Atractylosides, chlorogenic acids and antioxidant capacity of raw Arabica green coffee beans (AGCB) used by regular and spontaneous dieters to supports body weight loss and slimming

Abstract

Using DPPH, ABTS and Folin-Ciocalteu procedures [1] the antioxidant capacity was characterized of fresh infusions of the raw AGCB distributed in Poland and originating from Central and South America. Next, UHPLC-TOF-MS/MS analyses of all infusions and MeOH extracts of raw AGCB were made using a Waters ACQUITY UPLC TabMode system interfaced with a Bruker microOTOF-Q mass spectrometer with an ESI source operating in negative mode at 150 °C and 4.5 kV with N2 nebulisation at 1.2 bar and a dry gas flow at 6 mL/min. An Agilent Poroshell 120EC-C18 column (2.1 × 150, 2.7 µm) was used operating at 0.6 mL/min flow rate with a mobile phase consisted of a linear gradient of 0.1% formic acid in water (A) and 0.1% formic acid in AcN (B), mixed by increasing eluate B in the range 5 – 90% from 0 – 20 min and followed by a split of column effluent flow 3:2 before the ESI ion source was used. MSMS spectra were analyzed with a Bruker Compass Data Analyzer v.4. The atractyligenin derivatives, i.e. 2-O-beta-D-glucopyranosyl-carboxyatractyligenin (m/z 525) (1), 2-O-(2'-O-isovaleryl-beta-D-glucopyranosyl)-carboxyatractyligenin (m/z 608) (2) and 3'-O-beta-D-glucopyranosyl-2'-O-isovaleryl-2-beta-(2-desoxy-carboxyatractyligenin)-beta-D-glucopyranoside (m/z 771) (3), were identified in the MeOH extracts of the raw but not milled AGCB from Colombia. Only compound 1 with a high inhibitory activity of adenine nucleotide translocase (ANT) [2] was confirmed by MSMS in the infusions of this AGCB sample. This indicates that some atractylosides in raw AGCB were hydrolyzed by hydrothermal treatment [3]. Compounds 1 and 3 with, respectively, significant and non-significant ANT inhibition were recently detected in the AGCB [2], but glucoside 2 was identified here for the first time.