
Allowing (Me4N)2SO42H2O to react with SnI4, yields Me4NSO4SnI3. Its IR study allowed suggesting an infinite chain structure, the environment around the Sn(I)V center being trigonal bipyramidal.