Cannabinol

All reagents were of analytical grade. Standards of Δ⁹-trans-tetrahidrocannabinol, cannabidiol, and cannabinol (solutions in methanol) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Acetonitrile, chloroform, and methanol were of HPLC grade (VWR, Radnor, PA, USA).
Intermediate stock standard solutions of the analytes (1 mg/mL) were prepared by diluting the commercial standards with Acetonitrile and kept at −20 °C until use. Working solutions were prepared by diluting the stock solutions with ultrapure water.

Gradient grade water, acetonitrile, chloroform, methanol, and formic acid were purchased from Merck Life Science (Milano, Italy). Cannabinoid reference standards dissolved in methanol, namely, cannabidivarin (CBDV, 1 mg/mL), cannabigerol (CBG, 1 mg/mL), cannabidiol (CBD, 1 mg/mL), cannabidiolic acid (CBDA, 1 mg/mL), cannabinol (CBN, 1 mg/mL), (–)-Δ9-tetrahydrocannabinol ((–)-Δ9-THC, 1 mg/mL), Δ9-tetrahydrocannabinolic acid ((–)-Δ9-THCA, 1 mg/mL), (–)-Δ8-tetrahydrocannabinol ((–)-Δ8-THC, 1 mg/mL), and cannabichromene (CBC, 1 mg/mL) with purity ≥ 99%, were purchased from Merck Life Science (Milano, Italy). Deuterated water (D₂O) 99.97 atom% of deuterium and 3-(trimethylsilyl)-propionic-2,2,3,3-d₄ acid sodium salt (TSP) were purchased from Euriso-Top (Saclay, France). Magnesium oxide (MgO), potassium phosphate monobasic (KH₂PO₄), and potassium phosphate dibasic (K₂HPO₄) 2,2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin–Ciocalteu reagent, gallic acid (GA), and sodium carbonate (Na₂CO₃) were purchased from Merck Life Science (Milano, Italy).

All solvents used for
UHPLC analyses were HPLC grade and were purchased from Merck Life
Science (Milan, Italy) and Carlo Erba Reagents (Milan, Italy). Cannabinoid
reference standards dissolved in methanol, namely, cannabidivarin
(CBDV, 1 mg/mL), cannabidiolic acid (CBDA, 1 mg/mL), cannabigerol
(CBG, 1 mg/mL), cannabidiol (CBD, 1 mg/mL), cannabinol (CBN, 1 mg/mL),
(−)-Δ⁹-tetrahydrocannabinol [(−)-Δ⁹-THC, 1 mg/mL], (−)-Δ⁸-tetrahydrocannabinol
[(−)-Δ⁸-THC, 1 mg/mL], cannabichromene (CBC,
1 mg/mL), and (−)-Δ⁹-tetrahydrocannabinolic
acid ((−)-Δ⁹-THCA, 1 mg/mL) with a purity
of ≥99%, were purchased from Merck Life Science (Milan, Italy).
Preparative TLC plates UV 254 nm (surface 20 × 20 cm, thickness
500 μm), used for the purification of CBC, were purchased from
Merck (Darmstadt, Germany).

Gradient grade water, acetonitrile, chloroform, methanol, and formic acid were purchased from Merck Life Science (Milano, Italy). Cannabinoid reference standards dissolved in methanol, namely, cannabidivarin (CBDV, 1 mg/mL), cannabigerol (CBG, 1 mg/mL), cannabidiol (CBD, 1 mg/mL), cannabidiolic acid (CBDA, 1 mg/mL), cannabinol (CBN, 1 mg/mL), (–)-Δ9-tetrahydrocannabinol ((–)-Δ9-THC, 1 mg/mL), Δ9-tetrahydrocannabinolic acid ((–)-Δ9-THCA, 1 mg/mL), (–)-Δ8- tetrahydrocannabinol ((–)-Δ8-THC, 1 mg/mL), and cannabichromene (CBC, 1 mg/mL) with purity ≥ 99%, were purchased from Merck Life Science (Milano, Italy). Deuterated water (D₂O) 99.97 atom% of deuterium and 3-(trimethylsilyl)-propionic-2,2,3,3-d₄ acid sodium salt (TSP) were purchased from Euriso-Top (Saclay, France). Magnesium oxide (MgO), potassium phosphate monobasic (KH₂PO₄), and potassium phosphate dibasic (K₂HPO₄) 2,2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu reagent, gallic acid (GA), and sodium carbonate (Na₂CO₃) were purchased from Merck Life Science (Milano, Italy).

LC–MS grade chemicals (methanol, ethyl acetate, isopropanol, ammonium formate, formic acid, n-hexane, n-heptane, n-pentane) with purities in the range of 98.5–99.8% were purchased from Merck. Deionized water (18 mΩ) was obtained from an internal Milli-Q system (Millipore). P.A. 96% ethanol was purchased from Lach-Ner. Analytical standards of 17 phytocannabinoids (cannabidiol (CBD), cannabidiolic acid (CBDA), delta-8-tetrahydrocannabinol (∆⁸-THC), delta-9-tetrahydrocannabinol (∆⁹-THC), delta-9-tetrahydrocannabinolic acid (∆⁹-THCA-A), cannabigerol (CBG), cannabigerolic acid (CBGA), cannabicyclol (CBL), cannabicyclolic acid (CBLA), cannabidivarin (CBDV), cannabidivarinic acid (CBDVA), tetrahydrocannabivarin (THCV), tetrahydrocannabivarinic acid (THCVA), cannabinol (CBN), cannabinolic acid (CBNA), cannabichromene (CBC), and cannabichromenic acid (CBCA)) in purity ranges from 95 to 100% were purchased from Merck.