1,2,3-triazoles are potential candidates for molecular modeling of new antithrombotic drugs.

Phospholipases A (PLAs) are important enzymes present in snake venoms and are related to a wide spectrum of pharmacological effects, however the toxic potential and therapeutic effects of acidic isoforms have not been fully explored and understood. Due to this, the present study describes the isolation and biochemical characterization of two new acidic Asp49-PLAs from Bothrops brazili snake venom, named Braziliase-I and Braziliase-II. The venom was fractionated in three chromatographic steps: ion exchange, hydrophobic interaction and reversed phase. The isoelectric point (pI) of the isolated PLAs was determined by two-dimensional electrophoresis, and 5.2 and 5.3 pIs for Braziliase-I and II were observed, respectively. The molecular mass was determined with values ​​of 13,894 and 13,869Da for Braziliase-I and II, respectively. Amino acid sequence by Edman degradation and mass spectrometry completed 87% and 74% of the sequences, respectively for Braziliase-I and II. Molecular modeling of isolated PLAs using acid PLABthA-I-PLA from B. jararacussu template showed high quality. Both acidic PLAs showed no significant myotoxic activity, however they induced significant oedematogenic activity. Braziliase-I and II (100μg/mL) showed 31.5% and 33.2% of cytotoxicity on Trypanosoma cruzi and 26.2% and 19.2% on Leishmania infantum, respectively. Braziliase-I and II (10μg) inhibited 96.98% and 87.98% of platelet aggregation induced by ADP and 66.94% and 49% induced by collagen, respectively. The acidic PLAs biochemical and structural characterization can lead to a better understanding of its pharmacological effects and functional roles in snakebites pathophysiology, as well as its possible biotechnological applications as research probes and drug leads.

Cardiovascular diseases represent the major cause of death and morbidity in the world. An uncontrolled activation of the coagulation cascade and platelet aggregation may lead to the formation of thrombi. Antithrombotic drugs have limitations and may produce side effects, and consequently, alternative therapies have been extensively investigated. Thus, the aim of this work was to evaluate anticoagulant and antiplatelet effects of extracts (prepared in methanol, dichloromethane, ethyl acetate or acetone) of the Brazilian alga Acanthophora spicifera and some commercial products, biotin, myristic acid, cholesterol, β-carotene and vitamin B 12 . Samples were tested on Prothrombin Time, Activated Partial Thromboplastin Time, Fibrinogen Coagulation and Thrombin Time, which are routinely used at clinical trials and on platelet aggregation. From the result, all extracts or products inhibited plasma coagulation as well as inhibited platelet aggregation induced by collagen or ADP. Moreover, the extracts inhibited the enzymatic activity of thrombin, tested upon a specific chromogenic for thrombin. The extracts or commercial products were devoid of toxicity, since no lyse occurred on platelets or red blood cells in the presence of them. In conclusion, the extracts of A. spicifera or products from the market have biotechnological potential and may be useful to develop a new class of antihemostatic drugs.