ABSTRACT. Aedes albopictus, a mosquito originally from Southeast Asia, is considered to be one of the main vectors of dengue fever, yellow fever and other arboviruses. We examined the genetic variability and population structure of 68 individuals of Ae. albopictus collected from five neighborhoods of the city of Manaus, based on the mitochondrial gene coding for NADH dehydrogenase subunit 5 (ND5). Two haplotypes were found, separated by a single mutational event (T ↔ C), with extremely low levels of genetic variability (h = 0.187 ± 0.059; π = 0.00044 ± 0.00014). Based on AMOVA, we concluded that most of the variation (99.08%) occurred within populations, though the levels of variation were not significant. Neutrality tests (Tajima's D and Fu's Fs) were non-significant, indicating that these populations are in genetic equilibrium. The most frequent haplotype (H1) is restricted to Brazilian populations of Ae. albopictus, while the rarer haplotype (H2) is shared with populations from the United States and Asia. We suggest that the reduced variability and low genetic structure identified in our study is a consequence of the recent introduction of this species in Manaus, possibly through a founder effect, followed by expansion throughout the city neighborhoods. Genetic similarity would therefore be due to insufficient time to have accumulated genetic differences between the populations of Ae. albopictus and not to extensive gene flow among them.

In this work we aimed to perform an in silico predictive screening, docking and molecular dynamic study to identify 1,2,3-triazole-phthalimide derivatives as drug candidates against SARS-CoV-2. The in silico prediction of pharmacokinetic and toxicological properties of hundred one 1,2,3-triazole-phtalimide derivatives, obtained from SciFinderV R library, were investigated. Compounds that did not show good gastrointestinal absorption, violated the Lipinski's rules, proved to be positive for the AMES test, and showed to be hepatotoxic or immunotoxic in our ADMET analysis, were filtered out of our study. The hit compounds were further subjected to molecular docking on SARS-CoV-2 target proteins. The ADMET analysis revealed that 43 derivatives violated the Lipinski's rules and 51 other compounds showed to be positive for the toxicity test. Seven 1,2,3-triazole-phthalimide derivatives (A7, A8, B05, E35, E38, E39, and E40) were selected for molecular docking and MFCC-ab initio analysis. The results of molecular docking pointed the derivative E40 as a promising compound interacting with multiple target proteins of SARS-CoV-2. The complex E40-M pro was found to have minimum binding energy of À10.26 kcal/mol and a general energy balance, calculated by the quantum mechanical analysis, of À8.63 eV. MD simulation and MMGBSA calculations confirmed that the derivatives E38 and E40 have high binding energies of À63.47 ± 3 and À63.31 ± 7 kcal/mol against SARS-CoV-2 main protease. In addition, the derivative E40 exhibited excellent interaction values and inhibitory potential against SAR-Cov-2 main protease and viral nucleocapsid proteins, suggesting this derivative as a potent antiviral for the treatment and/or prophylaxis of COVID-19.

ABSTRACT

No abstract

Rice (Oryza sativa L.) is one of the most important crops in the world, and it is considered the primary source of nutritional layout in developing countries in Asia. The glutathione S-transferases (GSTs) superfamily confers to rice protection against biotic and abiotic stress, and herbicide resistance. However, the three-dimensional structure of a GST Tau class, is unsolved. The objectives of this work were to develop a reliable comparative model for the s-transferase glutathione class Tau 4 from rice, and simulate docking interactions, against herbicides bentazon and metsulfuron. Results showed that the predicted model is reliable and has structural quality. Ramachandran plot set 91.9% of the residues in the most favored regions. All complexes showed negative binding energies values; and metsulfuron docked to the glutathione tripeptide, and it represents a possible insilico evidence of glutathione conjugation with this herbicide.