Quinic acid

Rosmarinic acid, apigenin-7-O-glucoside, luteolin-7-O-glucoside, eriodictyol-7-O-glucoside, luteolin-8-C-glucoside, quinic acid, caffeic acid, and t-5-O-caffeoylquinic acid were obtained from Extrasynthese (Genay Cedex, France). Gallic acid and nisin were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Folin-Ciocalteu reagent, Na₂CO₃, formic acid, and ethanol were purchased from Panreac (Barcelona, Spain). n-hexane, methanol, and acetonitrile with HPLC purity were purchased from Lab-Scan (Lisbon, Portugal). Mueller-Hinton agar was obtained from VWR, Prolabo Chemicals, West Chester, PA, USA. Water was treated in a Direct-Q^® water purification system (Merck Life Science, Germany).

Analytical standards of quinic acid (QNA), 3-O-caffeoylquinic acid (3-CQA), 4-O-caffeoylquinic acid (4-CQA), 5-O-caffeoylquinic acid (5-CQA), quercetin-3-O-rutinoside (QURU), quercetin-3-O-glucoside (QUGL), and quercetin-3-O-galactoside (QUGA) were purchased from Extrasynthese (Genay Cedex, France), whereas protocatechuic acid (PRCA), gallic acid (GA), caffeic acid (CA), and p-coumaric acid (pCA) were obtained from Sigma-Aldrich (Steinheim, Germany). 1-caffeoylquinic acid (1-CQA), 3,5-dicaffeoylquinic acid (3,5-DCQA), 3,4-dicaffeoylquinic acid (3,4-DCQA), 4,5-dicaffeoylquinic acid (4,5-DCQA), and vicenin-2 were obtained from Carbosynth (Berkshire, UK). All other reagents were of HPLC or LC-MS grade.

Rosmarinic acid and the 7-O-glucoside derivatives of apigenin, luteolin, eriodyctiol, quinic acid, caffeic acid, 5-O-caffeoylquinic acid, 4-O-hydroxybenzoic acid, salvianolic acid B, caffeic acid, ferulic acid, and 4-O-coumaric acid were obtained from Extrasynthese (Genay Cedex, France). Trolox, sulforhodamine B (SRB), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, acetic acid, ellipticine, trypan blue, trichloroacetic acid (TCA), Tris, lipopolysaccharide (LPS), carnosol, nisin, ascorbic acid, and butylated hydroxyanisole (BHA) were obtained from Sigma Chemical Co (St Louis, MO, USA). Fetal bovine serum (FBS), L-glutamine, trypsin-ethylenediaminetetraacetic acid (EDTA), penicillin/streptomycin solution (100 U/mL and 100 mg/mL, respectively), Roswell Park Memorial Institute (RPMI) 1640 Medium and Dulbecco’s Modified Eagle Medium (DMEM) were from Hyclone (Logan, Utah, UT, USA). The Griess reagent system was purchased from Promega Corporation (Madison, WI, USA). Mueller-Hinton agar was from VWR (Prolabo Chemicals, USA); formic acid and ethanol was from Panreac (Barcelona, Spain). n-Hexane, methanol, and acetonitrile were purchased from Lab-Scan (Lisbon, Portugal). Purified water was obtained from a Direct-Q^® water purification system (Merck Life Science, Darmstadt, Germany).