The triterpenoids oleanolic (OA) and ursolic (UA) acids show non-selective antiinflamatory activity in vitro for cyclooxygenase (COX) isoforms. 3D conformations of OA and UA, with three possible orientations (1, 1' and 2) in the active site of isoforms COX, obtained by docking, were submitted to molecular dynamics. The results show that orientation 2 of the OA in COX-2 is more favorable because orientation 1 moved away from the active site. The carboxylate group of OA interact by hydrogen bonds with Ser353 and with Phe357 and Leu359, mediated by water, while hydroxyl in C-3 interact by hydrogen bond, mediated by water, with Tyr385.

Protein kinases are one of the largest protein families and they are responsible for regulation of a great number of signal transduction pathways in cells, through the phosphorylation of serine, threonine, or tyrosine residues. Deregulation of these enzymes is associated with several diseases including cancer, diabetes and inflammation. For this reason, specific inhibition of tyrosine or serine/threonine kinases may represent an interesting therapeutic approach. The most important types of protein kinases, their structural features and chemical inhibitors are discussed in this paper. Emphasis is given to the small-molecule drugs that target the ATP-binding sites of these enzymes.

This work presents a brief retrospective of José de Freitas Machado's prominent role in the creation, development and consolidation of Chemistry undergraduate courses in Brazil. Freitas Machado defended in many occasions the importance of chemical studies for the economic development of this country. We analyze, here, his important paper "Façamos Químicos" [Let's Make Chemists] (1917), seminal for the implantation of Industrial Chemistry undergraduate courses in Brazil.

Computer simulations of biomolecular systems have achieved a significant importance in science as they provide information regarding structure, dynamics, and energetics of biomolecules that are inaccessible to experimental measuring techniques. In this work, some important aspects of the simulation of biomolecular systems are described. An overview of the most popular protein force fields, simple explicit water models for the simulation of liquid water, and different approaches to treat the boundaries of the system is presented. Also, studies conducted in our group illustrating successful simulations of three biomolecules (thrombin, L-type calcium channel and human Cytomegalovirus protease) through the application of simple explicit water models combined with protein force fields are discussed.

Modeling methods to derive 3D-structure of proteins have been recently developed. Protein homology-modeling, also known as comparative protein modeling, is nowadays the most accurate protein modeling method. This technique can produce useful models for about an order of magnitude more protein sequences than there have been structures determined by experiment in the same amount of time. All current protein homology-modeling methods consist of four sequential steps: fold assignment and template selection, template-target alignment, model building, and model evaluation. In this paper we discuss in some detail the protein-homology paradigm, its predictive power and its limitations.

Wilhelm Michler lived in Brazil for seven years from 1882 to 1889, when he died. Here, he published several articles on natural products, and became a professor of Industrial Chemistry at the Escola Politécnica, in Rio de Janeiro. He was respected by colleagues and students. This article addresses this poorly known period of the life of a scientist, world-famous by the aromatic ketone that carries his name.

In this paper we briefly describe the scientific career of Theodor Peckolt, naturalist and pharmacist, and his seminal contribution to the development of phytochemistry in Brazil. His achievements are discussed in the light of the historical background of the Brazilian science and University at his time.

The molecular basis of modern therapeutics consist in the modulation of cell function by the interaction of microbioactive molecules as drug cells macromolecules structures. Molecular modeling is a computational technique developed to access the chemical structure. This methodology, by means of the molecular similarity and complementary paradigm, is the basis for the computer-assisted drug design universally employed in pharmaceutical research laboratories to obtain more efficient, more selective, and safer drugs. In this work, we discuss some methods for molecular modeling and some approaches to evaluate new bioactive structures in development by our research group.