Germacrene d

The standard substances α-pinene (98%), sabinene (95%), p-cymene (99%), limonene (97%), linalool (97%), γ-terpinene (96%), (E)-β-caryophyllene (98.5%), germacrene D (90%), α-humulene (96%), caryophyllene oxide (95%) (98%), p-hydroxybenzoic acid (99%), caffeic acid (98%), o-hydroxybenzoic acid (99%), rosmarinic acid (97%), rutin (94%), AAPH (97%), and fluorescein (99%) were purchased from Sigma Aldrich (St. Louise, MO, USA), and luteolin-7-O-glucoside (98%), kaempferol-3-O-rutinoside (98%), and salvigenin (98%) were purchased from ChemFaces (Wuhan, China); vitexin (≥95%) was purchased from PhytoLab GmbH (Vestenbergsgreuth, Bavaria, Germany). Solvents and other reagents used in the extraction process, GC/FID grade dichloromethane, ammonium formate (99%), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), formic acid HPLC grade, potassium persulfate (99%), and absolute ethanol (96%) were purchased from Merck (Darmstadt, Germany); commercial ethanol (96%) was acquired from SUQUIN (Bucaramanga, Santander, Colombia).

The GC/MS analyses were performed on a Agilent Technologies 7890A Gas Chromatograph, equipped with a HP 5MS 30 m × 0.25 mm × 0.25 μm film thickness capillary column, connected with an Agilent 5957C, VL MS Detector with Triple-Axis Detector system operating in EI mode, and He as the carrier gas (1 mL/min). The initial column temperature was 60°C and heated gradually to 280°C with a 3°C/min rate. The identification of the compounds was based on comparison of their Retention Indices (RI) obtained, using various n-alkanes (C₉–C₂₄) and their EI-mass spectra were compared with the NIST/NBS, Wiley libraries spectra, and literature [19 , 20 ]. Additionally, the identity of the indicated phytochemicals was confirmed by comparison with available authentic samples. All authentic samples utilized for the identification of EOs compounds were obtained from Sigma-Aldrich, except for germacrene D and α-thujene, which had been isolated in the context of previous studies.

All the chemicals and reagents involved in the extraction processes, total polyphenolic content, antioxidant activity experiments and the chemical standards (1-hexanol, 2-Thujene, 3-octanone, 5-Amino-1-ethylprazole, Allylbenzene, Camphene, Caryophyllene oxide, Decanoic acid, Docosane, Germacrene D, Hexadecane, HexaDecanoic acid, Lavandulol, Limonene, Linalool, Linalool acetate, Nerol, Nerolidol, Ninanal, TetraDecanoic acid, Tricosane, α-Copaene, α-Humulene, α-Ter-pinene, β-Bourbonene, β-Caryophyllene, β-Copaene, β-Cubenene, β-Farnesene, β-Gurjunene, β-Myrcene, β-Pinene) used in the identification of phenolic and aromatic compounds from the extracts were acquired from Sigma Aldrich Company (St. Louis, MO, USA).