Acetonitrile

A commercial yoghurt starter culture (YOFLEX^®—consisting of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) and three probiotic strains (Lacticaseibacillus rhamnosus LGG, Lacticaseibacillus casei 431, Bifidobacterium animalis subsp. lactis BB-12) were kindly supplied by Chr. Hansen, Bayswater, VIC, Australia. Powdered skim milk (Australian instant skim milk powder, Coles) was obtained from a local supermarket in Melbourne, VIC, Australia. Pancreatin was purchased from Alfa Aesar (Ward Hill, MA, USA). Mangiferin, pyrogallol, gallic acid, caffeic acid, 3-hydroxy phenyl acetic acid, 3-(2-hydroxyphenyl) propionic acid, porcine pepsin, α-amylase from aspergillus oryzae, p-nitrophenyl-α-d-glucopyranoside, bile salts, LC-MS grade formic acid, acetic acid, 4-methyl valeric acid, guar, casein, tryptone, cysteine HCl, peptone, mucin, pectin, potato starch, yeast extract, and MRS agar were acquired from Sigma–Aldrich (Castle Hill, NSW, Australia). Sodium carbonate (anhydrous), HCl, NaHCO₃, NaOH, (NH₄)₂CO₃, KCl, NaCl, KH₂PO₄, MgCl₂(H₂O)₆, CaCl₂, K₂HPO₄, Na₃PO₄, MgSO₄.7H₂O Tween 80, orthophosphoric acid, acetonitrile, and methanol of HPLC grade were acquired from Chem-supply Pty Ltd. (Melbourne, VIC, Australia).

All reagents were used as received unless otherwise specified, all organic solvents utilised were of analytical grade, and MilliQ^TM water (Merck, Melbourne, Australia) was used. Potassium tetrachloroplatinate (K₂PtCl₄) was acquired from Precious Metals Online. 1S,2S-Diaminocyclohexane (SSDACH, 98%), 1,10-phenanthroline (Phen), 5,6-dimethyl-1,10-phenanthroline (56Me₂Phen), silver nitrate, N,N′-dicyclohexylcarbodiimide (DCC), N-(3-Dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC-HCl), N-hydroxysuccinimide (NHS), indomethacin and aspirin were purchased from Sigma-Aldrich, Sydney, NSW. Sep-Pak^® C18 columns were obtained from Waters, Australia. Methanol, diethyl ether, ethyl acetate, dichloromethane (DCM), dimethyl formamide (DMF), dimethyl sulfoxide (DMSO) and acetonitrile (ACN) were acquired from Chem-Supply, Adelaide, Australia. Hydrogen peroxide (H₂O₂) (30%) was purchased from VWR chemicals, Philadelphia, United States. Potassium iodide (KI) was obtained from Merck, Melbourne, Australia. Ultra-pure HNO₃ (69%) was acquired from Choice Analytical, Sydney, Australia. The certified reference standard that was used for the ICP-MS experiments was purchased from High-Purity Standards, North Charleston, United States. The deuterated solvents deuterium oxide (D₂O, 99.9%) and d₆-dimethyl sulfoxide (DMSO-d₆, 99.9%) were obtained from Novachem, Melbourne, Australia.