Natural-product discovery

Bioactivity-Based Molecular Networking

A transferable natural-product discovery strategy that overlays quantitative bioassay results onto LC-MS feature abundance and MS/MS molecular networks to prioritize molecular families and individual features associated with biological activity.

Journal of Natural Products · 2018 · 10.1021/acs.jnatprod.7b00737

LC-MSUntargeted metabolomicsNatural-product discovery

What does this strategy enable?

Bioactivity-Based Molecular Networking adds an orthogonal biological evidence layer to molecular networking. Fractionated samples are profiled by LC-MS/MS and tested in a quantitative bioassay. Feature abundances across fractions are correlated with bioactivity, producing a bioactivity score that is mapped onto the molecular network. This allows active molecular families and candidate analogues to be prioritized before isolation while preserving molecular-network annotation and dereplication context.

Transferable workflow

Workflow

  1. 1

    Generate fractions and quantitative bioassay data

    Fractionate the bioactive extract or sample set and measure a quantitative biological response for the same fractions used for metabolomics.

  2. 2

    Acquire untargeted LC-MS/MS profiles

    Profile the fractions by LC-MS/MS so that feature abundance across fractions and fragmentation spectra are available.

  3. 3

    Detect and quantify features

    Process the LC-MS/MS data to generate aligned feature intensities across the fraction series.

  4. 4

    Calculate feature–bioactivity associations

    Correlate feature abundance across fractions with the quantitative bioassay response to calculate a bioactivity score for each feature.

  5. 5

    Build and annotate the molecular network

    Generate a molecular network from MS/MS similarity and attach the bioactivity scores as node attributes so active molecular families can be recognized in chemical context.

  6. 6

    Prioritize and validate active chemistry

    Select high-scoring features or molecular families for isolation, orthogonal structural work, and direct activity confirmation.

Connected resources

Tools used in this strategy

Evidence of reuse

Published implementations and adaptations

These papers applied, adapted, extended, benchmarked or formalized the Strategy after its originating publication. They are examples of precedent, not a ranking of software choices.

Application · Journal of Natural Products · 2024

Bioactivity-Based Molecular Networking-Guided Isolation of Epicolidines A-C from the Endophytic Fungus Epicoccum sp. 1-042

Used bioactivity-based molecular networking-guided fractionation in an endophytic fungal natural-product study to prioritize and isolate antibacterial polycyclic tetramic acids.

doi:10.1021/acs.jnatprod.4c00214

Application · Marine Drugs · 2020

Bioactive Molecular Networking for Mapping the Antimicrobial Constituents of the Baltic Brown Alga Fucus vesiculosus

Applied bioactive molecular networking to fractionated Fucus vesiculosus extracts, combining antimicrobial activity against MRSA with UPLC-QToF-MS/MS feature abundances, MZmine preprocessing, GNPS feature-based molecular networking, Pearson correlation scoring and Cytoscape visualization.

Navigator tools used: MZmine, GNPS, Cytoscape

doi:10.3390/md18060311

Strategy profile

Related objectives

Phenotype association, Molecular-family discovery, Dereplication

Components

Sample preparation, Chromatography, Data acquisition, Preprocessing and feature extraction, Molecular networking, Statistical analysis, Biological validation, Data and workflow sharing

Biological context

Broadly applicable

Ion mobility

Ion mobility not required

Scope and considerations

Designed for

  • Bioassay-guided natural-product discovery where the same fractions or samples have quantitative LC-MS feature data and biological activity measurements.
  • Prioritizing active analogues within molecular families before purification.

Important requirements

  • Reproducible quantitative bioassay values matched to metabolomics samples.
  • Sufficient variation in both feature abundance and bioactivity across the sample or fraction series.
  • The supplied implementation uses MZmine 2 or Optimus exports and an R script or R-kernel Jupyter notebook; check current export compatibility.

Considerations

  • Correlation between a feature and bioactivity is prioritization evidence, not proof that the feature causes the phenotype.
  • Coeluting or covarying metabolites can receive similar activity scores and require follow-up isolation or orthogonal validation.

Reusable resources

✓ Code available✓ Published method available

Publication

Nothias L-F, Nothias-Esposito M, da Silva R, et al. Bioactivity-Based Molecular Networking for the Discovery of Drug Leads in Natural Product Bioassay-Guided Fractionation. Journal of Natural Products 81, 758–767 (2018).

doi:10.1021/acs.jnatprod.7b00737

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