Antimicrobial activity of defensive secretions of terrestrial invertebrates (Diplopoda, Spirobolida, Rhinocricus) from the insular neotropics.

In the last 30 years, a significant increase in resistance of pathogenic microorganisms (to humans and animals) to conventional therapeutic strategies has been observed, in an alarming manner, which constitutes, per se, a drive force and need for the search of new products or bioactive molecular systems of low toxicity, high specificity of action and bioavailability, for the treatment of diseases (dermatological, respiratory, gastrointestinal, etc.) generated by microbial pathogens. In this molecule- antimicrobial bioactivity race, should be emphasized the ethnobotanical and traditional use of plants and microorganisms and their secondary metabolites (botanical extracts, peptides, monoterpenes and triterpenoids, alkaloids) modified or not biotechnologically. In this context, it should be noted that the search for agents with antimicrobial activity from natural sources such as terrestrial invertebrates associated with mega edapho-fauna has not been considered as a source of poly-component systems or molecular entities with potential antimicrobial action. The defensive secretions of Diplopods (millipedes, Spirobolida), given the presence of benzenoids and volatile monoterpenes, possess recognized antimicrobial activity. In the present communication we report the isolation of repugnatorial secretions from millipedes gen. Rhinocricus inhabiting in Cuban neotropical island conditions and the analysis, by GC/Ms, of their composition pattern, highlighting the existence of hydroxylated quinonoids (methylhydroxylated benzoquinones, phenolic derivatives, amines, aldehydes) that show, under in vitro conditions, a significative antimicrobial activity against pathogenic microorganisms (Candida albicans, Epidermophyton sp, Mycosporum sp, etc.). These natural derivatives can be used, as bioactive components, in formulations for topical treatment of epidermal infections of microbial origin.