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.

The continuous search for biologically active compound candidates pushes the pursuit of new substances produced by diverse organisms. Endophytic fungi are known as a promising source of metabolites with several biological activities. Based on the rich Amazonian biodiversity and the chemical potential of microbial sources, three Talaromyces strains, all major endophytes from their respective host plants, were studied aiming at the isolation of biologically active secondary metabolites. Through classical chromatographic approaches, 13 compounds were isolated from the antimicrobial extracts of the studied strains. From these, polyketides, steroids, anhydrides, and phenolic compounds were identified. Among them, two previously undescribed compounds were elucidated based on spectroscopic and spectrometric methods, a homodimer chromanone and a maleic anhydride methyl ester. The antimicrobial activity against a panel of pathogenic microorganisms from extracts, fractions, and isolated compounds was evaluated.

DgCr22.1b, um isolado endofítico de Talaromyces sp., foi coletado na Floresta Amazônica a partir da planta medicinal Duguetia stelechantha. Do fracionamento do extrato metanólico de sua massa micelial, foi isolada uma nova xantona dimérica talaroxantona. A estrutura deste novo composto foi elucidada com base em análises espectroscópicas incluindo experimentos de ressonância magnética nuclear (RMN) 2D.

DgCr22.1b, an endophytic isolate of Talaromyces sp., was collected in the Amazonian Rainforest from the medicinal plant Duguetia stelechantha. From the fractionation of the methanolic mycelial extract, a new xanthone dimer talaroxanthone was isolated. The structure of this new compound was elucidated based on spectroscopic analyses including 2D nuclear magnetic resonance (NMR) experiments.

Mauritia flexuosa L. f., Arecaceae, is an endemic species of South America. This species was studied with the intent to isolate the constituents of its roots. After the fractionation of the n-hexane and methanolic extracts from the roots of M. flexuosa, six triterpenes were obtained: friedelin, taraxerone, lupenyl acetate, lupenone, betulin and betulinic acid, along with three flavonoids: rutin, quercitrin and quercetin. All the compounds were identified by analysis of NMR and MS data and comparison with the literature. All those compounds are been reported for the first time in Mauritia, and the chemosystematic significance of the flavonoids isolated in this genus is discussed.