Asymmetric synthesis and evaluation of epoxy-α-acyloxycarboxamides as selective inhibitors of cathepsin L.

Cathepsin L plays important roles in physiological processes as well as in the development of many pathologies. Recently the attentions were turned to its association with tumor progress what makes essential the development of more potent and selective inhibitors. In this work, epoxipeptidomimetics were investigated as new cathepsin inhibitors. This class of compounds is straightforward obtained by using a green one-pot asymmetric epoxidation/Passerini 3-MCR. A small library of 17 compounds was evaluated against cathepsin L, and among them LSPN423 showed to be the most potent. Investigations of the mechanism suggested a tight binding uncompetitive inhibition.

Immobilized cholinesterases capillary reactors on-flow screening of selective inhibitors.

The discovery of selective inhibitors for acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) is extremely important for the development of drugs that can be used in the treatment of patients diagnosed with the Alzheimer's disease (AD). For this reason, there is a growing interest in developing rapid and effective assays techniques for cholinesterases (ChE) enzymes ligand screening. Herein is presented the results of selective screening assays of a coumarin derivatives library using BChE and AChE covalently immobilized onto silica fused capillaries (ICERs, 15 cm × 0.1 mm ID). The statistical comparison of the ICERs screening assay with that of the free enzymes is reported and highlights the advantages of the on-flow ICERs assay. Two out of 20 coumarin derivatives could be highlighted: compound 17 is more active toward BChE (IC50=109 ± 21 µM) and 19 showed activity against both enzymes (BChE IC50=128 ± 28 µM and hu-AChE IC50=144 ± 40 µM). The statistical evaluation of the results of the ICERs and free enzyme assays showed no difference between them, further validating the ICERs assay model. The ICERs ability to recognize selective ligands and its use for characterization of the inhibition mechanisms of the hits consolidates the approach here reported.

Enantioselective disposition of omeprazole, pantoprazole, and lansoprazole in a same Brazilian subjects group.

This work reports the result of the enantioselective disposition of pantoprazole, omeprazole, and lansoprazole in a same group of Brazilian health subjects. Ten nongenotyped healthy subjects were used for this study. Each subject received a single oral dose of 80 mg of pantoprazole, 40 mg of omeprazole, and 30 mg of lansoprazole, and the plasma concentrations of the enantiomers were measured for 8 h postdose. For pantoprazole and omeprazole, among the 10 volunteers investigated, only one volunteer (Subject # 4) presented higher plasma concentrations of the (+)-enantiomer than those of (-)-enantiomer. Nevertheless, the area under the concentration-time curve of the (+)-lansoprazole was higher than those the (-)-lansoprazole for all subjects. The comparison of proton pump inhibitors' enantiomers disposition from a single group volunteer demonstrated that pantoprazole and omeprazole can be used to differentiate extensive from poor CYP2C19 metabolizer while lansoprazole cannot do it.