Anotação metabolômica de Diaporthe phaseolorum baseada na propagação de informação das redes moleculares

Abstract

Mass spectrometry is a key tool for the annotation, identification and structural elucidation of natural products. However, the annotation of molecules is a major challenge in metabolomics experiments based on undirected mass spectrometry, as the manual interpretation of the resulting data is time-consuming, so computational methods to accelerate this process are in high demand. To assist this process in large datasets, some algorithmic solutions have been proposed, such as the GNPS (Global Natural Products Social Networking) web platform that makes use of molecular networks as a tool for organizing and visualizing spectral datasets. However, new algorithms are still needed to improve the accuracy of the results or provide additional analysis resources, as many metabolites remain unannotated against experimental libraries due to the absence of consensus spectra. To increase substance annotation rates, in silico methods can be applied. One such tool is Network Annotation Propagation (NAP), which can be integrated into the GNPS molecular network workflow. In this work, the molecular network generated by GNPS for the fungus Diaporthe phaseolorum (Dp) was propagated with NAP, with the objective of expanding chemical knowledge regarding the metabolic profile of the fungus, resulting in the annotation of 19 molecules in the benzenoid molecular family. Among the 19 molecules, 3 nodes were chosen to be worked on and annotated, being node 18 with m/z 105.0694 (C8H8 [M+H]), annotated as styrene, node 48 annotated as 4-Alifenol with m/z 135.0807 (C9H10O [M+H]), and node 90 with m/z 165.0910 (C10H12O2 [M+H]) annotated as 3-(p-tolyl)propanoic acid. As demonstrated, NAP accelerates research in metabolomics and dereplication by providing putative annotations on MS/MS molecular networks even for MS/MS spectra without spectral library matching. However, we demonstrate that any new putative annotation must be examined and confirmed.