Iron 3 chloride

SP4^TM is a patent pending formulation (PCT/US2022/021087) composed by a mixture of plant extracts containing a high content of type-A proanthocyanidins and other polyphenols. The origin of the plants is included in the relevant patent (PCT/US2022/021087).
Dulbecco’s Modified Eagle Medium (DMEM) was purchased from Thermo Fisher (Waltham, MA USA), cell lysis solution and luciferin were purchased from BPS Bioscience (San Diego, CA, USA), HepG2 human hepatocyte carcinoma, 85,011,430 cell lines, Fetal Calf Serum (FCS), ethanol (95%), Folin–Ciocolteu reagent, sodium carbonate, sodium nitrite, aluminum chloride, sodium hydroxide, potassium chloride, sodium acetate, potassium ferricyanide (99.8%), 1,1-diphenyl-2-picryl-hydrazil stable radical (DPPH^•) (>98%), ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid) (98%), and phenolic compounds standards (including PAC-A2) were purchased from Sigma-Aldrich (Milan, Italy). The c-PAC standard was provided by Complete Phytochemical Solutions (Cambridge, USA). The 4-(dimethylamino)-cinnamaldehyde (DMAC), hydrochloric acid, acetic acid, acetone, acetonitrile, formic acid, potassium persulfate, 2,4,6-Tris(2-pyridyl)-s-triazine (TPTZ), and iron(III) chloride were purchased from VWR International (Radnor, PA, USA).

Iron(III) chloride (FeCl₃, 27% w/v) was from VWR Chemicals (Fontenay-sous-Bois, France). Iron(II) chloride tetrahydrate (FeCl₂·4H₂O, ≥99%), ammonium hydroxide (NH₄OH, 25% v/v), nitric acid (HNO_3, 65% w/w), iron(III) nitrate nonahydrate (Fe(NO₃)₃)·9H₂O, ≥98%), citric acid (C₆H₈O₇, ≥99.5%), succinic anhydride (C₄H₄O₃, ≥99%), sodium phosphate monobasic (NaH₂PO₄, ≥99%), oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH, ≥99%), sucrose (C₁₂H₂₂O₁₁, ≥99.5%), Ethylenediamine (NH₂CH₂CH₂NH₂, ≥99.5%), N-hydroxysuccinimide (C₄H₅NO₃, ≥98%), N-(3-Dimethylaminopropyl)-N’-ethylcarbodiimide (C₈H₁₇N₃·HCl, ≥98%), p-nitrophenyl butyrate (C₁₀H₁₁NO₄, ≥98%), methyl dl mandelate (C₆H₅CH(OH)COOCH₃, ≥97%), methyl (R)-(−)-mandelate (C₆H₅CH(OH)COOCH₃, ≥99%), methyl (S)-(+)-mandelate (C₆H₅CH(OH)COOCH₃, ≥99%) were from Sigma-Aldrich (Saint Louis, MO, USA). Lipase from Candida antartica fraction B (Lipozyme^® CALB) was a kind gift gratefully received from Novozymes (Bagsvaerd, Denmark).

Acetone and ethanol used to prepare propolis extracts were purchased from Avantor Performance Materials (Gliwice, Poland). All phenol standards (apigenin, chrysin, quercetin, galangin, myricetin, kaempferol, rutin, genistein, naringenin, epicatechin, pinocembrin, pinobanksin, pinostrobin, catechin, caffeic acid, ferulic acid, coumaric acid, sinapinic acid, cinnamic acid, vanillic acid, syringic acid, chlorogenic acid, and p-hydroxybenzoic acid) and chemicals (methanol, acetonitrile, and formic acid) used in UPLC analysis were purchased from Sigma Aldrich (Steinheim, Germany). Chemicals for the determination of antioxidant activity and cytotoxicity of the propolis extracts in human erythrocytes (dimethyl sulfoxide (DMSO), potassium ferricyanide, trichloroacetic acid, iron(III) chloride, iron(II) chloride, ferrozine, glucose, paraformaldehyde, glutaraldehyde) were purchased from Avantor Performance Materials (Gliwice, Poland). Butylated hydroxyltoluene (BHT), Trolox, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azobis-(2-methylpropionamidine) dihydrochloride (AAPH), poly-l-lysine, ethylenediaminetetraacetic acid (EDTA), phosphate-buffered saline (PBS buffer: 137 mM NaCl, 2.7 mM KCl, 10 mM NaH₂PO₄, 1.76 mM KH₂PO₄)), and potato dextrose agar (PDA) were purchased form Sigma Aldrich (Steinheim, Germany).