ISOLATION AND IDENTIFICATION OF ANTIMICROBIAL COMPOUNDS BIOSYNTHESIZED BY ACTINOBACTERIA OBTAINED FROM BRAZILIAN SOIL

• Grant number: 24/22121-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Health Sciences - Pharmacy - Pharmacognosy
• Principal Investigator: Mônica Tallarico Pupo
• Grantee: Gabriel Picolo de Castro
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Natural products play a crucial role in drug development due to their chemical diversity and biochemical specificity. Approximately 50% of FDA-approved drugs between 1981 and 2019 are derived from or related to natural products. However, emerging microbial resistance represents a significant challenge, necessitating the search for new compounds with antimicrobial potential. Environmental microorganisms, especially those from soil, are a promising source of bioactive secondary metabolites, although their biosynthetic potential remains largely unexplored. This project aims to chemically investigate the actinobacteria strain A5.1Q1, isolated from Brazilian soil using the innovative iCHIP technique. The main objective is to isolate and elucidate the chemical structures of active compounds produced by this strain, with a special focus on their activity against human pathogens Candida albicans and Staphylococcus aureus, as well as their ability to inhibit pyocyanin biosynthesis in Pseudomonas aeruginosa. The methodology involves optimizing cultivation conditions using the OSMAC technique, followed by extraction and fractionation of metabolites. Active fractions will be analyzed by HPLC-DAD-ELSD and high-resolution mass spectrometry. Large-scale cultivation will allow for the isolation of compounds of interest through chromatographic techniques, including semi-preparative HPLC. Preliminary results have already identified the production of prodigiosin analogs (streptorubin and undecylprodigiosin) and a possible new prolinolexin analog. Complete structural elucidation will be performed by NMR and mass spectrometry. The isolated compounds will be tested for their antimicrobial activity and ability to inhibit pyocyanin production.