Seasonal changes in the metabolic fingerprint of Juniperus communis L. berry extracts by 1H NMR-based metabolomics

The economically important crop Juniperus communis (Cupressaceae) is a coniferous evergreen shrub or tree distributed throughout the temperate zone of the Northern hemisphere. Its dried bluish-black cones, known as juniper berries, are used as flavoring agent in foodstuffs and spirits, while their extracts are widely employed in medicine for their antimicrobial, antifungal, and anticancerogenous activity. Despite their medicinal and commercial values, no systematic studies on the metabolome of J. communis berries have been carried out so far. We have investigated the metabolic profiles of J. communis berries by NMR spectroscopy and statistical analysis, aiming at monitoring their seasonal variation. Principal components analysis and partial least square discriminant analysis of proton NMR spectra provided a clear class separation according to the ripeness and the harvest season, with well-defined metabolic profiles for each class. The results show that the Juniperus metabolome is dominated by 26 metabolites including sugars, amino acids, organic acids and diterpenes. The specificity of NMR profiles offers a powerful tool for assessing the molecular determinants characterizing the quality of this commercially important crop.