Procyanidin b3

Hot water-extracted PBE was obtained from Nutrapharm Ltd. (Yongin, Republic of Korea). SCOP hydrobromide, protocatechuic acid, (+)-catechin, procyanidin B1, procyanidin B2, procyanidin B3, taxifolin, caffeic acid, quercetin, (−)-epicatechin, Hank’s Balanced Salts, 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), 2-thiobarbituric acid, trichloroacetic acid, 1,1,3,3-tetramethoxypropane, acetylthiocholine, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), DL-2-amino-5-phosphonovaleric acid (DL-AP5), malondialdehyde tetrabutylammonium salt, and 5,5′-dithio-bis-(2-nitrobenzoic acid) were purchased from Sigma-Aldrich Co., LLC (St. Louis, MO, USA). Lysis buffer was obtained from Noble Bio, Inc. (Hwaseong, Republic of Korea). Protease inhibitor cocktail was purchased from GenDEPOT (Barker, TX, USA). Superoxide dismutase (SOD) assay kit (DG-SOD400) and catalase assay kit (DG-CAT400) were purchased from DoGenBio Co., Ltd. (Seoul, Republic of Korea). Horse serum and penicillin-streptomycin were purchased from Biowest (Nuaillé, France) and Gibco BRL (Grand Island, NY, USA), respectively. LC-MS grade water and acetonitrile were purchased from Merck (Darmstadt, Germany).

High purity standards for the qualitative-quantitative determination of carotenoids were purchased from CaroteNature (Lupsingen, Liestal, Switzerland). Alpha and β-tocotrienols were purchased from Cayman Chemicals (Ann Arbor, MI, USA). High-performance liquid chromatography (HPLC) grade solvents, α- and β-tocopherols, ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), potassium persulfate were bought from Sigma-Aldrich (Milan, Italy). Standards for phenolic acids and flavonoids qualitative-quantitative analyses (p-hydroxybenzoic acid, vanillic acid, syringic acid, p-coumaric acid, sinapic acid, ferulic acid, 3,5-dichloro-4-hydroxybenzoic acid, procyanidin B2, procyanidin B3, catechin, epicatechin, luteolin, kaempferol-7-O-neohesperidoside) were purchased from Sigma-Aldrich, Gillingham, UK.

All chemicals, reagents, and standards used were either analytical or LC-MS grade reagents. The water was treated in a Milli-Q water purification system (Millipore, Bedford, MA, USA) before use. Gallic acid (purity ≥ 98% HPLC), procyanidin B1 (purity ≥ 90% HPLC), procyanidin B2 (purity ≥ 90% HPLC), procyanidin B3 (purity ≥ 95% HPLC), procyanidin C1 (purity ≥ 90% HPLC), catechin (purity ≥ 98% HPLC), chlorogenic acid (purity ≥ 95% HPLC), neochlorogenic acid (purity ≥ 98% HPLC), caffeic acid (purity ≥ 98% HPLC), vanillic acid (purity ≥ 97% HPLC), syringic acid (purity ≥ 98% HPLC), p-coumaric acid (purity ≥ 98% HPLC), epicatechin (purity ≥ 98% HPLC), ferulic acid (purity ≥ 99% HPLC), rutin (purity ≥ 94% HPLC), naringenin (purity ≥ 95% HPLC), quercetin 3-O-glucoside (purity ≥ 98% HPLC), kaempferol 3-O-glucoside (purity ≥ 90% HPLC), quercetin (purity ≥ 98% HPLC) and reagents for in vitro studies were purchased from Sigma-Aldrich (Milan, Italy).