Evaluation of the genetic variability of orchid fleck virus by single-strand conformational polymorphism analysis and nucleotide sequencing of a fragment from the nucleocapsid gene

The variability of a fragment of the nucleocapsid gene of orchid fleck virus (OFV) was investigated by single-strand conformational polymorphism (SSCP) analysis and nucleotide sequencing. Forty-eight samples of 18 genera of orchids were collected from Brazil, Costa Rica and Australia. The SSCP analysis yielded six different band patterns, and phylogenetic analysis based on the nucleotide fragment sequence obtained in this work and six available in GenBank showed two different groups, one with isolates 023Germany and So-Japan, and other with the rest of the isolates. None of the analyses showed geographic correlation among the Brazilian strains. The data obtained in this study showed a low genetic variation in this region of the genome; the d(N)/d(S) ratio of 0.251-0.405 demonstrated a negative selective pressure that maintains the stability of the analyzed fragments.

Chemical characterization, bioactive compounds, and antioxidant capacity of jussara (Euterpe edulis) fruit from the Atlantic Forest in southern Brazil

Samples of fruit from the jussara palm plant (Euterpe edulis), collected in different regions of the state of Santa Catarina. Brazil, were analyzed for chemical composition. phenolic acids. anthocyanins, flavonoids and fatty acids profile. Results indicated that the jussara fruit has a high lipid content (18.45-44.08%), oleic acid (44.17-55.61%) and linoleic acid (18.19-25.36%) are the fatty acids found in the highest proportion, and other components were proteins (5.13-8.21%). ash (1.55-3.32%) and moisture (34.95-42.47%). Significant differences were found in the total phenolic, total monomeric anthocyanins and other flavonoids for the samples from the five cultivation regions. The fruit from region E harvested in summer, with high temperatures and medium altitudes, had the highest contents of total phenolics (2610.86 +/- 3.89 mg 100 g(-1) GAE) and monomeric anthocyanins (1080.54 +/- 2.33 mg 100g(-1) cy-3-glu). The phenolic compound included ferulic, gallic, hydroxybenzoic and p-coumaric acids, as well as catechin, epicatechin and quercetin. The results show promising perspectives for the exploitation of this tropical fruit with a chemical composition comprising considerable phenolic acids and flavonoids compounds and showing activity antioxidant. (C) 2010 Published by Elsevier Ltd.

Cu and Fe metallic ions-mediated oxidation of low-density lipoproteins studied by NMR, TEM and Z-scan technique

In this work we report on a study of the morphological changes of LDL induced in vitro by metallic ions (Cu(2+) and Fe(3+)). These modifications were characterized by transmission electron microscopy, nuclear magnetic resonance and the Z-scan technique. The degree of oxidative modification of LDL was determined by the TBARS and lipid hydroperoxides assays. It is shown that distinct pathways for modifying lipoproteins lead to different morphological transformations of the particles characterized by changes in size and/or shape of the resulting particles, and by the tendency to induce aggregation of the particles. There were no evidence of melting of particles promoted by oxidative processes with Cu and Fe. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

3D-Pharmacophore mapping of thymidine-based inhibitors of TMPK as potential antituberculosis agents

Tuberculosis (TB) is the primary cause of mortality among infectious diseases. Mycobacterium tuberculosis monophosphate kinase (TMPKmt) is essential to DNA replication. Thus, this enzyme represents a promising target for developing new drugs against TB. In the present study, the receptor-independent, RI, 4D-QSAR method has been used to develop QSAR models and corresponding 3D-pharmacophores for a set of 81 thymidine analogues, and two corresponding subsets, reported as inhibitors of TMPKmt. The resulting optimized models are not only statistically significant with r (2) ranging from 0.83 to 0.92 and q (2) from 0.78 to 0.88, but also are robustly predictive based on test set predictions. The most and the least potent inhibitors in their respective postulated active conformations, derived from each of the models, were docked in the active site of the TMPKmt crystal structure. There is a solid consistency between the 3D-pharmacophore sites defined by the QSAR models and interactions with binding site residues. Moreover, the QSAR models provide insights regarding a probable mechanism of action of the analogues.