Ruthenium(II) Arene Complexes Bearing Tris(pyrazolyl)methanesulfonate Capping Ligands.Electrochemistry, Spectroscopic, and X-ray Structural Characterization

Novel [Ru(L)(Tpms)]Cl and [Ru(L)(Tpms(Ph))]Cl complexes (L = p-cymene, benzene, or hexamethylbenzene, Tpms = tris(pyrazolyl)-methanesulfonate, Tpms(Ph) = tris(3-phenylpyrazoly)methanesulfonate) have been prepared by reaction of [Ru(L)(mu-Cl)(2)](2) with Li[Tpms] and Li[Tpms(Ph)], respectively. [Ru(p-cymene)(Tpms)]BF4 has been synthesized through a metathetic reaction of [Ru(p-cymene)(Tpms)]Cl with AgBF4. [RuCl(cod)(Tpms)] (cod = 1,5-cyclooctadiene) and [RuCl(cod)(Tpms(Ph))] are also reported, being obtained by reaction of [RuCl2(cod)(MeCN)(2)] with Li[Tpms] and Li[Tpms(Ph)], respectively. The structures of the complexes and the coordination modes of the ligands have been established by IR, NMR, and single-crystal X-ray diffraction (for [RuL(Tpms)]X (L = p-cymene or HMB, X = Cl; L = p-cymene, X = BF4)) studies. Electrochemical studies showed that each complex undergoes a single-electron R-II -> R-III oxidation at a potential measured by cyclic voltammetry, allowing to compare the electron-donor characters of the tris(pyrazolyl)methanesulfonate and arene ligands, and to estimate, for the first time, the values of the Lever E-L ligand parameter for Tmps(Ph), HMB, and cod

Evidence of an association between poly(3-hydroxybutyrate) accumulation and phosphotransbutyrylase expression in Bacillus megaterium

Molecular analysis of a genomic region of Bacillus megaterium, a polyhydroxybutyrate (PHB)- producing microorganism, revealed the presence of a gene coding for the enzyme phosphotransbutyrylase (Ptb). Enzyme activity was measured throughout the different growth phases of B. megaterium and was found to correlate with PHB accumulation during the late-exponential growth phase. Ptb expression was repressed by glucose and activated by the branched amino acids isoleucine and valine. Overexpression of ActBm, a σ 54 regulator from B. megaterium whose gene is located upstream from ptb, caused an increase in Ptb activity and PHB accumulation in B. megaterium

Statistical optimization of a culture medium for biomass and poly(3-hydroxybutyrate) production by a recombinant Escherichia coli strain using agroindustrial byproducts

A statistically based Plackett-Burman screening design identified milk whey and corn steep liquor concentrations as well as ionic strength (based on phosphate buffer concentration) as the three main independent components of the culture medium that significantly (p < 0.05) influenced biomass and poly(3-hydroxybutyrate) (PHB) production in recombinant cells of Escherichia coli. This strain carries a plasmid encoding phb genes from a natural isolate of Azotobacte sp. Response surface methodology, using a central composite rotatable design, demonstrated that the optimal concentrations of the three components, defined as those yielding maximal biomass and PHB production in shaken flasks, were 37.96 g deproteinated milk whey powder/l, 29.39 g corn steep liquor/l, and 23.76 g phosphates/l (r2 = 0.957). The model was validated by culturing the recombinant cells in medium containing these optimal concentrations, which yielded 9.41 g biomass/l and 6.12 g PHB/l in the culture broth. Similar amounts of PHB were obtained following batch fermentations in a bioreactor. These results show that PHB can be produced efficiently by culturing the recombinant strain in medium containing cheap carbon and nitrogen sources. [Int Microbiol 2005; 8(4):243-250

Diseño de una guía de prácticas de laboratorio de acuerdo con las orientaciones del EEES

La adaptación de la docencia universitaria al Espacio Europeo de Educación Superior (EEES) supone un cambio en los sistemas de enseñanza actual. En este sentido el desarrollo de guías de laboratorio capaces de informar al alumnado, y normalizar la confección y presentación de las prácticas de laboratorio, asegurando una mejor calidad de la docencia y coordinación entre grupos, viene a cumplir con algunos de los objetivos pretendidos en el contexto de la Convergencia Europea. La Guía que se presenta, destinada a su empleo en la docencia práctica de una asignatura troncal de la licenciatura en Farmacia en la Universidad de Granada, recoge las indicaciones necesarias para llevar a cabo un trabajo seguro y eficiente en los laboratorios

Effect of polyphenolic compounds on the proteolytic activities of constitutive and immuno-proteasomes

The effect of several polyphenols on the 20S proteasomes, both the constitutive and the LMP proteasomes, isolated from bovine tissues, has been investigated. Polyphenolic compounds show many biological activities such as antiviral, antibacterial, antifungal, anti-inflammatory, antimutagenic, and antiallergic activities. However, the molecular mechanism underlying these effects has not been identified. It is well established that polyphenols possess inhibitory activities on several enzymes and among them the 20S proteasome. In the present work, the ChT-L, BrAAP, PGPH, and T-L activities of the isolated constitutive and immuno-proteasomes were assayed in order to get an overall information on the polyphenols binding to the complexes. The effects of the polyphenols on the proteasomal activities were analyzed, taking into account the different subunits composition of the two complexes. Furthermore the same activities were measured on whole extracts from cancer cells exposed to EGCG and gallic acid, evaluating, also, their antioxidant action under oxidative stress. EGCG and gallic acid are able to affect the 20S proteasomes functionality, depending on the complex subunit composition and, in cell extracts, they behave both as antioxidants and proteasome effectors

20S proteasome mediated degradation of DHFR: implications in neurodegenerative disorders

The 20S proteasome is responsible for the degradation of protein substrates implicated in the onset and progression of neurodegenerative disorders, such as a-synuclein and tau protein. Here we show that the 20S proteasome isolated from bovine brain directly hydrolyzes, in vitro, the dihydrofolate reductase (DHFR), demonstrated to be involved in the pathogenesis of neurodegenerative diseases. Furthermore, the DHFR susceptibility to proteolysis is enhanced by oxidative conditions induced by peroxynitrite, mimicking the oxidative environment typical of these disorders. The results obtained suggest that the folate metabolism may be impaired by an increased degradation of DHFR, mediated by the 20S proteasome

Chemical behavior and in vitro activity of mixed phosphine gold(I)compounds on melanoma cell lines.

7partially_openCARUSO F; PETTINARI C; PADUANO F; VILLA R; MARCHETTI F; E. MONTI; ROSSI MCaruso, F; Pettinari, C; Paduano, F; Villa, R; Marchetti, F; Monti, ELENA CATERINA; Rossi, M

A New Quantitative Classification of the Extrahepatic Biliary Tract Related to Cystic Duct Implantation

Background: Knowledge regarding biliary anatomy and its variations, including the cystic duct (CD), is important in the pre-surgical setting and for predicting biliary diseases. However, no large series has focused on CD evaluation using a quantitative analysis. The primary aim of this prospective study was to create a ‘taxonomic’ classification of CD anatomy in a large cohort of subjects who underwent magnetic resonance cholangiopancreatography (MRCP). The secondary aim was to evaluate the correlations between extrahepatic bile duct (EHBD) variants and biliary diseases. Methods: We enrolled patients who underwent MRCP for different clinical indications from January 2017 to May 2019. Demographical, anatomical and clinical data were evaluated using statistical analyses, as appropriate. The anatomical assessment of EHBD was performed using the standard classification for CD in low, medium, and high insertions, and the lengths of CD to the duodenal papilla (DP), and EHBD was determined to conduct a new quantitative analysis. Results: The final study population comprised 1004 subjects. A new classification for EHBD as per the percentile distribution of the ratio CDDP/EHBD was designed, and the following categories were obtained: type 1 (below the 25th percentile) for CDDP/EHBD ratio ≤ 50%; type 2 (25th to 75th percentile) for CDDP/EHBD ratio 51–75% and type 3 (above the 75th percentiles) for CDDP/EHBD ratio &gt; 75%. Type 1 of the new classification of CD implantation was significantly superior in terms of the detection of low, medial and intra-pancreatic CD that was significantly correlated with a high risk of choledochal lithiasis in comparison with the standard classification (P &lt; 0.001). Conclusions: The new classification of CD implantation enables identification of the vast majority of intra-pancreatic CDs that are correlated with a high risk of choledochal lithiasis in a single category (type 1) that is easy to identify using imaging