α pinene

The following terpenoid standards were purchased from Supelco: α-pinene, camphene, β-pinene, myrcene, 3-carene, α-terpinene, p-cymene, limonene, γ-terpinene, fenchone, terpinolene, linalool, camphor, isoborneol, borneol, menthol, α-terpineol, β-citronellol, neryl acetate, geranyl acetate, α-cedrene, β-caryophyllene, α-humulene, cis-nerolidol, geranyl isobutyrate, caryophyllene oxide, β-eudesmol, α-bisabolol, and phytol. Cannabinoid standards were purchased from Sigma Aldrich (1 mg/mL): cannabidiolic acid (CBD-A), cannabigerolic acid (CBG-A), cannabigerol (CBG), cannabidiol (CBD), cannabinol (CBN), Δ-9-tetrahydrocannabinol (Δ-9-THC), Δ-8-tetrahydrocannabinol (Δ-8-THC), cannabichromene (CBC), Δ-9-tetrahydrocannabinolic acid (Δ-9-THC-A), and cannabichromenic acid (CBC-A). Acid standards were dissolved in acetonitrile, and nonacid standards were dissolved in methanol. Hexane, ammonium format, and acetonitrile were purchased from Sigma Aldrich, methanol was purchased from J. T. Baker and formic acid was purchased from Scharlau. Chemical structures of essential oils and cannabinoids are presented in Supplementary Materials [37 ,38 ,39 ].

Lavender oil (Ph Eur 9.0), peppermint oil (Ph Eur 9.0), Arabic gum from acacia tree (Ph Eur 9.0), maltodextrin (from maize starch, dextrose equivalent 8.0–15.0), sorbitan monooleate (Span^® 80), polyoxyethylene sorbitan monooleate (Tween^® 80), and n-hexane were purchased from Sigma-Aldrich, Germany. Analytical standards for gas chromatography analysis (α-pinene, β-pinene, 3-octanon, limonene, linalool, camphor, menthone, menthol, menthyl acetate, caryophyllene) were supplied from Supelco Analytical, Germany.

Pure reference standards of (E)-5-methyl-2-hepten-4-one (filbertone), ethyl-2-methylbutyrate, α-pinene, linalool, and limonene used for identity confirmation were supplied by Merck (Milan, Italy). Working solutions were prepared in cyclohexane at a final concentration of 100 mg/L.
n-Alkanes (n-C9 to n-C25), adopted for linear retention indices (I^T) calibration, were from Merck (Milan, Italy): the test mixture was prepared in cyclohexane at a final concentration of 100 mg/L.

The M. myristica, X. aethiopica, and A. citratum EOs were prepared by a 1:100 dilution with hexane and analyzed with an Agilent 6890N–5973N GC–MS system operating in the EI mode at 70 eV, using a HP-5MS (5% phenylmethylpolysiloxane, length 30 m, internal diameter 0.25 mm, film thickness 0.1 µm; J & W Scientific, Folsom, CA, USA) capillary column. The total duration of the run was around 66 min with the following temperature program: 60 °C for 5 min, afterward up to 220 °C at 4 °C min⁻¹, then up to 280 °C at 11 °C min⁻¹ and maintained for 15 min. The carrier gas used in this analysis was helium at a flow rate of 1 mL min⁻¹. The injection volume was 2 μL and the split ratio 1:50. The range of acquisition was 29–400 m z⁻¹. The combination of linear retention indices (RIs) and mass spectra (MS) with those appearing in libraries such as Adams (2007), FFNSC2 (2012), and NIST17 (2017) was the method used for the peak identification unless no analytical standard (purchased from Merck, Milan, Italy) was available. The analytical standards of the major EO components, namely geraniol, sabinene, α-pinene, p-cymene, α-phellandrene, and β-pinene, were purchased from Merck (Milan, Italy). Relative peak area percentage for each identified compound was extracted from the total area in the chromatogram without using correction factors.

SupraSolv dichloromethane was used for the gas chromatography, anhydrous Na₂SO₄ granulated for organic trace analysis, and the pure compounds (Ph. Eur.)—α-pinene, (+)-limonene, phellandrene, eucalyptol, borneol, camphor and nerolidol—were purchased from Merck, Darmstadt, Germany. The n-alkanes C₈–C₂₄ used for the determination of the Kovats retention indices were from Fluka, Switzerland.

A mixture of n-alkanes (C6–C10) dissolved in pentane was purchased from Fluka (Buchs, Switzerland) and α-pinene (≥95%) from Merck. All other reference compounds were supplied by Sigma-Aldrich (Munich, Germany): (E)-2-hexen-1-ol (≥ 95%), (E)-2-octenal (≥94%), (E)-2-nonenal (≥93%), hexyl acetate (99%), 1-decyne (98%), (Z)-3-hexenyl acetate (≥98%), (E)-2-decenal (analytical standard), 3-methyl-1-butanol acetate (isoamyl acetate) (≥97%), benzaldehyde (≥99%), nonanal (97%), (E)-2-hexenal (98%), (E)-2-octen-1-ol (97%), decanal (≥98%), 2,4-octadienal (96%), (E,E)-2,4-decadienal (analytical standard), (R)-(+)-limonene (97%), (E,E)-2,4-hexadienal (≥95%). Dichloromethane (anhydrous, ≥99.8%) and pentane (anhydrous, ≥99%) used as diluents were also from Sigma-Aldrich.
Samples of the reference compounds were prepared by dilution of the individual compounds in Dichloromethane, except for a mixture of alkanes which were diluted in pentane. The concentration of stock solutions of each compound was 0.1 mg mL⁻¹ but the final dilution of each standard was individually modified to obtain good reproducibility of retention times.

The antibiotics (AB) used in this study were amoxicillin, ampicillin, doxycycline, lincomycin, neomycin, penicillin G, and colistin (all obtained from Alpha Aesar, Thermo Fisher GmbH, Kandel, Germany); AB stock solutions were prepared in BHI. Organic acids (OA) and nature-identical compounds (NIC) utilized in this study were citric acid, sorbic acid, benzoic acid, butyric acid, hexanoic acid, formic acid, fumaric acid, lactic acid, malic acid, and propionic acid (stocks prepared in BHI); and octanoic acid, decanoic acid, dodecanoic acid, thymol, carvacrol, eugenol, vanillin, α-pinene, eucalyptol, limonene, linalool, and menthol (stocks prepared in BHI supplemented with ethanol at a final concentration ≤ 3.5% to increase solubility); all OA and NIC were obtained from Merck KGaA, Darmstadt, Germany. Each solution was buffered to ensure a final pH of 6.5, filter-sterilized and diluted in sterile BHI to reach the final concentration tested.