RESUMO
Social insects establish complex interactions with microorganisms, some of which play defensive roles in colony protection. The important role of pollinators such as the stingless bee Melipona scutellaris in nature encouraged us to pursue efforts to study its associated microbiota. Here we describe the discovery of two novel cyclic hexadepsipeptides, meliponamycin A (1) and meliponamycin B (2), from Streptomyces sp. ICBG1318 isolated from M. scutellaris nurse bees. Their structures were established by interpretation of NMR and MS data, and the absolute configuration of the constituent amino acids was determined by the advanced Marfey's method. Compounds 1 and 2 showed strong activity against the entomopathogen Paenibacillus larvae and human pathogens Staphylococcus aureus and Leishmania infantum.