Untargeted metabolomics is a powerful tool for investigating chemistry of complex biological systems but its utility is compromised by the presence of uninformative features and the limited efficiency of currently available prioritization tools. More effective filtering and prioritization tools are required to address the challenges of large untargeted metabolomics datasets. Here, we introduce MPACT (Metabolomics Peak Analysis Computational Tool), a new mass spectrometry data analysis platform employing filtering based on multiple modalities, statistical techniques incorporating multilevel replication, and interactive data visualization. We demonstrate application of MPACT to uncover hidden effects of the rare earth element (REE) cerium on tunicate-associated bacterium Streptomyces sp. PTY087I2. Using this method, we have identified key autoregulators, siderophores. and a suite of structurally diversified granaticins, culminating in characterization of two thiolated compounds including a new cysteine derivative, granaticin C, and granaticin D, recently described as mycothiogranaticin A. MPACT is readily adaptable to investigation of other systems.
Includes supplementary methods, data, figures, and tables.