Uncovering the mechanisms of heartwood formation and wood resistance to fungal degradation in the tropical Lauraceae tree Sextonia rubra (Mez.) van der Werff.

Heartwood formation is a complex process that contributes to ensuring the integrity of trunks and the longevity of trees. We examined this mechanism in the tropical angiosperm Sextonia rubra in relation to the spatial distribution of specialised metabolites and their functional role at the scale of a mature individual. Heartwood formation was analysed starting from the examination of one of its properties, namely the decay resistance, of the different S.

Reverse chemical ecology to study the defense of the plant host Sextonia rubra and the chemical mediators of its endophyte Fusarium falciforme against phytopathogen Trametes versicolor.

Sextonia rubra is a tropical tree endemic to the Guiana Shield and the Brazilian Amazon. Despite its renowned wood durability, it remains susceptible to degradation by white-rot fungi such as Trametes versicolor. To mitigate biotic stresses, plants can rely on their associated microbial communities, including endophytes, which play a crucial role in their defense mechanisms.

Chemical Investigation of the Calcareous Marine Sponge , Clathridine-A Related Derivatives Isolation, Synthesis and Osteogenic Activity.

As a result of screening a panel of marine organisms to identify lead molecules for the stimulation of endochondral bone formation, the calcareous sponge was identified to exhibit significant activity during endochondral differentiation. On further molecular networking analysis, dereplication and chemical fractionation yielded the known clathridine A-related metabolites and the homodimeric complex (clathridine A) Zn (), together with the new unstable heterodimeric complex (clathridine A-clathridimine)Zn (). With the presence of the zinc complexes annotated through the LC-MS analysis of the crude extract changing due to the instability of some metabolites and complexes constituting the mixture, we combined the isolation of the predicted molecules with their synthesis in order to confirm their structure and to understand their reactivity.

Spatialized Metabolomic Annotation Combining MALDI Imaging and Molecular Networks.

MALDI mass spectrometry imaging has gained major interest in the field of chemical imaging. This technique makes it possible to locate tens to hundreds of ionic signals on the sample surface without any a priori. One of the current challenges is still the limited ability to annotate signals in order to convert / values into probable chemical structures.

Wood Degradation by M. Fischer: Exploring Fungal Adaptation Using Metabolomic Networking.

M. Fischer (Fmed) is a white-rot wood-decaying fungus associated with one of the most important and challenging diseases in vineyards: Esca. To relieve microbial degradation, woody plants, including , use structural and chemical weapons.

Metabolic adjustments in response to ATP spilling by the small DX protein in a strain.

ATP wasting is recognized as an efficient strategy to enhance metabolic activity and productivity of specific metabolites in several microorganisms However, such strategy has been rarely implemented in species whereas antibiotic production by members of this genus is known to be triggered in condition of phosphate limitation that is correlated with a low ATP content. In consequence, to assess the effects of ATP spilling on the primary and specialized metabolisms of , the gene encoding the small synthetic protein DX, that has high affinity for ATP and dephosphorylates ATP into ADP, was cloned in the integrative vector pOSV10 under the control of the strong E promoter. This construct and the empty vector were introduced into the species yielding A37 and A36, respectively.

Classification of Environmental Strains from Order to Genus Levels Using Lipid and Protein MALDI-ToF Fingerprintings and Chemotaxonomic Network Analysis.

During the last two decades, MALDI-ToF mass spectrometry has become an efficient and widely-used tool for identifying clinical isolates. However, its use for classification and identification of environmental microorganisms remains limited by the lack of reference spectra in current databases. In addition, the interpretation of the classical dendrogram-based data representation is more difficult when the quantity of taxa or chemotaxa is larger, which implies problems of reproducibility between users.

Paecilosetin Derivatives as Potent Antimicrobial Agents from .

Fifty-seven entomopathogenic microorganisms were screened against human pathogens and subjected to mass spectrometry molecular networking based dereplication. BSNB-1250, shown to produce potentially novel biologically active metabolites, was grown on a large scale on potato dextrose agar, and paecilosetin () and five new analogues (-) were subsequently isolated. The structures of the new compounds were elucidated using 1D and 2D NMR.

Identification of Antimicrobial Compounds from -Associated Endophyte Using Molecular Network Approach.

The emergence of multidrug resistant bacterial pathogens and the increase of antimicrobial resistance constitutes a major health challenge, leading to intense research efforts being focused on the discovery of novel antimicrobial compounds. In this study, endophytes were isolated from different parts of plant (leaves, wood and latex) belonging to the Euphorbiaceae family and known to produce antimicrobial compounds, and chemically characterised using Molecular Network in order to discover novel antimicrobial molecules. One fungal endophyte extract obtained from latex showed significant antimicrobial activity with Minimal Inhibitory Concentration on methicillin-resistant at 16 µg/mL.