Penicillium meliponae, a recently described and rare species, was isolated as an endophytic fungus from the Amazonian plant Duguetia sthelechantha, and has been proven to be a pigment producer. Considering the high productivity of this species and the lack of data on its chemical composition, the present study aimed to characterize the chemical profile of P. meliponae and evaluate the influence of agitation and the use of different culture media. For this purpose, liquid chromatography coupled with mass spectrometry (LC-MS/MS) and molecular networking were used, allowing the identification of 17 azaphilone molecules with sclerotiorin-like skeletons, becoming the first chemical report of this species. In addition, the different production patterns in the tested culture media were indicative that this species is sensitive to changes in the composition of the carbon source and to the presence of agitation. Furthermore, this work contributes to the fragmentation mechanisms of the different possible structural arrangements for azaphilones of the sclerotiorin type and serves as a repository of information on the gas-phase behavior of this type of metabolite in mass spectrometry experiments and will assist future studies aimed at the discovery of azaphilones.

The genus Penicillium is among the most promising alkaloid-producing fungal and therefore plays an important role in terms of producing molecules with biotechnological potential. Thus, in order to identify alkaloid-producing fungi, 25 endophytic Penicillium strains previously isolated from Amazon medicinal plants were subject to an integrative approach based on direct infusion positive electrospray ionization mass spectrometry (ESI-MS) and principal component analysis (PCA). The multivariate analysis pointed paxiline (1), glandicoline B (2), roquefortine C (3), and oxaline (5) as responsible for the segregation of three promising alkaloid-producing groups, been these groups constituted for P. chrysogenum, P. oxalicum, P. paxilli, and P. rubens strains. These alkaloids and the glandicoline A (4) were tentatively identified by multiple-stage mass spectrometry. In addition, compounds 1 and 2 were isolated and confirmed by using 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. Overall, the chemical profile analysis by ESI-MS along with PCA provided a simple and effective approach to screening alkaloid-producing Penicillium strains for biotechnological applications.