Metabolomic Profiling of Endophytic Fungi and the Host Plant Annona jahnii Saff. Reveals Shared and Analogous Compounds

Endophytic fungi are a viable option for obtaining metabolites identical or analogous to those produced by the host plant. However, research on the ability of these microorganisms to biosynthesize these metabolites is still scarce, although important to enable their use for this purpose, contributing to the preservation of the host plant. The metabolomic study of fungal (<i>Penicillium sumatraense</i>, <i>Penicillium miczynskii</i>, <i>Penicillium osmophilum</i>, and <i>Penicillium chermesinum</i>) and plant extracts was carried out using UHPLC/ESI-MS/MS analyses combined with exploratory analysis by Molecular Networking (MN). Antioxidant activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical method was performed on fungal and plant extracts. The exploratory analysis by MN showed 75 MS features that were detected in the fungi and the host plant; of these, four compounds were putatively identified. The analysis showed 539 MS features with structural similarity to both biological matrices. Fungal extracts showed more promising antioxidant activities when compared to the plant extract. UHPLC combined with Molecular Networking proved to be a powerful strategy to guide the identification of microorganisms capable of biosynthesizing metabolites produced by the host plant. The strategy allowed for an early and efficient evaluation of crude extracts and provided unprecedented information regarding the chemical profile of <i>A. jahnii</i> and its endophytic fungi.