Vitexin 2 o rhamnoside

The extract was fractionated by liquid-liquid partition in order to obtain the dichloromethane (CH₂Cl₂), ethyl acetate (AcOEt), n-butanol (BuOH), and residual aqueous fractions, respectively. Then, the extract and fractions were analyzed by Thin Layer Chromatography (TLC) using aluminum precoated sheets with silica gel F₂₅₄ (Merck®, Darmstadt, Germany) as adsorbent. Two different mobile phases were used: ethyl acetate : formic acid : water (8 : 1 : 1 v/v/v) and toluene : ethyl acetate : formic acid (5 : 5 : 0.5 v/v/v). The chromatograms were analyzed under 365 nm UV light and then sprayed with specific chromogenic agents according to the class of compounds investigated (Dragendorff reagent, natural reagent A, ferric chloride, and sulfuric vanillin and heating). The retention factor, behavior, and color of the spots were compared with the chromatographic profiles of the reference substances. According to the results, standard samples of the flavonoids apigenin (≥99%), luteolin (≥98%), luteolin-7-O-glucoside (≥98%), orientin (≥97%), isoorientin (≥98%), vitexin (≥95%), isovitexin (≥98%), and vitexin-2-O-rhamnoside (≥98%) (Sigma-Aldrich) were compared with the extract and fractions. When necessary to confirm the presence of any substance in extract and/or fractions, they were analyzed by co-TLC.

The flavonoids aglycones luteolin, chrysoeriol and kaempferol were obtained from Extrasynthèse S.A. (Lyon, France). Vitexin-2-O-rhamnoside, apigenin-7-O-glucuronide, apigenin, quercetin, cannabigerolic acid (CBGA), tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) were purchased from Sigma-Aldrich Chemie GmbH (Buchs, Switzerland) and luteolin-7-O-glucuronide from HWI-group (Rülzheim, Germany). (+)-alpha-Pinene, (−)-beta-Pinene, beta-Myrcene, Ocimene, L-Linalool, (E)-beta-Caryophyllene, alpha-Humulene, (−)-alpha-Bisabolol, S(−)-Limonene, alpha-Phellandrene, 1.8-Cineol, Terpinolene and gamma-Terpinene were purchased from Sigma-Aldrich Chemie GmbH (Buchs, Switzerland).
Acetonitrile (LC-MS grade) was supplied by VWR International GmbH (Dietikon, Switzerland). Water (LC-MS grade) and methanol (HPLC grade) were supplied by Carl Roth AG (Arlesheim, Switzerland). Trifluoroacetic acid (TFA) and dimethysulfoxide (DMSO) were supplied by Sigma-Aldrich Chemie GmbH (Buchs, Switzerland).

The flavonoids apigenin (≥99%), luteolin (≥98%), luteolin-7-O-glucoside (≥98%), orientin (≥97%), isoorientin (≥98%), vitexin (≥95%), isovitexin (≥98%), and vitexin-2-O-rhamnoside (≥98%) (Sigma-Aldrich®) were purchased from Sigma-Aldrich (St. Louis, MO, USA). All other reagents and solvents used were of analytical grade. The water used was purified by reverse osmosis.