Indolealkylamines in the venom of the scorpion Thorellius intrepidus.

Scorpions are a group of arthropods that strike fear in many people due to their severe medical symptoms, even death, caused by their venomous stings. Even so, not all scorpion species contain harmful venoms against humans but still have valuable bioactive molecules, which could be used in developing new pharmaceutical leads for treating important diseases. This work conducted a comprehensive analysis of the venom from the scorpion Thorellius intrepidus. The venom of T. intrepidus was separated by size exclusion chromatography, and four main fractions were obtained. Fraction IV (FIV) contained small molecules representing over 90% of the total absorbance at 280 nm. Analysis of fraction FIV by RP-HPLC indicated the presence of three main molecules (FIV.1, FIV.2, and FIV.3) with similar UV absorbance spectra profiles. The molecular masses of FIV.1, FIV.2, and FIV.3 were determined, resulting in 175.99, 190.07, and 218.16 Da, respectively. Further confirmation through 1H-NMR and 13C-NMR analyses revealed that these molecules were serotonin, N-methylserotonin, and bufotenidine. These intriguing compounds are speculated to play a pivotal role in self-defense and increasing venom toxicity and could also offer promising biotechnological applications as small bioactive molecules.

Antimicrobial Compounds from Skin Secretions of Species That Belong to the Bufonidae Family.

Skin secretions of toads are a complex mixture of molecules. The substances secreted comprise more than 80 different compounds that show diverse pharmacological activities. The compounds secreted through skin pores and parotid glands are of particular interest because they help toads to endure in habitats full of pathogenic microbes, i.e., bacteria, fungi, viruses, and protozoa, due to their content of components such as bufadienolides, alkaloids, and antimicrobial peptides. We carried out an extensive literature review of relevant articles published until November 2022 in ACS Publications, Google Scholar, PubMed, and ScienceDirect. It was centered on research addressing the biological characterization of the compounds identified in the species of genera Atelopus, Bufo, Duttaphrynus, Melanophryniscus, Peltopryne, Phrynoidis, Rhaebo, and Rhinella, with antibacterial, antifungal, antiviral, and antiparasitic activities; as well as studies performed with analogous compounds and skin secretions of toads that also showed these activities. This review shows that the compounds in the secretions of toads could be candidates for new drugs to treat infectious diseases or be used to develop new molecules with better properties from existing ones. Some compounds in this review showed activity against microorganisms of medical interest such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Coronavirus varieties, HIV, Trypanosoma cruzi, Leishmania chagasi, Plasmodium falciparum, and against different kinds of fungi that affect plants of economic interest.