Dicaffeoylquinic acid

The compounds 2,2′-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), methanol acetic acid, phloroglucinol, β-cyclodextrin, and K₂S₂O₅ were purchased from Sigma-Aldrich (Steinheim, Germany). On the other hand, (−)-epicatechin, (+)-catechin, procyanidin B2, chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, caffeic acid, dicaffeoylquinic acid, p-coumaric acid, myricetin, isoquercitrin, cyanidin-3-O-galactoside, and cyanidin-3-O-glucoside were purchased from Extrasynthese (Lyon, France). Acetonitrile for ultra-performance liquid chromatography (UPLC; Gradient grade) and ascorbic acid were from Merck (Darmstadt, Germany). Yeasts S. cerevisiae and S. bayanus were purchased from Eaton company (Sandomierz, Poland).

The compounds 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), methanol, malic acid, oxalic acid, citric acid, isocitric acid, quinic acid, ferulic acid, galacturonic acid, and succinic acid were purchased from Sigma-Aldrich (Steinheim, Germany). On the other hand, (−)-epicatechin, (+)-catechin, procyanidin B2, chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, caffeic acid, dicaffeoylquinic acid, p-coumaric acid, myricetin, isoquercitrin, cyanidin-3-O-galactoside, and cyanidin-3-O-glucoside were purchased from Extrasynthese (Lyon, France). Acetonitrile for ultra-performance liquid chromatography (UPLC; Gradient grade) and ascorbic acid were from Merck (Darmstadt, Germany).

Phenolic acid standards, i.e., 5-O-caffeoylquinic acid (5-CQA), 4-O-caffeoylquinic acid (4-CQA) as well as 3-O-caffeoylquinic acid (3-CQA) were purchased from TRANS MIT GmbH (Giessen, Germany). Caftaric acid was bought from Cayman Chemical Co. (Ann Arbor, MI, USA). Dicaffeoylquinic acid, p-coumaric acid and ferulic acid were purchased from Extrasynthese (Genay, France), whereas Folin-Ciocalteu reagent, sodium hydroxide,6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid diammonium salt (ABTS), 1,1-diphenyl-2-picrylhydrazyl radical DPPH, sodium hydrogen sulfite (NaHSO₃) and formic acid were purchased from Sigma-Aldrich Chemical Co. (Steinheim, Germany). Acetonitrile was bought from POCh (Gliwice, Poland). All reagents were of analytical grade.