Isorhamnetin 3 o rutinoside

The sugar standards (glucose, fructose, sucrose, arabinose, isomaltose, raffinose, maltose, and panose) were purchased from Supelco/Sigma–Aldrich (St. Louis, MI, USA). Standards for organic acids (quinic acid, shikimic acid, galacturonic acid, fumaric acid, malic acid, maleic acid and citric acid) and polyols (sorbitol and mannitol) were purchased from Supelco/Sigma–Aldrich (St. Louis, MI, USA), while sodium acetate trihydrate and 50% sodium hydroxide solution were from Sigma–Aldrich (St. Louis, MI, USA). All aqueous solutions were prepared with ultrapure water (0.055 µS/cm) obtained using the Thermo Fisher (Waltham, MA, USA) TKA MicroPure water purification system. Polyphenol standards (gallic acid, chlorogenic acid, catechin, caffeic acid, aesculin, rutin, p-coumaric acid, hyperoside; isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside, kaempferol-3-O-glucoside, quercetin-3-O-rhamnoside, ellagic acid, quercetin, isorhamnetin) were purchased from Sigma–Aldrich (St. Louis, MI, USA).

Reagents of Mass Spectrometry grade, including acetonitrile, methanol, water, and formic acid, were purchased from Sigma Chemical Co. (St. Louis, MO, USA). Also, Folin–Ciocalteu’s phenol reagent was obtained from Sigma Chemical Co. Analyzed phenols included protocatechuic acid, m-hydroxybenzoic acid, chlorogenic acid, salicylic acid, caffeic acid, syringic acid, sinapic acid, ferulic acid, p-coumaric acid, m-coumaric acid, o-coumaric acid, gallic acid, o-hydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, trans-cinnamic acid, vanillic acid, benzoic acid, ellagic acid, vitexin, rutin, (+)-catechin, apigenin, kaempferol, orientin, naringenin, myricetin, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside, kaempferol-3-O-rutinoside, quercetin, and its derivativeswere purchased from Sigma Chemical Co. (St. Louis, MO, USA). Folin–Ciocalteu’s phenol reagent, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH), and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) were obtained from Sigma Chemical Co. (St. Louis, MO, USA).

Analytical and chromatographic grade reagents were used for this study: gradient-grade acetonitrile, MS-grade formic acid, neochlorogenic acid, cryptochlorogenic acid, quercetin 3-O-(6″-O-malonyl)-β-D-glucoside (quercetin 3-O-malonylglucoside hereinafter), isorhamnetin 3-O-rutinoside (Sigma-Aldrich GmbH, Steinheim, Germany), HPLC-grade 99.8% trifluoracetic acid, chlorogenic acid, HPLC-grade hyperoside, HPLC-grade isoquercitrin, HPLC-grade rutin, astragalin (Carl Roth GmbH, Karlsruhe, Germany), and 96.3% ethanol (Stumbras SC, Kaunas, Lithuania). The purified deionized water (18.2 mΩ/cm) was produced using a Millipore (Burlington, MA.,USA) water purification system.