Milli q purification system

Analytical grade ethanol (EtOH), MS grade formic acid (HCOOH), 6-hydroxy-2,5,7,8-acid tetramethylcroman-2-carboxylic acid (Trolox), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and the reference standards of isoquercitrin and rutin were provided by Merck Chemicals (Milan, Italy). MS grade acetonitrile and water were purchased from Romil (Cambridge, UK). Ultrapure water (18 MΩ) was prepared using a Milli-Q purification system (Millipore, Bedford, TX, USA).
Pinocembrin (L29), licoflavanone (L36), glabranin (L46), dihydro-3,3′,4′-trihydroxy-5-O-prenylstilbene (L33), and dihydro-3,5,4′-trihydroxy-4,5′-diprenylstilbene (L44) were purified by RP-HPLC prepared from G. glabra exudate and characterized by 1D- and 2D-NMR (purity ≥ 96% from HPLC). Finally, vicenin-2 was previously isolated from natural sources [30 (link)].

Methanol was provided by VWR (Barcelona, Spain), while sodium bicarbonate, acetate sodium, galic acid, and hydrochloric acid (HCl) were acquired from Merck (Darmstad, Germany). The ABTS (2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt was obtained from Amresco (Solon, OH, USA). 2,4,6-Tri(2-pyridyl)-s-triazine (TPTZ), and iron (III) chloride for the ferric-reducing power (FRAP) assay was from Fluka Chemicals (Fluka Chemicals, Madrid, Spain). Trolox ((±)-6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid), Folin–Ciocalteu reagent, all phenolic compounds, diethyl ether, Methanol, α-amylase from human saliva (A1031), pepsin from porcine gastric mucosa (P6887), pancreatin from porcine pancreas (P7545), bile salts (B8756), sodium dodecyl sulfate (SDS), o-phthaldialdehyde (OPA), DL-dithiothreitol (DTT), L-serine, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (HEPES), tert-butylhydroperoxide (t-BOOH), the cell culture media, and cell culture-grade chemicals were from Sigma-Aldrich (Sigma-Aldrich, St. Louis, MO, USA). The chemicals were all of high purity or analytical reagent grade. Bi-distilled deionized water (Milli-Q purification system, Millipore, Bedford, MA, USA) was used. Ingredients for biscuits’ preparation were purchased from local supermarkets.

Several groups of pharmaceuticals were studied
(Table 1). Water was
purified using
a Milli-Q purification system from Millipore (Nottingham, U.K.). Methanol,
formic acid (>95%), HCl (concentrated), 1 M NaOH, 1 M NH₄OH, NH₄F, and 2-propanol were purchased from Sigma-Aldrich
(U.K.) and Fisher (U.K.). All solvents used were of high-performance
liquid chromatography (HPLC) grade or higher. All glassware was deactivated
using a 5% (v/v) dimethyldichlorosilane (DMDCS) in toluene (Sigma-Aldrich,
U.K.) to prevent losses from analyte sorption according to the procedure
described elsewhere.^{20 (link)}

Hexanal (≥99%), (E)-2-hexenal (98.0%), benzaldehyde (>99%), 1-octen-3-ol (98%), 2-pentyl-furan (98%), D-limonene (≥99%), benzeneacetaldehyde (95%), linalool (98%), L-borneol (98%), epoxylinalol (>98%), methyl salicylate (≥99 %), β-cyclocitral (95%), (3Z)-3-hexenyl 2-methylbutanoate (98%), 1-methyl-naphthalene (98%), geranic acid (90%), n-hexyl caproate (≥98%), dihydroactinidiolide (98%), and (E)-nerolidol (95%) were purchased from Macklin (Shanghai, China). linalool oxide I (99%), linalool oxide II (96%), caryophyllene (90%), geranyl acetone (99%), and n-alkanes solution (C₈-C₃₂) were purchased from J&K Chemical (Beijing, China). Hexanoic acid (≥99.5%), phenylethyl alcohol (≥99%), α-terpineol (>95%), (Z)-geraniol (>98%), (E)-geraniol (≥99%), (E)-2-decenal (95%), α-ionone (≥90%), β-ionone (97%) and butylated hydroxytoluene (>99.7%) were purchased from Aladdin (Shanghai, China). Safranal (90%), theaspirane (≥95%), (E)-β-damascenone (≥95%), and dihydro-β-ionone (≥90%) were purchased from Bidepharm (Shanghai, China). Sodium chloride (99.5%, analytical grade). Water used in this study was purified by Milli-Q purification system (Millipore, Bedford, MA, USA).

3,4,5-trihydroxybenzoic acid (GA), 3,5-dihydroxybenzoic acid (3,5-DHBA), 3,4-dihydroxybenzoic acid (PCA), 5-caffeoylquinic acid (5CQA), 2,5-dihydroxybenzoic acid (2,5-DHBA), catechin (Cat), 4-caffeoylquinic acid (4CQA), p-hydroxybenzoic acid (pHBA), vanillic acid (VA), caffeic acid (CA), syringic acid (SyA), m-hydroxybenzoic acid (mHBA), 2,6-dihydroxybenzoic acid (2,6-DHBA), cumaric acid (CuA), sinapic acid (SA), ferulic acid (FA), rutin (Ru), myricitrin (My), quercetin-3-O-glucoside (Q3G), kampferol-3-O-rutinoside (K3R), salicylic acid (SaA), hesperidin (He), quercetin (Q), kampferol (K), isoxanthohumol (IsoX), xanthohumol (X), formic acid, and dichloromethane, were purchased from Sigma-Aldrich (Milano, Italy). HPLC-grade acetonitrile and methanol were Carlo Erba (Milano, Italy); HPLC-grade water was prepared with the Milli-Q purification system (Millipore, Vimodrone, Italy).

Methylene chloride (Optima Grade) and acetonitrile (HPLC Grade) were obtained from Fisher Scientific (San Jose, CA, USA). Ethanol (190 proof, USP Grade) was obtained from Pharmco Products (Brookfield, CT, USA). Formic acid (Reagent Grade) and anthracene-d10 (CAS No. 1719-06-8, 98% isotopic purity) were obtained from Sigma-Aldrich (Milwaukee, WI, USA). Distilled and deionized water was prepared in-house by double distillation in a glass-lined still followed by deionization and activated carbon filtration in a Millipore Milli-Q purification system.

Nine commercially available
standard compounds
were used for quantification purposes: 2-methoxyphenol (guaiacol,
GUA), pyrocatechol (catechol, CAT), pyrogallol (GAL), 4-nitroguaiacol
(4NG), 2-methoxy-5-nitrophenol (5-nitroguaiacol, 5NG), 2-methoxy-6-nitrophenol
(6-nitroguaiacol, 6NG, Key Organics/BIONET, U.K.), 6-methoxy-2,4-dinitrophenol
(4,6-dinitroguaiacol, (4,6DNG), AKos GmbH, Germany), 4-nitrocatechol
(4NC), and 3,5-dinitrocatechol (DNC). Purity of all standards was
≥95%. GUA was also used as a precursor compound in the aerosol
chamber experiments. Additionally, nitropyrogallol was synthesized
in an aqueous-phase photoreactor (for details see Supporting Information (SI)). Liquid chromatography (LC) and
liquid chromatography–mass spectrometry (LC–MS) grade
solvents and ultrapure water supplied by a Millipore Milli-Q purification
system were used for solution preparation, extraction, and mobile-phase
preparation.