Detailed Phytochemical Characterization of Bergamot Polyphenolic Fraction (BPF) by UPLC-DAD-MS and LC-NMR.

Bergamot ( Citrus bergamia) is cultivated in Southern Italy almost exclusively to produce the prized essential oil, a top note in several perfumes. The juice of bergamot, until recently poorly studied, is the object of a growing scientific interest due to its claimed activity to treat metabolic syndrome. The aim of this investigation was a detailed characterization of bergamot juice polyphenolic fraction (BPF) based on a UPLC-DAD-MS analysis complemented by preparative chromatographic separations, followed by NMR characterization of the isolated compounds. The combination of these techniques efficiently covered different classes of secondary metabolites, leading to the identification of 39 components, several of which had never been reported from bergamot. One of them, bergamjuicin (35), is a new flavanone glycoside, whose structure has been determined by MS and NMR techniques. The reported results could provide a guide for future routine analyses of BPF, a material of great nutraceutical and industrial interest.