*2.2. Chemical Analysis of the EO*

In the chemical analysis of the EO of *J. rugosa*, all components identified were sesquiterpenes corresponding to a total of 56 and 53 compounds, respectively, with DB-5ms and HP-INNOWax columns (see Section 4.4). Most of the constituents (52) were identified by comparing the electron impact mass spectrum (EIMS) and the linear retention index (LRI) with literature, whereas four remained unidentified. According to their molecular weight, the unknown components are consistent with one sesquiterpene (204 amu) and three oxygenated sesquiterpenoids (220, 262 and 280 amu). The significant difference between calculated and reference LRIs is within the experimental error.

Concerning the quantitative analysis (see Section 4.5), 50 compounds were quantified on at least one column, with a detection threshold of 0.1%, whereas six compounds (β-cubebene, α-chamipinene, δ-amorphene, *allo*-aromadendrene epoxide, *cis*-thujopsenal, and 8-α-acetoxyelemol) appeared as traces (<0.1%) in both columns. Quantified components corresponded to 98.3% and 99.6% of the EO total mass, on the non-polar and polar column, respectively; the sesquiterpene hydrocarbons, corresponding to 75.8% and 80.8% and oxygenated sesquiterpenes, corresponding to 22.3–18.8%, respectively. The major components, with an average amount ≥3% over the two columns, were γ-curcumene (47.1%, 49.7%), β-sesquiphellandrene (17.0%, 17.9%), *ar*-curcumene (3.4%, 4.2%) and two undetermined oxygenated sesquiterpenes with molecular weight 220 (6.7%, 7.2%) and 262 (4.7%, 3.3%). A standard deviation of less than 5% was obtained between the percentages of each analyte with both columns. The GC-MS chromatograms on both columns are reported in Figures 1 and 2. Table 1 shows the identified components together with their relative percent abundance, calculated vs. *n*-nonane as the internal standard.

**Figure 1.** GC-MS chromatogram of *J. rugosa* EO on DB-5ms column.

**Figure 2.** GC-MS chromatogram of *J. rugosa* EO on HP-INNOWax column.




**Table 1.** *Cont*.

<sup>1</sup> Calculated linear retention index (LRI) according to van den Dool and Kratz [48]; <sup>2</sup> Trace for % < 0.1.
