Maria Michela Salvatore

Aphanomyces euteiches is a destructive soilborne oomycete affecting legumes worldwide. Although its pathogenic mechanisms have been extensively investigated, its specialized metabolism remains largely unexplored. In this study, organic extracts of A. euteiches grown on two different media were tested across five legume species. The PDA-EtOAc extract induced the most severe yellowing and necrotic lesions on leaves, especially in pea and lentil, and markedly reduced root growth, with associated necrosis, in all legumes evaluated. GC-MS and 1H NMR profiling identified major fatty acids together with phenolic compounds and diketopiperazines potentially involved in microbial signaling. Daidzein and genistein, two plant isoflavones, were also identified in A. euteiches organic extracts for the first time. This finding challenges the current view that these metabolites detected during infection originate exclusively from legume hosts and suggests that they may also participate in pathogen biology and host–pathogen interactions.

The specialized metabolite profile of Rubus ulmifolius Schott leaves collected in Algeria was investigated, and their biological activities were evaluated using complementary in vitro and in silico approaches. Leaf extracts were obtained by maceration followed by n ‐hexane and dichloromethane fractionation, as well as by Soxhlet extraction using n ‐hexane. Quantitative analyses of polyphenols, flavonoids, and flavonols showed that phytochemical contents varied according to the solvent polarity and extraction method, a pattern further confirmed by GC‐MS analysis of the chemical profiles. In vitro antioxidant assays indicate that HE‐M ( n ‐hexane fraction after maceration) exhibited the strongest activity, particularly in ABTS ⁺ (IC ₅₀ = 12.76 ± 0.26 µg/mL) and phenanthroline ( A _0.5 = 19.33 ± 0.95 µg/mL) assays, reflecting higher radical scavenging and metal‐chelating capacities. Antimicrobial assays revealed that all extracts exhibited moderate to notable antibacterial and antifungal effects against certain strains, whereas DM‐M (dichloromethane fraction) displayed particularly strong activity against most tested strains. Molecular docking against bacterial DNA gyrase‐A (GyrA) showed that glycerol monostearate, phytol, and methyl caffeate demonstrated favorable binding energies and interactions, providing a plausible molecular explanation for the observed antibacterial activity. Overall, these findings suggest that specialized metabolites produced by R. ulmifolius possess significant antioxidant and antibacterial potential, highlighting their promise as natural bioactive agents.

Extremophilic fungi are a relatively unexplored source of stress-resilient microbes for sustainable agriculture. Here, we describe Talaromyces pseudofuniculosus FAR, isolated from the highly acidic site of “Piccolo Inferno” in southern Italy and identified by ITS and β-tubulin (BenA) sequencing. Despite its origin from an extreme environment, T. pseudofuniculosus FRA remained fully functional under non-stress conditions and displayed tolerance to salinity and heavy metals while maintaining key plant growth-promoting traits, including phosphate solubilization, auxin-related compound production and hydrolytic activities. In soybean (Glycine max L.), the live fungus promoted plant growth under both non-stress conditions and agriculturally relevant salinity and copper stress, and successfully colonized the roots. A cell-free extracellular extract (exCFS) promoted early seedling development in vitro, but its effects were not sustained in pot experiments. GC–MS analysis provided a qualitative characterization of the extracellular metabolite profile and revealed condition-dependent differences between control, NaCl and CuSO₄ growth conditions, indicating environment-dependent modulation of fungal metabolism. Overall, these findings highlight the physiological and metabolic plasticity of T. pseudofuniculosus FRA and support its potential as a fungal biostimulant for saline- and metal-impacted agricultural soils.

Four sesquiterpenes, namely tomentosin, 11α,13-dihydrotomentosin, inuviscolide, and α-costic acid, were isolated from the aerial parts of the medicinal plant Dittrichia viscosa (L.) Greuter and evaluated for antiproliferative activity against HCT116 colorectal and A549 lung cancer cells. All compounds reduced cell viability in a concentration-dependent manner, with tomentosin and inuviscolide exhibiting the greatest activity among the tested compounds and IC₅₀ values in the moderate micromolar range. Evaluation in non-malignant human neonatal dermal fibroblasts (HDFn) revealed compound- and cancer-type-dependent selectivity, with inuviscolide showing greater selectivity toward HCT116 cells and tomentosin showing moderate selectivity toward both cancer cell lines. In silico ADMET and DFT analyses characterized the predicted drug-likeness, pharmacokinetic, toxicity-related, and electronic properties of the compounds, particularly tomentosin and inuviscolide. Network pharmacology prioritized STAT3, ESR1, and PTGS2 as candidate hub targets associated with both cancer types, while enrichment analyses identified pathways related to tumor proliferation, inflammation, immune regulation, and cellular stress. Noncovalent molecular docking, 200 ns molecular dynamics simulations, and MM/GBSA calculations supported possible modeled interactions of tomentosin and inuviscolide with these proteins, with tomentosin displaying the most favorable predicted binding profile. Covalent docking further identified structurally feasible STAT3 CYS687-linked poses with the two sesquiterpenes, although covalent adduct formation and direct target engagement remain to be experimentally validated. Overall, the integrated findings prioritize tomentosin and inuviscolide as D. viscosa-derived natural-product scaffolds with moderate antiproliferative activity for further structural optimization, selectivity assessment, and experimental mechanistic validation.

This study aimed to valorize Erica arborea L. collected in Algeria by characterizing its chemical composition and assessing the biological potential of its organic extracts. The aerial nonflowering parts were extracted using solvents of increasing polarity, allowing evaluation of chemical and biological properties of extracts. Phytochemical assays revealed that the ethyl acetate (EtOAc) fraction contained the highest levels of total polyphenols (419.58 ± 1.89 µg GAE/mg), flavonoids (174.57 ± 1.93 µg QE/mg), and flavonols (61.64 ± 2.49 µg QE/mg). GC–MS profiling confirmed the presence of several bioactive constituents, supporting its rich chemical composition. Antioxidant activity highlighted the superiority of EtOAc extract, with IC ₅₀ of 5.07 ± 0.63 μg/mL in the ABTS ^•+ assay, 26.96 ± 1.16 μg/mL in the DPPH ^• assay, and an A _0.5 of 18.14 ± 0.57 μg/mL in the FRAP test, while the phenanthroline assay showed strong reducing power across all extracts ( A _0.5 = 1.25 ± 0.05–6.72 ± 0.15 μg/mL). Antimicrobial activity revealed that the EtOAc fraction exhibited notable activity against Staphylococcus aureus (19.33 ± 0.57 mm) and Bacillus subtilis (19.0 ± 1.0 mm), while all fractions showed antifungal activity against Candida albicans and Fusarium oxysporum . Molecular docking on xanthine oxidase and DNA gyrase (GyrA and GyrB) revealed favorable interactions of several metabolites, supporting the antioxidant and antibacterial activities observed experimentally.

Fusarium oxysporum f. sp. lycopersici (Fol) is a destructive soil-borne pathogen responsible for major global losses in tomato production, within a context of increasingly constrained fungicide use in intensive farming systems. Sustainable alternatives to chemical fungicides are urgently needed, and microbial secondary metabolites represent a promising source of antifungal compounds. This study explores the antifungal potential of secondary metabolites produced by a natural isolate of Beauveria bassiana (Bb758) previously reported to exhibit strong biocontrol activity against Fol. LC-HRMS metabolomic profiling revealed a chemically diverse metabolite profile dominated by amino acid-derived compounds, peptides and alkaloids. Purification of the crude extract by column chromatography and reverse-phase HPLC yielded beauvericin and several 2,5-diketopiperazines as the main bioactive constituents. These compounds were identified by NMR and LC-HRMS analyses. The antifungal activity of beauvericin (BEA), cyclo(l-Phe-l-Pro) (CFP) and fractions was evaluated against spore germination and germ tube development of Fol. BEA exhibited dose-dependent but limited activity, showing significant inhibition only at high concentrations (100 μg mL⁻¹). In contrast, CFP showed significantly higher antifungal activity than BEA, inhibiting both germination and germ tube formation at concentrations as low as 10 μg mL⁻¹. These results identify CFP as a promising antifungal compound targeting the early infection stages of Fol and highlight fungal-derived diketopiperazines as candidate molecules for sustainable disease management strategies.

1. Species of Lasiodiplodia are cosmopolitan plant pathogens responsible of dieback and canker in a broad range of plants, including Theobroma cacao L., Vitis vinifera L., and Mangifera indica L. (...

During infection in vitro with the strain 438/06 of bovine coronavirus (BCoV), a β-coronavirus similar to severe acute respiratory syndrome (SARS) CoV-2, treatment with 6-pentyl-α-pyrone (6PP), a fungal metabolite obtained from Trichoderma atroviride, was recently shown to influence viral load by reducing viral entry. Herein, the ability of 6PP to counteract the BCoV infection was further investigated both in vitro and in silico. Following the BCoV (strain 282/23) infection in bovine (MDBK) cells, the 6PP in co-treatment increased cell viability, reduced morphological signs of cell death, and significantly inhibited viral yield, by lessening the expression of the viral spike (S) protein, as well as the gene transcription of the viral nucleocapsid (NP) protein. In addition, a noticeable down-regulation in the expression of aryl hydrocarbon receptor (AhR) signaling, a strategic modulator of CoVs infection, was found. Molecular docking studies were performed to evaluate the potential interaction between 6PP and AhR involved in the BCoV infection. The docking 3D structural model showed that 6PP fits into a binding pocket positioned between the PASB and TAD domains of bovine AhR (bAhR), where the ligand is stabilized through hydrophobic interactions. In addition, the obtained computational data strongly suggest that the bAhR binding mechanism of 6PP is principally mediated by a well-conserved hydrophobic cavity playing a key role in the modulation of the receptor functions. Overall, our findings showed an antiviral action of 6PP versus BCoV infection in vitro and in silico.