Identification and quantification of major phenolic constituents in Juglans regia L. leaves: healthy vs. infected leaves with Xanthomonas campestris pv. juglandis using HPLC-MS/MS

The present study was designed to characterise and quantify the major phenolic constituents in healthy leaves infected with Xanthomonas campestris pv. juglandis. A comparison among six different cultivars: 'Fernor', 'Fernette', 'Franquette', 'Rubina', 'Sava' 'Krka', same agricultural, geographical climatic conditions, made. Liquid chromatography coupled a mass spectrometer (HPLC-MS/MS) used identify compounds. total of 52 compounds were identified based on spectra literature. Among them, 15 hydroxycinnamic acids, 6 flavanols, 2 flavones, 22 flavonols 7 naphthoquinones identified. Two flavones three reported for first time J. regia leaves. In addition, two naphthoquinones, which are play an active role process juglone formation, confirmed all cultivars. MS fragmentation, fragmented up MS6 fragments some cases both MS2 further fragmented, providing comprehensive data. Total analysed content (TAPC) (TPC) concentrations higher leaves, suggesting that phenols plant defence. case walnut bacterial blight, contents flavanols acids cultivars, they could key plant’s response this economically important disease.