Structure and luminescent investigation of the Ln(III)-beta-diketonate complexes containing tertiary amides

The synthesis and photoluminescent properties of Ln(III)-thenoyltrifluoroacetonate and dibenzoylmethanate complexes (Ln = Eu(III) and Gd(III) ions) containing tertiary amides such as dimethylacetamide (DMA), dimethylformamide (DMF), and dimethylbenzamide (DMB) as neutral ligands are reported. The Ln complexes were characterized by elemental analysis, complexometric titration with EDTA, and infrared spectroscopy. Single-crystal X-ray structure data of the [Eu(DBM)(3).(DMA)] compound indicates that this complex crystallizes in the triclinic system, space group PT with the following cell parameters: a = 10.2580(3) angstrom, b = 10.3843(2) angstrom, c= 22.3517(5) angstrom, alpha = 78.906(2)degrees, beta = 78.049(2)degrees, lambda= 63.239(2)degrees, V= 2066.41(9) angstrom(3), and Z = 2. The coordination polyhedron for the Eu(III) complex may be described as an approximate C-2v distorted monocapped trigonal prism. The optical properties of the Eu(III) complexes were studied based on the intensity parameters and luminescence quantum yield (q). The values of the ohm(2) parameter of the Eu-DBM complexes are larger than those for the Eu-TTA complexes, indicating that the Eu(III) ion is in a more polarizable chemical environment in the former case. The geometries of the complexes have been optimized by using the Sparkle Model, and the results have been used to perform theoretical predictions of the ligand-to-metal energy transfer via direct and exchange Coulomb mechanisms. (C) 2012 Elsevier Ltd. All rights reserved.

Investigação eletroquímica e calorimétrica da interação de novos agentes antitumorais biscatiônicos com DNA

Biscationic amidines bind in the DNA minor groove and present biological activity against a range of infectious diseases. Two new biscationic compounds (bis-α,ω-S-thioureido, amino and sulfide analogues) were synthesized in good yields and fully characterized, and their interaction with DNA was also investigated. Isothermal titration calorimetry (ITC) was used to measure the thermodynamic properties of binding interactions between DNA and these ligands. A double stranded calf thymus DNA immobilized on an electrode surface was used to study the possible DNA-interacting abilities of these compounds towards dsDNA in situ. A remarkable interaction of these compounds with DNA was demonstrated and their potential application as anticancer agents was furthered.

Evidence-based clinical use of insulin premixtures

Brazil is expected to have 19.6 million patients with diabetes by the year 2030. A key concept in the treatment of type 2 diabetes mellitus (T2DM) is establishing individualized glycemic goals based on each patient’s clinical characteristics, which impact the choice of antihyperglycemic therapy. Targets for glycemic control, including fasting blood glucose, postprandial blood glucose, and glycated hemoglobin (A1C), are often not reached solely with antihyperglycemic therapy, and insulin therapy is often required. Basal insulin is considered an initial strategy; however, premixed insulins are convenient and are equally or more effective, especially for patients who require both basal and prandial control but desire a more simplified strategy involving fewer daily injections than a basal-bolus regimen. Most physicians are reluctant to transition patients to insulin treatment due to inappropriate assumptions and insufficient information. We conducted a nonsystematic review in PubMed and identified the most relevant and recently published articles that compared the use of premixed insulin versus basal insulin analogues used alone or in combination with rapid-acting insulin analogues before meals in patients with T2DM. These studies suggest that premixed insulin analogues are equally or more effective in reducing A1C compared to basal insulin analogues alone in spite of the small increase in the risk of nonsevere hypoglycemic events and nonclinically significant weight gain. Premixed insulin analogues can be used in insulin-naïve patients, in patients already on basal insulin therapy, and those using basal-bolus therapy who are noncompliant with blood glucose self-monitoring and titration of multiple insulin doses. We additionally provide practical aspects related to titration for the specific premixed insulin analogue formulations commercially available in Brazil.