Identification and dereplication of endophytic Colletotrichum strains by MALDI TOF mass spectrometry and molecular networking

Morgane Barthélemy , Vincent Guerineau , Grégory Genta-Jouve , Mélanie Roy (1) , Jérôme Chave (1) , Régis Guillot , Léonie Pellissier , Jean-Luc Wolfender (2) , Didier Stien (3) , Véronique Eparvier (4) , David Touboul (4)

1 EDB - Evolution et Diversité Biologique
2 UNIGE - Université de Genève = University of Geneva
3 LBBM - Laboratoire de Biodiversité et Biotechnologies Microbiennes
4 ICSN - Institut de Chimie des Substances Naturelles

The chemical diversity of biologically active fungal strains from 42 Colletotrichum, isolated from leaves of the tropical palm species Astrocaryum sciophilum collected in pristine forests of French Guiana, was investigated. The collection was first classified based on protein fingerprints acquired by matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) correlated with cytotoxicity. Liquid chromatography coupled to high-resolution tandem mass spectrometry (LC-HRMS/MS) data from ethyl acetate extracts were acquired and processed to generate a massive molecular network (MN) using the MetGem software. From five Colletotrichum strains producing cytotoxic specialized metabolites, we predicted the occurrence of peptide and cytochalasin analogues in four of them by MN, including a similar ion clusters in the MN algorithm provided by MetGem software. Chemoinformatics predictions were fully confirmed after isolation of three pentacyclopeptides (cyclo(Phe-Leu-Leu-Leu-Val), cyclo(Phe-Leu-Leu-Leu-Leu) and cyclo(Phe-Leu-Leu-Leu-Ile)) and two cytochalasins (cytochalasin C and cytochalasin D) exhibiting cytotoxicity at the micromolar concentration. Finally, the chemical study of the last active cytotoxic strain BSNB-0583 led to the isolation of four colletamides bearing an identical decadienamide chain.

Domaines: Autre

Morgane Barthélemy, Vincent Guerineau, Grégory Genta-Jouve, Mélanie Roy, Jérôme Chave, et al.. Identification and dereplication of endophytic Colletotrichum strains by MALDI TOF mass spectrometry and molecular networking. Scientific Reports, 2020, 10, pp.19788. ⟨10.1038/s41598-020-74852-w⟩. ⟨hal-03103617v1⟩