title: Metabolic Profiling and Classification of Propolis Samples from Southern Brazil: An NMR-Based Platform Coupled with Machine Learning.
abstract: The chemical composition of propolis is affected by environmental factors and harvest season, making it difficult to standardize its extracts for medicinal usage. By detecting a typical chemical profile associated with propolis from a specific production region or season, certain types of propolis may be used to obtain a specific pharmacological activity. In this study, propolis from three agroecological regions (plain, plateau, and highlands) from southern Brazil, collected over the four seasons of 2010, were investigated through a novel NMR-based metabolomics data analysis workflow. Chemometrics and machine learning algorithms (PLS-DA and RF), including methods to estimate variable importance in classification, were used in this study. The machine learning and feature selection methods permitted construction of models for propolis sample classification with high accuracy (>75%, reaching ∼90% in the best case), better discriminating samples regarding their collection seasons comparatively to the harvest regions. PLS-DA and RF allowed the identification of biomarkers for sample discrimination, expanding the set of discriminating features and adding relevant information for the identification of the class-determining metabolites. The NMR-based metabolomics analytical platform, coupled to bioinformatic tools, allowed characterization and classification of Brazilian propolis samples regarding the metabolite signature of important compounds, i.e., chemical fingerprint, harvest seasons, and production regions.
authors.affiliation: Plant Morphogenesis and Biochemistry Laboratory, Federal University of Santa Catarina , Florianópolis, SC, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Maraschin
authors.affiliation: Plant Morphogenesis and Biochemistry Laboratory, Federal University of Santa Catarina , Florianópolis, SC, Brazil.
authors.forename: Amélia
authors.initials: A
authors.lastname: Somensi-Zeggio
authors.affiliation: Plant Morphogenesis and Biochemistry Laboratory, Federal University of Santa Catarina , Florianópolis, SC, Brazil.
authors.forename: Simone K
authors.initials: SK
authors.lastname: Oliveira
authors.affiliation: Plant Morphogenesis and Biochemistry Laboratory, Federal University of Santa Catarina , Florianópolis, SC, Brazil.
authors.forename: Shirley
authors.initials: S
authors.lastname: Kuhnen
authors.affiliation: Plant Morphogenesis and Biochemistry Laboratory, Federal University of Santa Catarina , Florianópolis, SC, Brazil.
authors.forename: Maíra M
authors.initials: MM
authors.lastname: Tomazzoli
authors.affiliation: Plant Morphogenesis and Biochemistry Laboratory, Federal University of Santa Catarina , Florianópolis, SC, Brazil.
authors.forename: Josiane C
authors.initials: JC
authors.lastname: Raguzzoni
authors.affiliation: Brazilian Biosciences National Laboratory (LNBio-CNPEM/MCTI) , Campinas, São Paulo, Brazil.
authors.forename: Ana C M
authors.initials: AC
authors.lastname: Zeri
authors.affiliation: CEB-Centre Biological Engineering, University of Minho , Campus of Gualtar, Braga, Portugal.
authors.forename: Rafael
authors.initials: R
authors.lastname: Carreira
authors.affiliation: CEB-Centre Biological Engineering, University of Minho , Campus of Gualtar, Braga, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Correia
authors.affiliation: CEB-Centre Biological Engineering, University of Minho , Campus of Gualtar, Braga, Portugal.
authors.forename: Christopher
authors.initials: C
authors.lastname: Costa
authors.affiliation: CEB-Centre Biological Engineering, University of Minho , Campus of Gualtar, Braga, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Rocha
mesh_terms: D001938:Brazil; D005419:Flavonoids / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011429:Propolis / Q000737:chemistry*; D012621:Seasons
chemical_list: D005419:Flavonoids; D011429:Propolis