Despite great advances in the chemotherapy of infectious diseases, these are still far from being controlled, or even less eradicated, and are still one of the main causes of death around the world. Particularly troubling is the case of microorganisms that are resistant to commonly used antimicrobials. Another cause of concern is the increasing occurrence of plant diseases caused by microorganisms, particularly fungi, which can reduce performance, quality or even completely destroy crops. Even though there are known and widely used fungicides, resistance to them has already been reported (Vurro et. al., 2010).
Tracing of active molecules from natural sources is the traditional path in the antimicrobial area, and has proven extraordinarily successful, leading to the development of modern anti infectious chemotherapy. This is probably a consequence of the evolution to generate antimicrobials, giving the producing organisms a selective advantage in their environment (Bologna et al., 2013). Given that the known metabolites to date represent a small fraction of the great metabolic diversity, working with less studied organisms opens big possibilities of finding new molecules (Lewis, 2013). The National Institute for investigation in agriculture and cattle farming (INIA) has a microorganism collection, isolated from different sources, such as insects, plants and soil. These are identified and used to promote crop development and as biologic controls for plagues. The extra cellular broths obtained after growing these microorganisms could be an interesting source for new metabolites of interest.
In this current work, we pose to use these culture media to study active molecules against microorganisms. To achieve this, a liquid-liquid extraction of the culture broths of thirteen different microorganisms was made. Antimicrobial activity was tested and we observed growth inhibition of one or more microorganisms of interest by several extracts. Given this, we continued working in the chemical dereplication of some of these extracts. Using bio guided techniques (Rahalison et. al., 1991), we were able to make a primary approach to the identification of the active molecules within the extract, which were later characterized by chromatographic and spectroscopical techniques. Following on from this, we are currently working on the isolation and structural elucidation of the active molecules determined.
Acknowledgments: PEDECIBA Química, Proyecto ANII FCE 3_2016_126616.

References
Bologna, C., Ursu, O., Tudor, O., Melacon, C., Tegos, G.P. (2013) Current Opinion in Pharmacology. 13, 678–687.
Lewis K. (2013) Nature Reviews Drug Discovery. 12(5):371-387.
Rahalison, L, Hamburger, M, Hostettman, K, Monod, M and Frenck E. (1991). Phytochemical Analisis 2, 199-203.
Vurro, M., Bonciani, B., Vannacci, G. (2010). Food Security 2, 113–32.