# Comparative Study of the Chemical Composition of Root, Stem and Leaf Essential Oils from Synedrella nodiflora (L.) Gaertn

Didjour Albert Kambiré, Kayatou Touré, Thierry Acafou Yapi, Mathieu Paoli, Ange Bighelli, Jean Brice Boti, Félix Tomi

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Didjour Albert Kambiré, Kayatou Touré, Thierry Acafou Yapi, Mathieu Paoli, Ange Bighelli, et al. Comparative Study of the Chemical Composition of Root, Stem and Leaf Essential Oils from Synedrella nodiflora (L.) Gaertn. Compounds, 2024, 4 (3), pp.521 - 533. 10.3390/compounds4030031. hal-05034510

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# Comparative Study of the Chemical Composition of Root, Stem and Leaf Essential Oils from *Synedrella nodiflora* (L.) Gaertn

Didjour Albert Kambiré<fnref n="1" />, Kayatou Touré<fnref n="2" />, Thierry Acafou Yapi<fnref n="2" />, Mathieu Paoli<fnref n="3" />, Ange Bighelli<fnref n="3" />, Jean Brice Boti<fnref n="2" /> and Félix Tomi<fnref n="3" />,*

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**Citation:** Kambiré, D.A.; Touré, K.; Yapi, T.A.; Paoli, M.; Bighelli, A.; Boti, J.B.; Tomi, F. Comparative Study of the Chemical Composition of Root, Stem and Leaf Essential Oils from *Synedrella nodiflora* (L.) Gaertn.
*Compounds* **2024**, *4*, 521–533. https://doi.org/10.3390/compounds4030031

Academic Editor: Juan C. Mejuto

Received: 17 June 2024

Revised: 3 August 2024

Accepted: 13 August 2024

Published: 20 August 2024

<figure><img src="image_3.png" /></figure>

**Copyright:** © 2024 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

**Abstract:** This study aims at investigating the chemical composition of root, stem and leaf essential oils from Ivorian *Synedrella nodiflora*, with the root oil being described for the first time. Sixty, fifty-one and forty-nine constituents were, respectively identified in the root, stem and leaf oils using a combination of GC(RI), GC-MS and ¹³C-NMR analyses. They accounted for 95.6–97.3%, 92.6–97.6% and 93.3–98.8% of the total composition, respectively. The main components of the root oil samples were γ-curcumene, (E)-β-caryophyllene, α-curcumene and curcuphenyl acetate. Three stem oil samples (S1, S2a, S3) were dominated by myrcene and limonene, while the most abundant components of sample S2b were thymol, germacrene D and β-elemene. (E)-β-caryophyllene and germacrene D were the major compounds of the leaf oil. Hierarchical cluster and principal component statistical analyses were performed and confirmed that the location does not influence the chemical composition. Group I consisted of the seven leaf oil samples, group II consisted of four stem oil samples and group III consisted of three root oil samples. The root oil composition differed considerably from the stem and leaf oil composition due to the presence of curcumene derivatives as major constituents. The leaf oil showed significant amounts of (E)-β-caryophyllene and germacrene D, while the stem oil stood out for its high myrcene, limonene and thymol contents.

**Keywords:** *Synedrella nodiflora*; essential oil; chemical composition; Côte d'Ivoire

## 1. Introduction

*Synedrella nodiflora* (L.) Gaertn (synonyms *Ucacou nodiflorum* (L.) Hitchc. and *Verbesina nodiflora* L.) is a herbaceous, erect, branched, pubescent annual plant belonging to the genus *Synedrella*, which contains only one species from the Asteraceae family. It grows in ruderal and sometimes humid places and can reach 60 cm to 1 m in height [1]. The leaves have veins and are hairy, glabrous, elliptical or ovate, pinnate, an acuminated apex, are obtuse at the base end and toothed. Native to tropical America, this plant is widely distributed in the humid regions of West Africa [2,3].

The leaves of *S. nodiflora* are commonly eaten by cattle and humans. *S. nodiflora* is used in traditional medicine in various therapeutic indications. The sap from leaves is used to treat earaches, headaches and abdominal pain. Leaf infusion is taken orally as a laxative, and root decoction is used against cough. The whole plant is further used against arthritis, rheumatism, oedema, hematoma, leprosy, mycosis, gonorrhea, hemorrhoids, diarrhea, insect pests and to stop bleeding [1–7]. In tropical regions of the world (Africa, Asia, Caribbean and Latin America) the plant is used as an anti-inflammatory, emmenagogue, diuretic, contraceptive and against varicose ulcers, wounds, leprosy, heart diseases and

<footnote n="1">¹ UPR de Chimie Organique, Département de Mathématiques, Physique et Chimie, UFR des Sciences Biologiques, Université Eleforo Gon Coulibaly, Korhogo BP 1328, Côte d'Ivoire; dakambire@gmail.com</footnote>

<footnote n="2">² Laboratoire de Constitution et Réaction de la Matière, UFR-SSMT, Université Félix Houphouët-Boigny, Abidjan BP V34, Côte d'Ivoire; kaditoure524@gmail.com (K.T.); acafouth@yahoo.fr (T.A.Y.); jeanbriceboti@hotmail.fr (J.B.B.)</footnote>

<footnote n="3">³ Laboratoire Sciences Pour l'Environnement, Université de Corse—CNRS, UMR 6134 SPE, Route des Sanguinaires, 20000 Ajaccio, France; paoli_m@univ-corse.fr (M.P.); bighelli_a@univ-corse.fr (A.B.)</footnote>

<footnote>* Correspondence: tomi_f@univ-corse.fr</footnote>
colds. The aqueous extract is drunk to treat epilepsy, hiccups and as an anti-abortion measure [8].

Investigations into solvent extracts, essential oil composition and the biological activity of *S. nodiflora* were previously reported. Phytochemical screenings revealed the presence of alkaloids, steroids, triterpenoids, coumarins, tannins and other phenolic compounds [3–11]. Antioxidant, anti-inflammatory, insecticidal, antimicrobial and antibacterial activities were also evidenced for some solvent extracts [1,4,6,7,9,10]. The chemical composition of the plant essential oil from India is dominated by farnesene, β-caryophyllene, δ-cadinene and germacrene D [12]. The essential oil of leaves from islands in Fiji showed high amounts of β-caryophyllene followed by β-farnesene, germacrene D and β-cubebene [13], while limonene, α-santalene, *n*-tetradecane and *n*-hexadecane are the main compounds of the stem essential oil from Nigeria [14]. In Côte d'Ivoire, the composition of a single sample of leaf oil was previously described, with a predominance of β-caryophyllene, germacrene D, caryophyllene oxide and β-elemene [15].

This study is part of our works on the chemical characterization of essential oils from Côte d'Ivoire [16–20]. We report the determination and the comparison of the chemical composition of the essential oil of three organs (root, stem and leaf) of *S. nodiflora* in three locations characterized by diverse pedoclimatic conditions, littoral humid forests and wooded savannah. The essential oil composition of the root is being reported here for the first time, to our knowledge.

## 2. Materials and Methods

### 2.1. Plant Material and Essential Oil Isolation

The fresh roots, stems and leaves of *S. nodiflora* were collected from the edge of the following two forests: Adiopodoumé Forest, Region of Lagunes, southern Côte d'Ivoire, geographical coordinates 5°19'57.7" N and 4°08'02.0" W (Location 1); Yapo-Abbé Forest, Region of Agneby-Tiassa, southern Côte d'Ivoire, geographical coordinates 5°40'43.1" N and 4°05'56.0" W (Location 2); and nearby Korhogo, Region of Poro, northern Côte d'Ivoire, geographical coordinates 9°25'20.7" N and 5°38'18.3" W (Location 3). The harvest took place during the dry season (January and February 2021), and plant material was authenticated by botanists from the Centre Suisse de Recherches Scientifiques (CSRS) and the Centre National de Floristique (CNF, Abidjan, Côte d'Ivoire) in accordance with voucher specimens available at the CNF. The fresh leaves, stems and root samples were hydrodistilled for 3 h each using a Clevenger-type apparatus. Essential oil yields were calculated from fresh plant material (*w/w*) and are reported in Table 1.

<table><caption>**Table 1.** Plant material and essential oil extraction data.</caption><thead><tr><th rowspan="2">Sample</th><th rowspan="2">Harvest Site<br>Elevation (m)</th><th rowspan="2">Organ</th><th colspan="2">Weight (g)</th><th rowspan="2">Yield (%)</th></tr><tr><th>Plant Material</th><th>Essential Oil</th></tr></thead><tbody><tr><td>R1</td><td rowspan="4">Adiopodoumé Forest:<br>littoral humid forest 32</td><td>Roots</td><td>109.7</td><td>0.0443</td><td>0.040</td></tr><tr><td>S1</td><td>Stems</td><td>462.4</td><td>0.0869</td><td>0.019</td></tr><tr><td>L1a</td><td rowspan="2">Leaves</td><td>628.1</td><td>0.0692</td><td>0.011</td></tr><tr><td>L1b</td><td>612.7</td><td>0.0857</td><td>0.014</td></tr><tr><td>R2</td><td rowspan="6">Yapo-Abbé Forest:<br>littoral humid forest 80</td><td>Roots</td><td>459.3</td><td>0.2297</td><td>0.050</td></tr><tr><td>S2a</td><td rowspan="4">Stems</td><td>911.4</td><td>0.1458</td><td>0.016</td></tr><tr><td>S2b</td><td>898.0</td><td>0.2104</td><td>0.023</td></tr><tr><td>L2a</td><td>840.8</td><td>0.3335</td><td>0.040</td></tr><tr><td>L2b</td><td>835.9</td><td>0.1976</td><td>0.024</td></tr><tr><td>L2c</td><td>Leaves</td><td>877.2</td><td>0.2543</td><td>0.029</td></tr><tr><td>R3</td><td rowspan="4">Korhogo:<br>wooded savannah 376</td><td>Roots</td><td>428.7</td><td>0.1839</td><td>0.043</td></tr><tr><td>S3</td><td rowspan="2">Stems</td><td>926.1</td><td>0.2039</td><td>0.022</td></tr><tr><td>L3a</td><td>812.4</td><td>0.3005</td><td>0.037</td></tr><tr><td>L3b</td><td>Leaves</td><td>817.0</td><td>0.2861</td><td>0.035</td></tr></tbody></table>
## 2.2. Gas Chromatography

Analyses were performed on a Clarus 500 PerkinElmer Chromatograph (PerkinElmer, Courtaboeuf, France) equipped with a flame ionization detector (FID) and two fused-silica capillary columns (50 m × 0.22 mm, film thickness 0.25 µm), BP-1 (polydimethylsiloxane) and BP-20 (polyethylene glycol). The oven temperature was programmed from 60 °C to 220 °C at 2 °C/min and then held isothermal at 220 °C for 20 min; the injector temperature was 250 °C; the detector temperature was 250 °C; the carrier gas was hydrogen (0.8 mL/min); the split was 1/60; and the injected volume was 0.5 µL. Retention indices (RI) were determined relative to the retention times of a series of n-alkanes (C8–C29) with linear interpolation ("Target Compounds" software 2013 from PerkinElmer). The quantification of the volatile compounds was obtained using a relative response factor (RRF) and calculated according to the International Organization of the Flavor Industry (IOFI). The relative proportion of each compound (expressed in g/100 g) was calculated using the weight of the essential oil and reference (methyl octanoate), the peak area and relative response factors [21].

## 2.3. Gas Chromatography–Mass Spectrometry in Electron Impact Mode

The essential oil samples were analyzed with a Clarus SQ8S PerkinElmer TurboMass detector (quadrupole) directly coupled with a Clarus 580 PerkinElmer Autosystem XL (PerkinElmer, Courtaboeuf, France) equipped with a BP-1 (polydimethylsiloxane) fused-silica capillary column (60 m × 0.22 mm i.d., film thickness 0.25 µm). The oven temperature was programmed from 60 to 230 °C at 2°/min and then held isothermal for 45 min. Additionally, the injector temperature was 250 °C; the ion-source temperature was 250 °C; the carrier gas was He (1 mL/min); the split ratio was 1:80; the injection volume was 0.2 µL; and the ionization energy was 70 eV. The electron ionization (EI) mass spectra were acquired over the mass range 35–350 Da.

## 2.4. Nuclear Magnetic Resonance

The ¹³C-NMR spectra of 14 samples (root, stem, leaf) were recorded on a Bruker AVANCE 400 Fourier transform spectrometer (Bruker, Wissembourg, France) operating at 100.623 MHz for ¹³C, equipped with a 5 mm probe, in CDCl₃, with all shifts referring to the internal TMS. The following parameters were used: pulse width = 4 µs (flip angle 45°); relaxation delay D1 = 0.1 s, acquisition time = 2.7 s for 128 K data table with a spectral width of 25,000 Hz (250 ppm); CPD mode decoupling; digital resolution = 0.183 Hz/pt. The number of accumulated scans was 3000 for each sample (40 mg, when available, in 0.5 mL of CDCl₃).

A laboratory-made software compares the chemical shift of every carbon in the experimental spectrum with the spectra of pure compounds listed in our in-house data library [22,23]. Each compound was identified taking into account the following:

- The number of observed carbons with respect to the number of expected signals;

- The number of overlapped signals of carbons which possess fortuitously the same chemical shift;

- The difference of chemical shift of each signal in the mixture spectrum and in the reference.

These three parameters are directly available from the computer program. A compound was considered as identified when at least 50% of its signals belonging solely to that molecule and 70% of all its signals was observed.

## 2.5. Identification of Individual Components

Identification of the individual components was achieved as follows: (i) by comparison of their GC retention indices (RI) on apolar and polar columns with those of reference compounds [24–26]; (ii) through computer matching against digital mass spectral libraries [24,27,28]; (iii) through comparison of the signals in the ¹³C-NMR spectra of the samples with those of reference spectra compiled in the laboratory spectral library with
the help of laboratory-made software [22,23]. This method allowed for the identification of individual components of the essential oil at contents as low as 0.4–0.5%.

## 2.6. Statistical Analysis

The chemical compositions of the 14 essential oil samples from *S. nodiflora* were submitted to hierarchical cluster analysis (HCA) and principal component analysis (PCA) using XLSTAT 2016 software (Addinsoft, Paris, France) [29]. Only constituents in a concentration of 1.0% and higher were used as variables for the PCA analysis. The XLSTATS-3DPlot module was used to afford 3D PCA using the principal factors F1, F2 and F3. The aptitude of the complete correlation matrix was checked by the Kaiser–Meyer–Olkin criterion. The HCA and dendrogram were made with dissimilarity matrices calculated through the Euclidean distance, and the average link was the aggregation method systematically chosen.

# 3. Results and Discussion

The chemical compositions of the essential oils from three organs of *S. nodiflora* growing wild in Côte d'Ivoire were determined. Essential oils were isolated by hydrodistillation of fresh plant material collected from the edge of the Yapo-Abbé and the Adiopodoumé forests, both in Southern Côte d'Ivoire and nearby Korhogo (north of the country). The oil extraction yields calculated on a weight (w/w) basis varied poorly at 0.040–0.050% (root oil samples), 0.016–0.023% (stem oil samples) and 0.011–0.040% (leaf oil samples). A combination of GC(RI)(non-polar and polar columns), GC-MS (non-polar column) and ¹³C-NMR, following a computerized method developed at the University of Corsica [22,23], was used to analyze the oil samples.

## 3.1. Chemical Composition of the Root's Essential Oil

The root essential oil from *S. nodiflora* is characterized for the first time. The analysis of three oil samples led to the identification of 60 compounds, accounting for 95.6–97.3% of the whole chemical composition. They primarily consist of hydrocarbon sesquiterpenes (59.4–72.3%) followed by oxygenated sesquiterpenes (13.3–18.7%). Hydrocarbon monoterpenes and oxygenated monoterpenes accounted for 2.7–11.5% and 3.3–10.2%, respectively. Rich in curcumene derivatives, this essential oil is dominated by γ-curcumene (22.2–24.8%), (E)-β-caryophyllene (11.7–22.2%), α-curcumene (11.6–12.4%) and curcuphenyl acetate (5.6–10.7%). The majority of compounds are followed by xanthorrhizyl acetate (1.3–6.2%) and neryl isovalerate (1.2–6.2%). Other compounds are also present in significant proportions, such as β-pinene (1.0–4.6%), α-pinene (1.0–4.4%), cyclosativene (2.1–3.6%) and cyperene (1.0–3.5%) (Table 2). The harvest sites have a negligible influence on the chemical composition of the root essential oil from *S. nodiflora* due to the geographic areas (littoral humid forests and wooded savannah) of the three harvest sites being distant (around 550 km).

<table><caption>**Table 2.** Chemical composition of root essential oil from *Synedrella nodiflora*.</caption><thead><tr><th>N°</th><th>Compounds</th><th>RIaL</th><th>RIa</th><th>RIp</th><th>RRF</th><th>A (%)<br>R1</th><th>Y-A (%)<br>R2</th><th>K (%)<br>R3</th><th>Identification</th></tr></thead><tbody><tr><td>1</td><td>α-Pinene</td><td>934</td><td>931</td><td>1020</td><td>0.765</td><td>4.4</td><td>1.7</td><td>1.0</td><td>RI, MS, ¹³C-NMR</td></tr><tr><td>2</td><td>Camphene</td><td>947</td><td>945</td><td>1071</td><td>0.765</td><td>0.1</td><td>0.2</td><td>tr</td><td>RI, MS</td></tr><tr><td>3</td><td>Sabinene</td><td>968</td><td>966</td><td>1127</td><td>0.765</td><td>0.1</td><td>0.2</td><td>0.1</td><td>RI, MS</td></tr><tr><td>4</td><td>β-Pinene</td><td>973</td><td>971</td><td>1116</td><td>0.765</td><td>2.2</td><td>4.6</td><td>1.0</td><td>RI, MS, ¹³C-NMR</td></tr><tr><td>5</td><td>Myrcene</td><td>983</td><td>981</td><td>1166</td><td>0.765</td><td>0.4</td><td>2.4</td><td>0.3</td><td>RI, MS, ¹³C-NMR</td></tr><tr><td>6</td><td>α-Phellandrene</td><td>999</td><td>998</td><td>1170</td><td>0.765</td><td>0.1</td><td>0.1</td><td>-</td><td>RI, MS</td></tr><tr><td>7</td><td>p-Cymene</td><td>1015</td><td>1012</td><td>1276</td><td>0.698</td><td>0.1</td><td>tr</td><td>tr</td><td>RI, MS</td></tr><tr><td>8</td><td>β-Phellandrene *</td><td>1021</td><td>1022</td><td>1215</td><td>0.765</td><td>0.2</td><td>0.3</td><td>0.1</td><td>RI, MS</td></tr><tr><td>9</td><td>Limonene *</td><td>1024</td><td>1022</td><td>1206</td><td>0.765</td><td>0.5</td><td>1.7</td><td>0.2</td><td>RI, MS, ¹³C-NMR</td></tr><tr><td>10</td><td>(E)-β-Ocimene</td><td>1038</td><td>1035</td><td>1254</td><td>0.765</td><td>-</td><td>0.3</td><td>-</td><td>RI, MS</td></tr></tbody></table>
<table><caption>**Table 2. Cont.**</caption><thead><tr><th>N°</th><th>Compounds</th><th>RIaL</th><th>RIa</th><th>RIp</th><th>RRF</th><th>A (%) R1</th><th>Y-A (%) R2</th><th>K (%) R3</th><th>Identification</th></tr></thead><tbody><tr><td>11</td><td>α-Terpineol</td><td>1175</td><td>1174</td><td>1697</td><td>0.809</td><td>0.1</td><td>0.1</td><td>tr</td><td>RI, MS</td></tr><tr><td>12</td><td>Neral</td><td>1220</td><td>1215</td><td>1682</td><td>0.817</td><td>-</td><td>-</td><td>0.2</td><td>RI, MS</td></tr><tr><td>13</td><td>Geraniol</td><td>1238</td><td>1236</td><td>1848</td><td>0.809</td><td>0.1</td><td>tr</td><td>0.2</td><td>RI, MS</td></tr><tr><td>14</td><td>Geranial</td><td>1247</td><td>1244</td><td>1732</td><td>0.817</td><td>-</td><td>-</td><td>0.3</td><td>RI, MS</td></tr><tr><td>15</td><td>Thymol</td><td>1271</td><td>1268</td><td>2188</td><td>0.755</td><td>0.7</td><td>0.1</td><td>0.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>16</td><td>Bornyl acetate</td><td>1270</td><td>1270</td><td>1582</td><td>0.849</td><td>0.8</td><td>0.5</td><td>0.3</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>17</td><td>α-Cubebene</td><td>1352</td><td>1350</td><td>1458</td><td>0.751</td><td>tr</td><td>-</td><td>0.2</td><td>RI, MS</td></tr><tr><td>18</td><td>Longicyclene</td><td>1371</td><td>1366</td><td>1489</td><td>0.751</td><td>0.2</td><td>0.3</td><td>0.2</td><td>RI, MS</td></tr><tr><td>19</td><td>Cyclosativene</td><td>1368</td><td>1369</td><td>1483</td><td>0.751</td><td>2.1</td><td>3.6</td><td>3.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>20</td><td>α-Copaene</td><td>1375</td><td>1375</td><td>1493</td><td>0.751</td><td>0.4</td><td>0.7</td><td>0.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>21</td><td>β-Elemene</td><td>1388</td><td>1387</td><td>1591</td><td>0.751</td><td>0.8</td><td>1.9</td><td>0.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>22</td><td>Cyperene</td><td>1398</td><td>1399</td><td>1528</td><td>0.751</td><td>3.5</td><td>3.3</td><td>1.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>23</td><td>α-Gurjunene</td><td>1405</td><td>1409</td><td>1531</td><td>0.751</td><td>0.4</td><td>0.6</td><td>0.5</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>24</td><td>cis-α-Bergamotene</td><td>1410</td><td>1411</td><td>1573</td><td>0.751</td><td>0.1</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>25</td><td>(E)-β-Caryophyllene</td><td>1419</td><td>1417</td><td>1598</td><td>0.751</td><td>11.7</td><td>17.1</td><td>22.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>26</td><td>Precocene</td><td>1428</td><td>1433</td><td>2070</td><td>0.815</td><td>0.2</td><td>0.3</td><td>0.3</td><td>RI, MS</td></tr><tr><td>27</td><td>α-Guaiene</td><td>1442</td><td>1435</td><td>1608</td><td>0.751</td><td>0.1</td><td>0.1</td><td>tr</td><td>RI, MS</td></tr><tr><td>28</td><td>(E)-β-Farnesene</td><td>1449</td><td>1446</td><td>1669</td><td>0.751</td><td>0.6</td><td>0.5</td><td>0.5</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>29</td><td>α-Humulene</td><td>1449</td><td>1449</td><td>1669</td><td>0.751</td><td>0.9</td><td>1.1</td><td>1.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>30</td><td>α-Curcumene</td><td>1471</td><td>1470</td><td>1776</td><td>0.707</td><td>11.6</td><td>12.4</td><td>11.9</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>31</td><td>γ-Curcumene</td><td>1472</td><td>1472</td><td>1694</td><td>0.751</td><td>24.8</td><td>22.2</td><td>23.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>32</td><td>Germacrene D</td><td>1476</td><td>1474</td><td>1709</td><td>0.751</td><td>0.5</td><td>1.0</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>33</td><td>β-Selinene</td><td>1481</td><td>1478</td><td>1719</td><td>0.751</td><td>0.1</td><td>0.3</td><td>3.9</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>34</td><td>γ-Humulene</td><td>1483</td><td>1481</td><td>1728</td><td>0.751</td><td>0.1</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>35</td><td>4-epi-Cubebol</td><td>1489</td><td>1485</td><td>1881</td><td>0.787</td><td>0.1</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>36</td><td>α-Selinene</td><td>1489</td><td>1490</td><td>1723</td><td>0.751</td><td>0.3</td><td>0.5</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>37</td><td>α-Muurolene</td><td>1491</td><td>1492</td><td>1732</td><td>0.751</td><td>0.1</td><td>0.2</td><td>0.3</td><td>RI, MS</td></tr><tr><td>38</td><td>β-Bisabolene</td><td>1500</td><td>1500</td><td>1727</td><td>0.751</td><td>0.2</td><td>0.4</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>39</td><td>γ-Cadinene</td><td>1506</td><td>1506</td><td>1761</td><td>0.751</td><td>0.2</td><td>0.1</td><td>0.3</td><td>RI, MS</td></tr><tr><td>40</td><td>δ-Cadinene</td><td>1514</td><td>1513</td><td>1757</td><td>0.751</td><td>0.5</td><td>0.8</td><td>0.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>41</td><td>Italicene oxide</td><td>1525</td><td>1521</td><td>1858</td><td>0.791</td><td>0.1</td><td>0.1</td><td>0.2</td><td>RI, MS</td></tr><tr><td>42</td><td>Geranyl 2-methylbutyrate</td><td>1562</td><td>1558</td><td>1861</td><td>0.819</td><td>1.7</td><td>0.9</td><td>0.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>43</td><td>Spathulenol</td><td>1566</td><td>1563</td><td>2120</td><td>0.791</td><td>0.1</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>44</td><td>Neryl isovalerate</td><td>1568</td><td>1564</td><td>1881</td><td>0.819</td><td>6.2</td><td>2.6</td><td>1.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>45</td><td>Caryophyllene oxide</td><td>1570</td><td>1569</td><td>1978</td><td>0.791</td><td>1.4</td><td>1.1</td><td>2.9</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>46</td><td>Globulol</td><td>1578</td><td>1573</td><td>2061</td><td>0.781</td><td>0.1</td><td>0.3</td><td>0.2</td><td>RI, MS</td></tr><tr><td>47</td><td>Viridiflorol</td><td>1580</td><td>1591</td><td>2080</td><td>0.781</td><td>0.1</td><td>0.4</td><td>0.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>48</td><td>neo-Intermedeol</td><td>1601</td><td>1603</td><td>2145</td><td>0.781</td><td>tr</td><td>0.1</td><td>tr</td><td>RI, MS</td></tr><tr><td>49</td><td>1,10-diepi-Cubenol</td><td>1605</td><td>1610</td><td>2054</td><td>0.781</td><td>0.1</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>50</td><td>Intermedeol</td><td>1636</td><td>1637</td><td>2247</td><td>0.781</td><td>0.2</td><td>0.3</td><td>0.3</td><td>RI, MS</td></tr><tr><td>51</td><td>Geranyl tiglate</td><td>1649</td><td>1647</td><td>2070</td><td>0.829</td><td>0.2</td><td>0.1</td><td>0.2</td><td>RI, MS</td></tr><tr><td>52</td><td>Neryl tiglate</td><td>1652</td><td>1656</td><td>2091</td><td>0.829</td><td>0.4</td><td>0.2</td><td>0.1</td><td>RI, MS</td></tr><tr><td>53</td><td>α-Bisabolol</td><td>1668</td><td>1665</td><td>2213</td><td>0.781</td><td>0.5</td><td>0.3</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>54</td><td>Curcuphenol</td><td>1684</td><td>1676</td><td>2600</td><td>0.746</td><td>1.9</td><td>1.3</td><td>1.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>55</td><td>Curcuphenyl acetate</td><td>1694</td><td>1690</td><td>2626</td><td>0.781</td><td>6.4</td><td>5.6</td><td>10.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>56</td><td>Pentadecanal</td><td>1695</td><td>1694</td><td>2041</td><td>0.764</td><td>-</td><td>0.2</td><td>0.2</td><td>RI, MS</td></tr><tr><td>57</td><td>Xanthorrhizol</td><td>1728</td><td>1737</td><td>-</td><td>0.746</td><td>0.5</td><td>0.2</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>58</td><td>Xanthorrhizyl acetate</td><td>1767</td><td>1743</td><td>-</td><td>0.781</td><td>6.2</td><td>3.3</td><td>1.3</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>59</td><td>Falcarinol</td><td>2000</td><td>1983</td><td>-</td><td>0.797</td><td>-</td><td>0.2</td><td>-</td><td>RI, MS</td></tr><tr><td>60</td><td>(E)-Phytol</td><td>2099</td><td>2097</td><td>2614</td><td>0.748</td><td>0.2</td><td>-</td><td>0.1</td><td>RI, MS</td></tr></tbody></table>
<table><caption>**Table 2.** *Cont.*</caption><thead><tr><th>N°</th><th>Compounds</th><th>RIa<sup>L</sup></th><th>RIa</th><th>RIp</th><th>RRF</th><th>A (%)<br>R1</th><th>Y-A (%)<br>R2</th><th>K (%)<br>R3</th><th>Identification</th></tr></thead><tbody><tr><td></td><td>Hydrocarbon<br>monoterpenes</td><td></td><td></td><td></td><td></td><td>8.1</td><td>11.5</td><td>2.7</td><td></td></tr><tr><td></td><td>Oxygenated<br>monoterpenes</td><td></td><td></td><td></td><td></td><td>10.2</td><td>4.5</td><td>3.3</td><td></td></tr><tr><td></td><td>Hydrocarbon<br>sesquiterpenes</td><td></td><td></td><td></td><td></td><td>59.4</td><td>67.6</td><td>72.3</td><td></td></tr><tr><td></td><td>Oxygenated<br>sesquiterpenes</td><td></td><td></td><td></td><td></td><td>17.7</td><td>13.3</td><td>18.7</td><td></td></tr><tr><td></td><td>Other compounds</td><td></td><td></td><td></td><td></td><td>0.2</td><td>0.4</td><td>0.3</td><td></td></tr><tr><td></td><td>Total identified</td><td></td><td></td><td></td><td></td><td>95.6</td><td>97.3</td><td>97.3</td><td></td></tr></tbody></table>

Order of elution and percentages are given on an apolar column (BP-1), except components with an asterisk (*), where percentages are taken on a polar column (BP-20). RIa<sup>L</sup>: apolar column retention indices from the literature [24–26]; RIa, RIp: retention indices measured on an apolar and polar capillary column, respectively. RRF: relative response factors calculated using methyl octanoate as internal standard. The relative proportions of constituent are expressed in g/100 g. tr: traces level (<0.05%). A: Adiopodoumé Forest; Y-A: Yapo-Abbé Forest; K: Korhogo.; (-): not detected.

## 3.2. Chemical Composition of Stem Essential Oil

The chemical composition of the stem essential oil from *S. nodiflora* is dominated by hydrocarbon monoterpenes (23.2–61.1%) and hydrocarbon sesquiterpenes (22.9–49.5%). Fifty-one constituents representing 92.6–97.6% of the chemical composition were identified. Samples S1, S2a and S3 are rich in myrcene (19.6–22.6%) and limonene (18.3–22.1%), followed by β-pinene (5.1–11.5%), germacrene D (0.2–10.5%), β-elemene (7.6–9.2%), (E)-β-caryophyllene (7.1–8.1%), α-pinene (2.5–4.5%) and bicyclogermacrene (0.3–4.0%). As for sample S2b, the main constituents are thymol (12.7%), germacrene D (12.2%), β-elemene (11.8%), limonene (9.0%), (E)-β-caryophyllene (9.0%), myrcene (8.5%) and bicyclogermacrene (7.6%) (Table 3). Thus, two chemical compositions appear for the stem essential oil, differing by the presence of thymol in appreciable content in one of the four oil samples. This difference could be related to the vegetative stage of the plant, since samples S2a and S2b from the same location do not have the same composition.

The stem essential oil sample from Nigeria, dominated by limonene (14.9%), α-santalene (9.0%), *n*-hexadecane (3.0%) and *n*-tetradecane (3.0%), differs from those of the present study [14]. Indeed, α-santalene, *n*-hexadecane and *n*-tetradecane are absent from our samples, while, in the Nigerian oil sample, thymol, β-pinene, germacrene D, β-elemene, bicyclogermacrene and α-pinene were not detected; additionally, there was a relatively low content of myrcene (1.5%) and (E)-β-caryophyllene (1.5%). Thus, the stem essential oil from *S. nodiflora* of an Ivorian origin showed original chemical compositions.

<table><caption>**Table 3.** Chemical composition of stem essential oil from *Synedrella nodiflora*.</caption><thead><tr><th>N°</th><th>Compounds</th><th>RIa<sup>L</sup></th><th>RIa</th><th>RIp</th><th>RRF</th><th>A (%)<br>S1</th><th>Y-A (%)<br>S2a<br>S2b</th><th>K (%)<br>S3</th><th>Identification</th></tr></thead><tbody><tr><td>1</td><td>α-Pinene</td><td>934</td><td>931</td><td>1020</td><td>0.765</td><td>4.5</td><td>2.9</td><td>0.5</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>2</td><td>Camphene</td><td>947</td><td>945</td><td>1071</td><td>0.765</td><td>0.4</td><td>0.3</td><td>0.1</td><td>RI, MS</td></tr><tr><td>3</td><td>Sabinene</td><td>968</td><td>966</td><td>1127</td><td>0.765</td><td>0.6</td><td>0.8</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>4</td><td>β-Pinene</td><td>973</td><td>971</td><td>1116</td><td>0.765</td><td>9.9</td><td>11.5</td><td>3.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>5</td><td>Myrcene</td><td>983</td><td>981</td><td>1166</td><td>0.765</td><td>22.6</td><td>19.6</td><td>8.5</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>6</td><td>α-Phellandrene</td><td>999</td><td>998</td><td>1170</td><td>0.765</td><td>0.1</td><td>0.1</td><td>tr</td><td>RI, MS</td></tr><tr><td>7</td><td>α-Terpinene</td><td>1010</td><td>1010</td><td>1186</td><td>0.765</td><td>-</td><td>0.1</td><td>0.3</td><td>RI, MS</td></tr><tr><td>8</td><td>p-Cymene</td><td>1015</td><td>1012</td><td>1276</td><td>0.698</td><td>-</td><td>-</td><td>0.4</td><td>RI, MS</td></tr><tr><td>9</td><td>β-Phellandrene *</td><td>1021</td><td>1022</td><td>1215</td><td>0.765</td><td>1.2</td><td>1.4</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>10</td><td>Limonene *</td><td>1024</td><td>1022</td><td>1206</td><td>0.765</td><td>21.5</td><td>18.3</td><td>9.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>11</td><td>(E)-β-Ocimene</td><td>1038</td><td>1035</td><td>1254</td><td>0.765</td><td>0.2</td><td>0.2</td><td>0.1</td><td>RI, MS</td></tr></tbody></table>
<table><caption>**Table 3. Cont.**</caption><thead><tr><th>N°</th><th>Compounds</th><th>RIaL</th><th>RIa</th><th>RIp</th><th>RRF</th><th>A (%)<br>S1</th><th>Y-A (%)<br>S2a</th><th>K (%)<br>S3</th><th>Identification</th></tr></thead><tbody><tr><td>12</td><td>γ-Terpinene</td><td>1050</td><td>1049</td><td>1250</td><td>0.765</td><td>-</td><td>tr</td><td>0.2</td><td>RI, MS</td></tr><tr><td>13</td><td>Terpinolene</td><td>1079</td><td>1079</td><td>1278</td><td>0.765</td><td>0.1</td><td>-</td><td>-</td><td>RI, MS</td></tr><tr><td>14</td><td>Terpinen-4-ol</td><td>1164</td><td>1163</td><td>1603</td><td>0.809</td><td>-</td><td>0.1</td><td>0.3</td><td>RI, MS</td></tr><tr><td>15</td><td>α-Terpineol</td><td>1175</td><td>1174</td><td>1697</td><td>0.809</td><td>-</td><td>0.1</td><td>0.2</td><td>RI, MS</td></tr><tr><td>16</td><td>Nerol</td><td>1216</td><td>1209</td><td>1793</td><td>0.809</td><td>-</td><td>-</td><td>tr</td><td>RI, MS</td></tr><tr><td>17</td><td>Neral</td><td>1220</td><td>1215</td><td>1682</td><td>0.817</td><td>-</td><td>-</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>18</td><td>Geraniol</td><td>1238</td><td>1236</td><td>1848</td><td>0.809</td><td>-</td><td>-</td><td>0.2</td><td>RI, MS</td></tr><tr><td>19</td><td>Geranial</td><td>1247</td><td>1243</td><td>1732</td><td>0.817</td><td>-</td><td>-</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>20</td><td>Thymol</td><td>1271</td><td>1268</td><td>2188</td><td>0.755</td><td>-</td><td>0.2</td><td>12.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>21</td><td>Bornyl acetate</td><td>1270</td><td>1270</td><td>1582</td><td>0.849</td><td>0.4</td><td>0.3</td><td>-</td><td>RI, MS</td></tr><tr><td>22</td><td>Bicycloelemene</td><td>1336</td><td>1334</td><td>1482</td><td>0.751</td><td>-</td><td>0.1</td><td>0.3</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>23</td><td>α-Cubebene</td><td>1352</td><td>1348</td><td>1459</td><td>0.751</td><td>-</td><td>tr</td><td>0.2</td><td>RI, MS</td></tr><tr><td>24</td><td>Cyclosativene</td><td>1368</td><td>1369</td><td>1483</td><td>0.751</td><td>-</td><td>0.6</td><td>tr</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>25</td><td>α-Copaene</td><td>1375</td><td>1375</td><td>1493</td><td>0.751</td><td>0.6</td><td>0.2</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>26</td><td>β-Cubebene*</td><td>1383</td><td>1387</td><td>1540</td><td>0.751</td><td>0.6</td><td>0.4</td><td>0.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>27</td><td>β-Elemene*</td><td>1388</td><td>1387</td><td>1591</td><td>0.751</td><td>9.2</td><td>8.0</td><td>11.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>28</td><td>α-Isocomene</td><td>1388</td><td>1389</td><td>1536</td><td>0.751</td><td>tr</td><td>tr</td><td>-</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>29</td><td>Cyperene</td><td>1398</td><td>1399</td><td>1528</td><td>0.751</td><td>-</td><td>0.5</td><td>tr</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>30</td><td>α-Gurjunene</td><td>1405</td><td>1409</td><td>1531</td><td>0.751</td><td>-</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>31</td><td>(E)-β-Caryophyllene</td><td>1419</td><td>1417</td><td>1598</td><td>0.751</td><td>7.1</td><td>7.1</td><td>9.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>32</td><td>Precocene</td><td>1428</td><td>1433</td><td>2070</td><td>0.815</td><td>-</td><td>0.6</td><td>0.3</td><td>tr</td></tr><tr><td>33</td><td>(E)-β-Farnesene</td><td>1449</td><td>1446</td><td>1669</td><td>0.751</td><td>-</td><td>0.2</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>34</td><td>α-Humulene</td><td>1449</td><td>1449</td><td>1669</td><td>0.751</td><td>0.8</td><td>0.7</td><td>1.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>35</td><td>α-Curcumene</td><td>1471</td><td>1470</td><td>1776</td><td>0.707</td><td>-</td><td>1.8</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>36</td><td>γ-Curcumene</td><td>1472</td><td>1472</td><td>1694</td><td>0.751</td><td>0.4</td><td>3.9</td><td>0.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>37</td><td>Germacrene D</td><td>1476</td><td>1474</td><td>1709</td><td>0.751</td><td>10.5</td><td>6.3</td><td>12.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>38</td><td>β-Selinene</td><td>1481</td><td>1481</td><td>1719</td><td>0.751</td><td>0.6</td><td>0.4</td><td>1.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>39</td><td>4-epi-Cubebol</td><td>1489</td><td>1485</td><td>1881</td><td>0.787</td><td>-</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>40</td><td>Bicyclogermacrene</td><td>1490</td><td>1491</td><td>1733</td><td>0.751</td><td>4.0</td><td>4.0</td><td>7.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>41</td><td>β-Bisabolene</td><td>1500</td><td>1500</td><td>1727</td><td>0.751</td><td>1.5</td><td>1.2</td><td>2.3</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>42</td><td>δ-Cadinene</td><td>1514</td><td>1513</td><td>1757</td><td>0.751</td><td>0.2</td><td>0.4</td><td>0.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>43</td><td>β-Elemol</td><td>1536</td><td>1534</td><td>2077</td><td>0.781</td><td>-</td><td>-</td><td>0.6</td><td>tr</td></tr><tr><td>44</td><td>Spathulenol</td><td>1566</td><td>1563</td><td>2119</td><td>0.791</td><td>-</td><td>0.4</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>45</td><td>Neryl isovalerate</td><td>1568</td><td>1564</td><td>1881</td><td>0.819</td><td>-</td><td>0.5</td><td>-</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>46</td><td>Caryophyllene oxide</td><td>1570</td><td>1569</td><td>1978</td><td>0.791</td><td>-</td><td>0.3</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>47</td><td>Intermedeol</td><td>1636</td><td>1637</td><td>2247</td><td>0.781</td><td>0.6</td><td>0.6</td><td>1.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>48</td><td>Curcuphenyl acetate</td><td>1694</td><td>1690</td><td>2626</td><td>0.781</td><td>-</td><td>1.6</td><td>0.3</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>49</td><td>Benzyl benzoate</td><td>1733</td><td>1722</td><td>2620</td><td>0.770</td><td>-</td><td>tr</td><td>2.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>50</td><td>Xanthorrhizyl acetate</td><td>1767</td><td>1743</td><td>-</td><td>0.781</td><td>tr</td><td>tr</td><td>tr</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>51</td><td>(E)-Phytol</td><td>2099</td><td>2097</td><td>2614</td><td>0.748</td><td>-</td><td>0.2</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td></td><td>Hydrocarbon<br>monoterpenes</td><td></td><td></td><td></td><td>61.1</td><td></td><td>55.2</td><td>23.2</td><td>54.6</td></tr><tr><td></td><td>Oxygenated<br>monoterpenes</td><td></td><td></td><td></td><td>0.4</td><td></td><td>1.2</td><td>13.6</td><td>7.8</td></tr><tr><td></td><td>Hydrocarbon<br>sesquiterpenes</td><td></td><td></td><td></td><td>35.5</td><td></td><td>36.5</td><td>49.5</td><td>22.9</td></tr><tr><td></td><td>Oxygenated<br>sesquiterpenes</td><td></td><td></td><td></td><td>0.6</td><td></td><td>3.0</td><td>3.6</td><td>10.6</td></tr><tr><td></td><td>Other compounds</td><td></td><td></td><td></td><td>0.0</td><td></td><td>0.2</td><td>2.7</td><td>1.5</td></tr><tr><td></td><td>Total identified</td><td></td><td></td><td></td><td>97.6</td><td></td><td>96.1</td><td>92.6</td><td>97.4</td></tr></tbody></table>

Order of elution and percentages are given on an apolar column (BP-1), except components with an asterisk (*), where percentages are taken on a polar column (BP-20). RIaL: apolar column retention indices from the literature [24–26]; RIa, RIp: retention indices measured on an apolar and polar capillary column, respectively. RRF: relative response factors calculated using methyl octanoate as the internal standard. The relative proportions of constituent are expressed in g/100 g. tr: traces level (<0.05%). A: Adiopodoumé Forest; Y-A: Yapo-Abbé Forest; K: Korhogo; (-): not detected.
### 3.3. Chemical Composition of Leaf Essential Oil

Forty-nine compounds, accounting for 93.3–98.8% of the whole chemical composition of the seven leaf essential oil samples, were identified. This essential oil mainly consists of hydrocarbon sesquiterpenes (59.1–86.1%) and lower contents of hydrocarbon monoterpenes (3.4–27.1%). (E)-β-caryophyllene (20.0–30.3%) and Germacrene D (7.7–33.6%) are the predominant compounds, followed by bicyclogermacrene (2.4–7.2%), β-cubebene (2.7–7.2%) and β-elemene (3.3–5.2%). However, only samples L1a and L1b from Adiopodoumé Forest contain thianthrene (2.8 and 0.6%, respectively). They also have an interesting amount of α-isocomene (6.7 and 1.1%, respectively), while L2a, L2b and L2c from Yapo-Abbé Forest exhibit appreciable thymol contents (3.0–8.7%). Sample L2c exhibited significant proportions of limonene (12.1%) and myrcene (8.0%). Samples L3a and L3b from Korhogo showed a relatively low content of germacrene D (10.0 and 7.7%, respectively vs. 21.2–33.6% for L1a-L2c). Significant amounts of (E)-phytol, a diterpene, have also been identified in samples L2a, L2c, L3a and L3b (2.2, 3.6, 4.7 and 5.1%, respectively) (Table 4). Hence, despite the predominance of (E)-β-caryophyllene and Germacrene D, quantitative differences are observable between the samples. The harvest sites and vegetative stage of the plant could be possible factors in this chemical variation.

Although a previous study conducted in Côte d'Ivoire on a single sample of leaf essential oil reported similar chemical composition with β-caryophyllene (19.5%), germacrene D (17.63%), caryophyllene oxide (10.5%) and β-elemene (9.80%) as major compounds, notable quantitative and qualitative variations are observable. Indeed, there is a low proportion of caryophyllene oxide in our samples (0.7–4.2%) compared to the previous study (10.5%). Qualitatively, some compounds that featured significantly in our samples, such as myrcene, thymol, α-isocomene, precocene, benzyl benzoate, thianthrene and (E)-phytol, were not detected in the previous study [15]. These quantitative and qualitative variations could be explained by differences in harvest sites and seasons. Moreover, the leaf essential oil from Côte d'Ivoire differs from those of Fiji and India. Germacrene D (21.2–33.6% in our samples) accounted only for 7.6 and 1.27% in oils from Fiji and India, respectively, whereas (E)-β-farnesene (11.9 and 22.75%, respectively Fiji and India) did not exceed 1.2% in our samples. Also, qualitative variations were observable through many compounds detected in our samples but absent from the Fiji and India chemical compositions, and conversely [12,13]. Combined factors, like differences in climate, vegetation, relief and harvest season, could be responsible for the observed variations.

<table><caption>**Table 4.** Chemical composition of leaf essential oil from *Synedrella nodiflora*.</caption><thead><tr><th rowspan="2">N°</th><th rowspan="2">Compounds</th><th rowspan="2">RIaL</th><th rowspan="2">RIa</th><th rowspan="2">RIp</th><th rowspan="2">RRF</th><th colspan="2">A (%)</th><th colspan="3">Y-A (%)</th><th colspan="2">K (%)</th><th rowspan="2">Identification</th></tr><tr><th>L1a</th><th>L1b</th><th>L2a</th><th>L2b</th><th>L2c</th><th>L3a</th><th>L3b</th></tr></thead><tbody><tr><td>1</td><td>α-Pinene</td><td>934</td><td>931</td><td>1020</td><td>0.765</td><td>0.2</td><td>0.6</td><td>0.2</td><td>0.2</td><td>1.7</td><td>0.8</td><td>1.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>2</td><td>Camphene</td><td>947</td><td>945</td><td>1071</td><td>0.765</td><td>-</td><td>0.3</td><td>tr</td><td>tr</td><td>0.3</td><td>0.1</td><td>0.2</td><td>RI, MS</td></tr><tr><td>3</td><td>Sabinene</td><td>968</td><td>966</td><td>1127</td><td>0.765</td><td>-</td><td>0.2</td><td>0.1</td><td>tr</td><td>0.4</td><td>0.2</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>4</td><td>β-Pinene</td><td>973</td><td>971</td><td>1116</td><td>0.765</td><td>0.4</td><td>1.4</td><td>0.7</td><td>0.5</td><td>3.6</td><td>1.0</td><td>1.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>5</td><td>Myrcene</td><td>983</td><td>981</td><td>1166</td><td>0.765</td><td>1.6</td><td>3.6</td><td>2.0</td><td>1.1</td><td>8.0</td><td>4.4</td><td>6.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>6</td><td>p-Cymene</td><td>1015</td><td>1012</td><td>1276</td><td>0.698</td><td>-</td><td>-</td><td>0.1</td><td>0.1</td><td>0.1</td><td>0.1</td><td>0.2</td><td>RI, MS</td></tr><tr><td>7</td><td>β-Phellandrene *</td><td>1021</td><td>1022</td><td>1215</td><td>0.765</td><td>0.1</td><td>0.3</td><td>0.2</td><td>0.1</td><td>0.8</td><td>0.8</td><td>0.5</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>8</td><td>Limonene *</td><td>1024</td><td>1022</td><td>1206</td><td>0.765</td><td>2.0</td><td>5.1</td><td>2.2</td><td>1.4</td><td>12.1</td><td>4.4</td><td>4.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>9</td><td>(E)-β-Ocimene</td><td>1038</td><td>1035</td><td>1254</td><td>0.765</td><td>-</td><td>tr</td><td>tr</td><td>-</td><td>0.1</td><td>-</td><td>0.1</td><td>RI, MS</td></tr><tr><td>10</td><td>Terpinolene</td><td>1079</td><td>1079</td><td>1278</td><td>0.765</td><td>2.3</td><td>0.4</td><td>tr</td><td>-</td><td>-</td><td>0.2</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>11</td><td>Nerol</td><td>1216</td><td>1210</td><td>1793</td><td>0.809</td><td>-</td><td>-</td><td>-</td><td>-</td><td>0.1</td><td>0.1</td><td>-</td><td>RI, MS</td></tr><tr><td>12</td><td>Neral</td><td>1220</td><td>1215</td><td>1682</td><td>0.817</td><td>-</td><td>-</td><td>tr</td><td>tr</td><td>0.3</td><td>1.7</td><td>tr</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>13</td><td>Geraniol</td><td>1238</td><td>1234</td><td>1849</td><td>0.809</td><td>-</td><td>-</td><td>0.1</td><td>0.1</td><td>0.3</td><td>0.5</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>14</td><td>Geranial</td><td>1247</td><td>1242</td><td>1731</td><td>0.817</td><td>-</td><td>-</td><td>tr</td><td>tr</td><td>0.5</td><td>2.7</td><td>-</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>15</td><td>Thymol</td><td>1271</td><td>1268</td><td>2188</td><td>0.755</td><td>0.5</td><td>0.2</td><td>8.7</td><td>4.8</td><td>3.0</td><td>0.2</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr></tbody></table>
<table><caption>**Table 4. Cont.**</caption><thead><tr><th rowspan="2">N°</th><th rowspan="2">Compounds</th><th rowspan="2">RIa<sup>L</sup></th><th rowspan="2">RIa</th><th rowspan="2">RIp</th><th rowspan="2">RRF</th><th colspan="2">A (%)</th><th colspan="2">Y-A (%)</th><th colspan="2">K (%)</th><th rowspan="2">Identification</th></tr><tr><th>L1a</th><th>L1b</th><th>L2a</th><th>L2b</th><th>L2c</th><th>L3a</th><th>L3b</th></tr></thead><tbody><tr><td>16</td><td>Bornyl acetate</td><td>1270</td><td>1270</td><td>1582</td><td>0.849</td><td>0.2</td><td>0.3</td><td>-</td><td>0.1</td><td>0.6</td><td>0.1</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>17</td><td>Bicycloelemene</td><td>1336</td><td>1334</td><td>1482</td><td>0.751</td><td>-</td><td>0.2</td><td>0.3</td><td>0.4</td><td>0.2</td><td>0.1</td><td>0.1</td><td>RI, MS</td></tr><tr><td>18</td><td>α-Cubebene</td><td>1352</td><td>1347</td><td>1472</td><td>0.751</td><td>1.5</td><td>0.2</td><td>0.1</td><td>0.1</td><td>0.1</td><td>0.1</td><td>0.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>19</td><td>α-Copaene</td><td>1375</td><td>1375</td><td>1493</td><td>0.751</td><td>1.0</td><td>0.9</td><td>0.6</td><td>0.6</td><td>0.5</td><td>0.9</td><td>1.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>20</td><td>β-Bourbonene</td><td>1381</td><td>1385</td><td>1520</td><td>0.751</td><td>0.8</td><td>0.8</td><td>0.9</td><td>1.1</td><td>0.3</td><td>3.7</td><td>2.9</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>21</td><td>β-Cubebene *</td><td>1383</td><td>1387</td><td>1540</td><td>0.751</td><td>4.0</td><td>4.6</td><td>3.9</td><td>4.5</td><td>2.7</td><td>7.2</td><td>3.9</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>22</td><td>β-Elemene *</td><td>1388</td><td>1387</td><td>1591</td><td>0.751</td><td>5.2</td><td>4.3</td><td>3.9</td><td>4.3</td><td>3.3</td><td>3.5</td><td>3.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>23</td><td>α-Isocomene</td><td>1388</td><td>1389</td><td>1536</td><td>0.751</td><td>6.7</td><td>1.1</td><td>-</td><td>-</td><td>-</td><td>0.1</td><td>tr</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>24</td><td>α-Gurjunene</td><td>1405</td><td>1409</td><td>1531</td><td>0.751</td><td>3.2</td><td>0.5</td><td>0.2</td><td>0.2</td><td>0.1</td><td>0.2</td><td>0.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>25</td><td>(E)-β-Caryophyllene</td><td>1419</td><td>1417</td><td>1598</td><td>0.751</td><td>24.3</td><td>26.0</td><td>25.2</td><td>30.3</td><td>20.0</td><td>26.9</td><td>29.4</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>26</td><td>β-Copaene</td><td>1427</td><td>1428</td><td>1582</td><td>0.751</td><td>0.2</td><td>0.3</td><td>0.3</td><td>0.4</td><td>0.2</td><td>0.7</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>27</td><td>Precocene</td><td>1428</td><td>1433</td><td>2070</td><td>0.815</td><td>1.3</td><td>0.4</td><td>0.2</td><td>0.3</td><td>1.9</td><td>1.5</td><td>0.8</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>28</td><td>(E)-β-Farnesene</td><td>1449</td><td>1446</td><td>1669</td><td>0.751</td><td>0.9</td><td>1.2</td><td>0.7</td><td>0.8</td><td>0.7</td><td>0.9</td><td>0.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>29</td><td>α-Humulene</td><td>1449</td><td>1449</td><td>1669</td><td>0.751</td><td>2.9</td><td>2.9</td><td>2.5</td><td>3.1</td><td>2.2</td><td>2.6</td><td>3.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>30</td><td>Germacrene D</td><td>1476</td><td>1474</td><td>1709</td><td>0.751</td><td>28.1</td><td>33.6</td><td>27.7</td><td>29.7</td><td>21.2</td><td>10.0</td><td>7.7</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>31</td><td>β-Selinene</td><td>1481</td><td>1481</td><td>1719</td><td>0.751</td><td>-</td><td>-</td><td>-</td><td>0.3</td><td>0.3</td><td>0.2</td><td>0.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>32</td><td>4-epi-Cubebol</td><td>1489</td><td>1485</td><td>1881</td><td>0.787</td><td>-</td><td>-</td><td>0.2</td><td>0.3</td><td>0.2</td><td>0.3</td><td>1.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>33</td><td>Bicyclogermacrene</td><td>1490</td><td>1491</td><td>1733</td><td>0.751</td><td>5.2</td><td>6.4</td><td>6.4</td><td>7.2</td><td>4.5</td><td>2.4</td><td>3.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>34</td><td>α-Muurolene</td><td>1491</td><td>1492</td><td>1732</td><td>0.751</td><td>-</td><td>-</td><td>-</td><td>0.4</td><td>0.3</td><td>0.2</td><td>0.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>35</td><td>(E,E)-α-Farnesene</td><td>1496</td><td>1498</td><td>1751</td><td>0.751</td><td>0.4</td><td>0.5</td><td>0.4</td><td>0.2</td><td>tr</td><td>0.2</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>36</td><td>β-Bisabolene</td><td>1500</td><td>1500</td><td>1727</td><td>0.751</td><td>-</td><td>-</td><td>0.4</td><td>0.3</td><td>0.2</td><td>0.7</td><td>1.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>37</td><td>δ-Cadinene</td><td>1514</td><td>1513</td><td>1757</td><td>0.751</td><td>0.4</td><td>0.4</td><td>0.5</td><td>0.7</td><td>0.4</td><td>0.5</td><td>3.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>38</td><td>β-Elemol</td><td>1536</td><td>1534</td><td>2077</td><td>0.781</td><td>-</td><td>-</td><td>0.4</td><td>0.3</td><td>0.1</td><td>0.4</td><td>0.5</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>39</td><td>Spathulenol</td><td>1566</td><td>1563</td><td>2119</td><td>0.791</td><td>0.4</td><td>0.1</td><td>0.6</td><td>0.1</td><td>0.6</td><td>1.2</td><td>1.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>40</td><td>Neryl isovalerate</td><td>1568</td><td>1566</td><td>1882</td><td>0.819</td><td>tr</td><td>tr</td><td>0.1</td><td>0.1</td><td>0.1</td><td>0.9</td><td>0.9</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>41</td><td>Caryophyllene oxide</td><td>1570</td><td>1569</td><td>1978</td><td>0.791</td><td>0.8</td><td>0.7</td><td>0.8</td><td>0.9</td><td>0.8</td><td>4.1</td><td>4.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>42</td><td>Isospathulenol</td><td>1625</td><td>1619</td><td>2195</td><td>0.791</td><td>-</td><td>-</td><td>0.2</td><td>0.1</td><td>0.1</td><td>0.3</td><td>0.3</td><td>RI, MS</td></tr><tr><td>43</td><td>τ-Cadinol</td><td>1626</td><td>1626</td><td>2167</td><td>0.781</td><td>-</td><td>-</td><td>0.3</td><td>0.2</td><td>tr</td><td>tr</td><td>0.6</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>44</td><td>Curcuphenol</td><td>1684</td><td>1677</td><td>2600</td><td>0.746</td><td>-</td><td>-</td><td>0.2</td><td>0.1</td><td>-</td><td>1.1</td><td>1.0</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>45</td><td>Benzyl benzoate</td><td>1733</td><td>1722</td><td>2620</td><td>0.770</td><td>-</td><td>-</td><td>1.2</td><td>1.0</td><td>-</td><td>0.1</td><td>tr</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>46</td><td>Thianthrene</td><td>1883</td><td>1876</td><td>-</td><td>0.890</td><td>2.8</td><td>0.6</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>47</td><td>Cembrene A</td><td>1959</td><td>1954</td><td>2245</td><td>0.744</td><td>-</td><td>-</td><td>0.6</td><td>0.3</td><td>0.1</td><td>0.3</td><td>0.2</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td>48</td><td>Falcarinol</td><td>2000</td><td>1983</td><td>-</td><td>0.797</td><td>-</td><td>-</td><td>0.5</td><td>tr</td><td>-</td><td>-</td><td>-</td><td>RI, MS</td></tr><tr><td>49</td><td>(E)-Phytol</td><td>2099</td><td>2097</td><td>2614</td><td>0.748</td><td>0.8</td><td>0.7</td><td>2.2</td><td>0.5</td><td>3.6</td><td>4.7</td><td>5.1</td><td>RI, MS, <sup>13</sup>C-NMR</td></tr><tr><td colspan="2">Hydrocarbon</td><td></td><td></td><td></td><td>6.6</td><td>11.9</td><td>5.5</td><td>3.4</td><td>27.1</td><td>12.0</td><td>15.3</td><td></td><td></td></tr><tr><td colspan="2">monoterpenes</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td colspan="2">Oxygenated</td><td></td><td></td><td></td><td>0.7</td><td>0.5</td><td>8.9</td><td>5.1</td><td>4.9</td><td>6.2</td><td>1.3</td><td></td><td></td></tr><tr><td colspan="2">monoterpenes</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td colspan="2">Hydrocarbon</td><td></td><td></td><td></td><td>86.1</td><td>84.3</td><td>74.2</td><td>84.9</td><td>59.1</td><td>62.6</td><td>63.8</td><td></td><td></td></tr><tr><td colspan="2">sesquiterpenes</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td colspan="2">Oxygenated</td><td></td><td></td><td></td><td>1.2</td><td>0.8</td><td>2.7</td><td>2.0</td><td>1.8</td><td>7.4</td><td>8.7</td><td></td><td></td></tr><tr><td colspan="2">sesquiterpenes</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td colspan="2">Other compounds</td><td></td><td></td><td></td><td>3.6</td><td>1.3</td><td>4.5</td><td>1.8</td><td>3.7</td><td>5.1</td><td>5.3</td><td></td><td></td></tr><tr><td colspan="2">Total identified</td><td></td><td></td><td></td><td>98.2</td><td>98.8</td><td>95.8</td><td>97.2</td><td>96.6</td><td>93.3</td><td>94.4</td><td></td><td></td></tr></tbody></table>

Order of elution and percentages are given on an apolar column (BP-1), except components with an asterisk (*), where percentages are taken on a polar column (BP-20). RIaL: apolar column retention indices from the literature [24–26]; RIa, RIp: retention indices measured on an apolar and polar capillary column, respectively. RRF: relative response factors calculated using methyl octanoate as the internal standard. The relative proportions of constituent are expressed in g/100 g. tr: traces level (<0.05%). A: Adiopodoumé Forest; Y-A: Yapo-Abbé Forest; K: Korhogo; (-): not detected.

### 3.4. Discussion about Statistical Analyses

Statistical analyses were carried out on the 14 essential oil compositions through hierarchical cluster analysis (HCA) and principal component analysis (PCA) to confirm the observed chemical variability. The dendrogram from the HCA displayed three distinct chemical compositions within the 14 investigated oil samples, as follows: group I (seven
leaf oil samples and stem oil sample S2b), group II (three stem oil samples) and group III (three root oil samples). The first and second principal factors of the PCA (F1: 47.40% and F2: 35.16%, respectively) accounted for 82.56% of the total variance of the chemical composition. The PCA map relative to the principal axes F1 and F2 confirmed the three groups observed in the dendrogram (Figure 1). Groups II and III are more homogenous than group I. However, considering the third main factor (F3: 9.17%), in a 3D PCA projection, principal axes F1, F2 and F3 account then for 91.74% of the total variance of the chemical composition, and stem oil sample S2b fits well into group II (Figure 2).

<figure><img src="image_4.png" /><figcaption>**Figure 1.** HCA dendrogram and PCA map of the 14 oil samples from *S. nodiflora*. (a) Hierarchical Cluster Analysis (HCA); (b) Principal Component Analysis (PCA) and biplot.</figcaption></figure>

<figure><img src="image_5.png" /><figcaption>**Figure 2.** 3D PCA map of the 14 oil samples from *S. nodiflora*.</figcaption></figure>

The mean contents (M) and the standard deviation (SD) of the major compounds of the different groups are reported on Table 5. The chemical composition of each organ is
homogeneous and appears to be not deeply influenced by the location. However, Korhogo leaf oil samples L3a and L3b and the Yapo-Abbé forest stem oil sample S2b exhibited slightly different chemical compositions.

<table><caption>**Table 5.** Main compounds of the three groups related to the three organs of *S. nodiflora*.</caption><thead><tr><th rowspan="2">Component <sup>[a]</sup></th><th colspan="3">Group I</th><th colspan="3">Group II</th><th colspan="3">Group III</th></tr><tr><th>M% ± SD</th><th>Min</th><th>Max</th><th>M% ± SD</th><th>Min</th><th>Max</th><th>M% ± SD</th><th>Min</th><th>Max</th></tr></thead><tbody><tr><td>α-Pinene</td><td>0.7 ± 0.6</td><td>0.2</td><td>1.7</td><td>2.6 ± 1.6</td><td>0.5</td><td>4.5</td><td>2.4 ± 1.8</td><td>1.0</td><td>4.4</td></tr><tr><td>β-Pinene</td><td>1.3 ± 1.1</td><td>0.4</td><td>3.6</td><td>7.4 ± 3.9</td><td>3.2</td><td>11.5</td><td>2.6 ± 1.8</td><td>1.0</td><td>4.6</td></tr><tr><td>Myrcene</td><td>3.8 ± 2.5</td><td>1.1</td><td>8.0</td><td>18.0 ± 6.4</td><td>8.5</td><td>22.6</td><td>1.0 ± 1.2</td><td>0.3</td><td>2.4</td></tr><tr><td>Limonene</td><td>4.6 ± 3.6</td><td>1.4</td><td>12.1</td><td>17.7 ± 6.1</td><td>9.0</td><td>22.1</td><td>0.8 ± 0.8</td><td>0.2</td><td>1.7</td></tr><tr><td>Thymol</td><td>2.5 ± 3.3</td><td>0.2</td><td>8.7</td><td>3.3 ± 6.3</td><td>-</td><td>12.7</td><td>0.4 ± 0.3</td><td>0.1</td><td>0.7</td></tr><tr><td>β-Cubebene *</td><td>4.4 ± 1.4</td><td>2.7</td><td>7.2</td><td>0.6 ± 0.2</td><td>0.4</td><td>0.8</td><td>-</td><td>-</td><td>-</td></tr><tr><td>β-Elemene *</td><td>4.0 ± 0.6</td><td>3.3</td><td>5.2</td><td>9.2 ± 1.9</td><td>7.6</td><td>11.8</td><td>1.0 ± 0.8</td><td>0.4</td><td>1.9</td></tr><tr><td>(E)-β-Caryophyllene</td><td>26.0 ± 3.4</td><td>20.0</td><td>30.3</td><td>8.0 ± 1.0</td><td>7.1</td><td>9.0</td><td>17.0 ± 5.3</td><td>11.7</td><td>22.2</td></tr><tr><td>α-Curcumene</td><td>-</td><td>-</td><td>-</td><td>0.7 ± 0.8</td><td>-</td><td>1.8</td><td>12.0 ± 0.4</td><td>11.6</td><td>12.4</td></tr><tr><td>γ-Curcumene</td><td>-</td><td>-</td><td>-</td><td>1.5 ± 1.6</td><td>0.4</td><td>3.9</td><td>23.5 ± 1.3</td><td>22.2</td><td>24.8</td></tr><tr><td>Germacrene D</td><td>22.6 ± 10.1</td><td>7.7</td><td>33.6</td><td>7.3 ± 5.3</td><td>0.2</td><td>12.2</td><td>0.6 ± 0.4</td><td>0.2</td><td>1.0</td></tr><tr><td>Bicyclogermacrene</td><td>5.0 ± 1.8</td><td>2.4</td><td>7.2</td><td>4.0 ± 3.0</td><td>0.3</td><td>7.6</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Neryl isovalerate</td><td>0.3 ± 0.4</td><td>-</td><td>0.9</td><td>0.4 ± 0.4</td><td>-</td><td>0.9</td><td>3.3 ± 2.6</td><td>1.2</td><td>6.2</td></tr><tr><td>Curcuphenyl acetate</td><td>-</td><td>-</td><td>-</td><td>0.5 ± 0.7</td><td>-</td><td>1.6</td><td>7.6 ± 2.7</td><td>5.6</td><td>10.7</td></tr><tr><td>Xanthorrhizyl acetate</td><td>-</td><td>-</td><td>-</td><td>0.3 ± 0.5</td><td>tr</td><td>1.0</td><td>3.6 ± 2.5</td><td>1.3</td><td>6.2</td></tr><tr><td>(E)-Phytol</td><td>2.5 ± 2.0</td><td>0.5</td><td>5.1</td><td>0.6 ± 0.6</td><td>-</td><td>1.3</td><td>0.1 ± 0.1</td><td>-</td><td>0.2</td></tr></tbody></table>

[a] Order of elution and percentages on apolar column (BP-1), except components with an asterisk (*), percentages on polar column (BP-20); M% ± SD: mean percentage and standard deviation; tr: traces level (<0.05%); (-): not detected.

Group I, consisting of the seven leaf oil samples, is dominated by (E)-β-caryophyllene (26.0 ± 3.4%) and germacrene D (22.6 ± 10.1%), followed by bicyclogermacrene (5.0 ± 1.8%). The four stem oil samples (group II) are characterized by monoterpene hydrocarbons such as myrcene (18.0 ± 6.4%), limonene (17.7 ± 6.1%) and β-pinene (7.4 ± 3.9%). In contrast, the root oil samples (group III) are characterized by the presence of γ-curcumene (23.5 ± 1.9%) and α-curcumene (12.0 ± 0.6%). Other compounds, such as curcuphenyl acetate (7.6 ± 2.7%), xanthorrhizyl acetate (3.6 ± 2.5%) and neryl isovalerate (3.3 ± 2.6%), are present in significant amounts. Apart from neryl isovalerate, all these compounds were not detected in leaf oil samples.

## 4. Conclusions

The chemical compositions of the root, stem and leaf essential oils from *S. nodiflora* were investigated, with the root oil composition being reported for the first time. A combination of GC(RI), GC-MS and ¹³C-NMR was used for the identification and quantification of the constituents, and different chemical profiles were observed for the three organs of the plant. The location did not deeply influence the chemical composition. Leaf oil samples were dominated by sesquiterpene hydrocarbons such as (E)-β-caryophyllene and germacrene D, while stem oil samples showed monoterpene hydrocarbons, myrcene and limonene as being the most abundant constituents. The root oil samples were characterized by the high amounts of γ-curcumene and α-curcumene.

**Author Contributions:** Conceptualization, D.A.K., T.A.Y. and F.T.; methodology, D.A.K., K.T. and F.T.; software, D.A.K. and M.P.; validation, J.B.B., A.B. and F.T.; formal analysis, D.A.K. and K.T.; data analysis, D.A.K., T.A.Y. and F.T.; essential oil investigation, D.A.K. and K.T.; writing—original draft preparation, D.A.K. and F.T.; writing—review and editing, D.A.K., T.A.Y., J.B.B. and F.T.; visualization, D.A.K. and M.P.; supervision, T.A.Y., A.B. and F.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.
**Data Availability Statement:** Data and samples of the essential oils are available from the authors.

**Acknowledgments:** The authors gratefully acknowledge H. Téré for his valuable help in the plant identification.

**Conflicts of Interest:** The authors declare no conflicts of interest.

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