Antimicrobial metabolites produced by endophytic fungi associated with the leaves of Vochysia divergens.

Investigation of the endophytic fungi Nigrospora sphaerica, Nigrospora oryzae, and Pseudofusicoccum stromaticum MeOH fractions isolated from the leaves of Vochysia divergens, a medicinal species from the Brazilian Pantanal, led to the identification of five compounds, namely a new compound (1E,8Z)-10,11-dihydroxy-5,5,8-trimethyl-4-oxocycloundeca-1,8-diene-1-carbaldehyde (1) and four known compounds: 5-methylmellein (2), sclerone (3), daldinone A (4), and lasiodiplodin (5). All compounds were identified using spectroscopic methods, and 1 was corroborated with mass spectrometry, while the known compounds were compared with data in the literature. The relative configuration of compound 1 was determined based on theoretical conformational studies as well as the J experimental values between the hydroxymethyne hydrogens. The antimicrobial activity of the compounds was evaluated. Promising results were obtained for compounds 2, 4, and 5 since they inhibited the bacterium Pseudomonas aeruginosa, an opportunistic pathogen, suggesting the potential of these microorganisms as a source of new antibacterial agents.

Metabolomic Analysis of Combretum lanceolatum Plants Interaction with Diaporthe phaseolorum and Trichoderma spirale Endophytic Fungi through 1 H-NMR.

Endophytic fungi are an important class of microorganisms, able to interact with a host plant via a mutualistic mechanism without visible symptoms of the fungal colonization. The synergy between endophytic fungi and their host plant can promote morphological, physiological and biochemical changes through the expression of bioactive metabolites. This work aims to correlate metabolic changes in the Combretum lanceolatum plant metabolome with its endophytic fungi Diaporthe phaseolorum (Dp) and Trichoderma spirale (Ts), and to discover corresponding metabolite-biomarkers, with the principal focus being on its primary metabolism. The 1 H-NMR metabolomic analysis of qualitative and quantitative changes was performed through multivariate statistical analysis and the identification of primary metabolites was achieved on the Madison Metabolomics Consortium Database. The presence of Dp significantly impacted the plant's metabolic pathways, improving the biosynthesis of primary metabolites such as threonine, malic acid and N-acetyl-mannosamine, which are precursors of special metabolites involved in plant self-defence. This work represents a valuable contribution to advanced studies on the metabolic profiles of the interaction of plants with endophytes.

Evaluation of antileishmanial activity of harzialactone a isolated from the marine-derived fungus Paecilomyces sp.

Fractionation of extracts from the culture broth of the marine-derived fungus, Paecilomyces sp. 7A22, resulted in the isolation of the harzialactone A (HA), a known compound previously isolated from fungi of marine environments. The chemical structure of HA was determined by spectroscopic analyses. Upon evaluation of HA on antileishmanial assays against Leishmania amazonensis, HA exhibited significant activity against promastigotes forms with IC50 of 5.25 µg mL-1 and moderate activity against intracellular amastigotes with IC50 of 18.18 µg mL-1. This is the first report on the antileishmanial activity of HA, and the effects of HA presented in this work suggest that this class of compounds are suitable for future biological in vitro and in vivo studies for the search of natural products with activity against Leishmania spp. Furthermore, the present results corroborate marine-derived fungi as a promising source of natural products with antiparasitic activity.

Endophytic fungal extracts: evaluation as photosynthesis and weed growth inhibitors.

A central pillar of modern weed control is the discovery of new herbicides which are nontoxic to humans and the environment and which have low application dosage. The natural products found in plants and microorganisms are well suited in this context because they are generally nontoxic and have a wide variety of biological activities. In this work, Diaporthe phaseolorum (Dp), Penicillium simplicissimum (Ps) and Trichoderma spirale (Ts) (methanolic extracts) were evaluated as photosynthesis and plant growth inhibitors in Senna occidentalis and Ipomoea grandifolia. The most significant results were observed for Ts and Dp in S. occidentalis and I. grandifolia, respectively. Ts reduced PI(abs), ET0/CS0, PHI(E0) and PSI0 parameters by 64, 28, 40 and 38%, respectively, indicating a reduction on electron transport efficiency. Additionally, Ts decreased shoot length by 9%, affecting the plant growth. Dp reduced PI(abs), ET0/CS0 and PHI(E0) parameters by 50, 20, 26 and 22%, respectively, revealing the inhibition competency on PSII acceptor site. Furthermore, Dp decreased by 50% the shoot length on germination assay. Thus, the phytotoxic behaviors based on endophytic fungal extracts may serve as a valuable tool in the further development of a bioherbicide since natural products represent an interesting alternative to replace commercial herbicides.