The serine peptidases, thrombocytin and PA-BJ, isolated from the venom of Bothrops atrox and Bothrops jararaca, respectively, induce platelet aggregation and granule secretion without clotting fibrinogen. The specific platelet aggregation activity of each enzyme was about 15 times lower than that of thrombin. This activity was blocked by monoclonal antibodies recognizing protease activated receptor 1 (PAR1) and by heparin, but not by hirudin nor thrombomodulin. Both enzymes induced calcium mobilization in platelets and desensitized platelets to the action of thrombin and the SFLLRN peptide. We compared the effect of thrombin, PA-BJ, and thrombocytin on the degradation of the soluble N-terminal domain of the PAR1 receptor. The major cleavage site by thrombin and both viper enzymes was Arg41^Ser42. In addition, a rapid cleavage of the peptide bond at Arg46^Asn47 by the viper enzymes was observed, resulting in the inactivation of the tethered ligand. PA-BJ and thrombocytin both cleaved at 41^42 and 46^47 peptide bonds, and fragment 42^103 disappeared rapidly. Both viper enzymes caused calcium mobilization in fibroblasts transfected with PAR4 and desensitized these cells to the thrombin action. In conclusion, both PAR1 and PAR4 mediate the effect of viper venom serine peptidases on platelets. ß

Functionalization of 2,1,3‐benzothiadiazole (BTD) with thiols at C‐5 position remains low explored. Moreover, the arylthiol‐substitutions at this position are also unexplored and can not be found by a SN2 or SN1 reaction. In this sense, herein we present a new palladium‐catalyzed methodology for a wide variety of unpublished 5‐arylsulfanyl‐benzo‐2,1,3‐thiadiazole derivatives synthesis with moderate to high yields using a low catalytic loading of Pd(L‐Pro)2 as low‐coast, and efficient catalyst in low reaction time. Besides, we concluded that the pKa of thiol species has an important role in this catalysis, mainly in the CMD like catalytic cyclo process, which strongly interferes in the reaction yields. Furthermore, arylsulfanyl‐benzo‐2,1,3‐thiadiazoles derivatives have been assessed (in vitro) as potential acetylcholinesterase inhibitors.

A simple, efficient and green methodology for the C−S cross‐coupling reaction using Pd(L‐Pro)2 as a heterogeneous catalyst was developed involving aryl iodides, thiols, green‐solvent and a low catalytic loading of palladium prolinate. In addition, the catalyst turned out to be recyclable and the products were obtained in good to excellent yields.

Background: Sulfur-containing compounds represent an important class of chemical compounds due to their wide range of biological and pharmaceutical properties. Moreover, sulfur-containing compounds may be applied in other fields, such as biological, organic, and materials chemistry. Several studies on the activities of sulfur compounds have already proven their anti-inflammatory properties and use to treat diseases, such as Alzheimer’s, Parkinson’s, and HIV. Moreover, examples of sulfur-containing compounds include dapsone, quetiapine, penicillin, probucol, and nelfinavir, which are important drugs with known activities. Objective: This review will focus on the synthesis and application of some sulfur-containing compounds used to treat several diseases, as well as promising new drug candidates. Results: Due to the variety of compounds containing C-S bonds, we have reviewed the different synthetic routes used toward the synthesis of sulfur-containing drugs and other compounds.