Folin ciocalteau phenol reagent

Hydroxypropyl methylcellulose E15 (HPMC E15; AnyCoat-C AN15^®) was purchased from Lotte Fine Chemical (Ulsan, Korea). Folin–Ciocalteau phenol reagent, gallic acid monohydrate ACS reagent (≥98.0%) and tryptic soy broth were purchased from Sigma-Aldrich (Saint Louis, MO, USA). Sodium bicarbonate (NaHCO₃) was purchased from Merck (Darmstadt, Germany). Sodium nitrate (NaNO₃) and aluminum chloride (AlCl₃) were purchased from Merck (Darmstadt, Germany). Sodium hydroxide (NaOH) was purchased from Ajax Finechem (Victoria, Australia). A brain heart infusion (BHI) broth powder was purchased from HiMedia (Mumbai, India). Clindamycin solution; Clinda-M, RPC^® (equivalent to 1% clindamycin base) was purchased from RPC International Co., Ltd. (Bangkok, Thailand).

Folin-Ciocalteau phenol reagent, gallic acid, potassium persulfate and radical scavenging assay reagents: 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2′-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Sodium carbonate, methanol, hydrochloric acid (12 N), sodium chloride, sodium dihydrogen phosphate, sodium hydrogen phosphate, potassium chloride, sodium acetate, formic acid, acetonitrile and methanol (for HPLC grade) were supplied by Fisher Scientific.

Raw tree nuts of 6 species (5 commercial and 1 wild) were used in this study. Commercial species were almonds (ALM; Prunus dulcis), pecans (PEC; Carya illinoinensis), pine nuts (Pinnus cembroides) of pink (PNP) and white (PNW) varieties, pistachios (PIS; Pistacia vera), and walnuts (WAL; Juglans regia). They were all purchased from local retailers. Emory oak acorns (EOA; Quercus emory) were collected from wild trees located in Cuitaca, Sonora Mexico (31°00′17″ N, 110°29′33″ W) in the period September–October 2018.
Pure (≥93%) standards (gallic acid, α–, γ–, and δ–tocopherol); doxorrubicin, Folin–Ciocalteau phenol reagent, dimethyl sulfoxide (DMSO), Dulbecco’s modified Eagle’s medium, fetal bovine serum (FBS), 3- (4,5-dimethylthiazol-2-yl) 2,5 diphenyltetrazolium bromide (MTT), sodium chloride (NaCl), sodium hydroxide (NaOH), trypan blue, trypsin-EDTA, sodium phosphate salts were purchased from Sigma-Aldrich (St. Louis, MO, USA). Non-essential amino acids, L-Glutamine (200 mM), penicillin-streptomycin from Gibco (Gibco, Austria). High-performance liquid chromatography (HPLC) and analytical-grade solvents (hexane, methanol, acetone, and isopropyl and isobutyl alcohol) were obtained from JT- Baker (Avantar Performance Materials SA de CV, Mexico).

Cellulose acetate (39.8% weigth acetyl content. Mn ca. 30.000) was supplied by Aldrich. Reagent-grade absolute ethanol, quercetin dihydrate, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2ʹ-azinobis(3-ethylbenzothiazoline-6-sulphonate) (ABTS), Folin Ciocalteau phenol reagent, anhydrous sodium carbonate, gallic acid, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), and triethyl citrate (>99%) (TEC) were purchased from Sigma Aldrich Quimica S.A. (Santiago, Chile). Red onions were bought at a local supermarket in Santiago, Chile. Owing to avoiding differences in batches, the starting materials were all bought at the same time.

Citric acid, oxalic acid, lactic acid, ascorbic acid, kojic acid, MgCl₂, CaCl₂, ZnCl₂, NaCl, KCl, catechol, guaiacol, hydrogen, peroxide, trichloroacetic acid, poly(vinylpyrrolidinone) (PVP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), AlCl₃, NaOH, NaNO₂, linoleic acid, ferrosine, FeCl₂, FeCl₃, K₃[Fe(CN)₆], α-amylase (52.7 U/mg), lipooxigenase (50 kU/mg), pancreatin (4 × UPS), pepsin (541 U/mg), bile extract, and Folin–Ciocalteau phenol reagent were purchased from Sigma-Aldrich (Poznan, Poland). Nutrient agar, MRS agar, yeast extract, chloramphenicol, VRBL, and other chemicals used for microbiological media were purchased from TL Ltd. (Łódź, Poland). All other chemicals were of analytical grade.