Rosamarinic acid

Standard (purity > 98%) flavonoids and phenolic acids including quinic acid, gallic acid, protocatechuic acid, epicatechin, 5-caffeoylquinic acid, catechin, p-cumaric acid, apigenin-7-O-glucoside, ferulic acid, naringin, rutin, quercetin 3 galattoside, hesperidin, rosamarinic acid, kaempferol 3 glucoside, ellagic acid, diosmin, genistein, isorhamnetin 3 rutinoside, myricetin, daidzein, quercetin, naringenin, gallic acid, luteolin, and apigenin were provided from Sigma-Aldrich (Milan, Italy). For the antioxidant experiments, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), gallic acid, potassium persulphate, 2,3,5-triphenyltetrazolio chloride (TPTZ), 1,1-diphenyl-2-picrylhydrazyl (DPPH), anhydrous ferric chloride, sodium acetate, and hydrochloric acid were provided from Sigma-Aldrich. Standards and enzymes used to simulate GI process were: pepsin, bile salt, α-amylase, pancreatin, bacterial protease from Streptomyces griseus (Pronase E), Viscozyme L and pancreatin were provided from Sigma-Aldrich. Moreover, Megazyme^® phytic acid assay kit, ammonium molybdate, potassium persulfate, calcium chloride, sodium carbonate, hydrochloric acid, acetate buffer, ferric chloride (FeCl₃) and sodium chloride were provided from Sigma-Aldrich.

The deionized water used for the sample extraction was purchased from Millipore (Bedford, MA, USA), whereas the methanol, formic acid (FA), and water (LC–MS grade) used for the chromatography were provided by Carlo Erba reagents (Milan, Italy). The polyphenol standards (purity > 98%), namely protocatechuic acid, gallic acid, quinic acid, apigenin-7-O-glucoside, p-coumaric acid, catechin, epicatechin, chlorogenic acid, rosamarinic acid, hesperidin, quercetin-3-galattoside, rutin, naringin, ferulic acid, apigenin, luteolin, gallic acid, naringenin, quercetin, daidzein, myricetin, isorhamnetin-3-rutinoside, genistein, diosmin, and ellagic acid kaempferol-3-glucoside were purchased from Sigma-Aldrich (Milan, Italy). In order to perform antioxidant tests, hydrochloric acid, 1,1-diphenyl-2-picrylhydrazyl (DPPH), potassium persulphate, 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) were provided by Sigma-Aldrich (Milan, Italy). The enzymes and standards used in the simulated GI, namely pancreatin, α-amylase (1000–3000 U/mg solid) from human saliva, bile salt, pepsin (≥2500 U/mg solid) from porcine gastric mucosa, Pronase, and Viscozyme L., were purchased from Sigma-Aldrich (Milan, Italy).