**4.1 Essential oil of aerial parts of** *S. serrata*

**Table 2** shows the yield and composition results of the intense blue essential oil obtained from the aerial parts of individuals of *S. serrata* collected in three different populations distinct of the population sampled in a previous study of the chemical composition of oil of *S. serrata* from Guatemala [33]. The three populations are located in the highlands of western Guatemala. Extraction yields were between 0.2 and 0.3% (w/w) (**Table 3**), corresponding the highest yield to the SS4 oil from Santa Cruz del Quiché. A probable explanation for the difference in yields among the sampled populations is that the production of essential oil depends on the phenological stage, so that there is a greater production of oil in the flowering stage and lower production in the fruiting stage.

Another probable explanation could be edaphic factors affecting the production of secondary metabolites in general, but only after new investigations could the relationship between these factors and the production of essential oil and other metabolites be determined.

Regarding the chemical composition analyzed by GC/MS, 22 compounds were identified in the SS3 (94.7% of the total area) and SS4 (97.6% of the total area) oils and 18 compounds in the SS5 oil (98.4% of the total area). A chromatogram of the essential oil of SS4 is shown in **Figure 5**. The most abundant compound was the chamazulene in area percentages between 42 and 62%, with the highest percentage corresponding to the SS5 essential oil. The mass spectrum of chamazulene from the essential oil of sample SS4 is shown in **Figure 6**. The other compounds found in high percentage in the oil were germacrene D (4.4–15.3%), caryophyllene oxide (3.2–11.8%), (*E*)-nerolidol (3.9–7.1%), spathulenol (2.3–7.9%) and (*E*) caryophyllene (2.5–6.6%). The α-longipinene, frequently found in *Stevia* genus plants [8] that had not been reported in the essential oil of *S. serrata*, was found in the SS4 oil in 0.4%.

**209**

**Table 2.**

*Seed Propagation and Constituents of the Essential Oil of* Stevia serrata *Cav. from Guatemala*

The results confirm that essential oil of *S. serrata* with high content of chamazulene can be obtained from the different populations of the Guatemalan highlands. The authors consider that although the extraction yield in all the samples has been lower than 0.3%, the plant presents economic potential for its domestication for oil production in view of its high content of chamazulene and the presence in it of other components for which pharmacological activity has been reported.

*Composition of the essential oil of the aerial parts of S. serrata from three localities.*

*DOI: http://dx.doi.org/10.5772/intechopen.88221*


*Seed Propagation and Constituents of the Essential Oil of* Stevia serrata *Cav. from Guatemala DOI: http://dx.doi.org/10.5772/intechopen.88221*

#### **Table 2.**

*Essential Oils - Oils of Nature*

40–700 Da.

**3. Results**

**4. Discussion**

fruiting stage.

metabolites be determined.

**2.5 Gas chromatography coupled to mass spectrometry analyses (GC/MS)**

GC/MS analyses were performed using a chromatograph Shimadzu 2010 Plus system coupled with a Shimadzu QP-2010 Plus selective detector (MSD) and equipped with a DB5-MS capillary fused silica column (60 m, 0.25 mm I.D., 0.25 μm film thickness). The oven temperature program initiated at 60°C, then was raised by 3°C/min to 246°C, and then was held for 20 min. Other operating conditions were as follows: carrier gas, He (99.999%), with a flow rate of 1.03 mL/min; injector temperature, 220°C; split ratio of 1:50; and injection volume of 1 μL. Mass spectra were taken at 70 eV. The m/z values were recorded in the range of m/z

**Tables 2** and **3** present the results of yields and chemical composition of the essential oils of the three sampled populations of *S. serrata* and roots of plants obtained by seed propagation, respectively. Chamazulene was the major component of the essential oils of the aerial parts meanwhile α-longipinene was the compound

**Table 2** shows the yield and composition results of the intense blue essential oil obtained from the aerial parts of individuals of *S. serrata* collected in three different populations distinct of the population sampled in a previous study of the chemical composition of oil of *S. serrata* from Guatemala [33]. The three populations are located in the highlands of western Guatemala. Extraction yields were between 0.2 and 0.3% (w/w) (**Table 3**), corresponding the highest yield to the SS4 oil from Santa Cruz del Quiché. A probable explanation for the difference in yields among the sampled populations is that the production of essential oil depends on the phenological stage, so that there is a greater production of oil in the flowering stage and lower production in the

Another probable explanation could be edaphic factors affecting the production of secondary metabolites in general, but only after new investigations could the relationship between these factors and the production of essential oil and other

Regarding the chemical composition analyzed by GC/MS, 22 compounds were identified in the SS3 (94.7% of the total area) and SS4 (97.6% of the total area) oils and 18 compounds in the SS5 oil (98.4% of the total area). A chromatogram of the essential oil of SS4 is shown in **Figure 5**. The most abundant compound was the chamazulene in area percentages between 42 and 62%, with the highest percentage corresponding to the SS5 essential oil. The mass spectrum of chamazulene from the essential oil of sample SS4 is shown in **Figure 6**. The other compounds found in high percentage in the oil were germacrene D (4.4–15.3%), caryophyllene oxide (3.2–11.8%), (*E*)-nerolidol (3.9–7.1%), spathulenol (2.3–7.9%) and (*E*) caryophyllene (2.5–6.6%). The α-longipinene, frequently found in *Stevia* genus plants [8] that had not been reported in the essential oil of *S. serrata*, was found in

found in major proportion in the essential oil of the roots.

**4.1 Essential oil of aerial parts of** *S. serrata*

**208**

the SS4 oil in 0.4%.

*Composition of the essential oil of the aerial parts of S. serrata from three localities.*

The results confirm that essential oil of *S. serrata* with high content of chamazulene can be obtained from the different populations of the Guatemalan highlands. The authors consider that although the extraction yield in all the samples has been lower than 0.3%, the plant presents economic potential for its domestication for oil production in view of its high content of chamazulene and the presence in it of other components for which pharmacological activity has been reported.


#### **Table 3.**

*Composition of the essential oil of roots of propagated S. serrata.*

When comparing this source of essential oil with chamazulene content in the oil of *Matricaria recutita* L. (Asteraceae), which is obtained only from the flowers of this species [31], *S. serrata* is shown as a promising species because all aerial parts (leaves, stems, and flowers) produce essential oil with high chamazulene content.

**211**

*Seed Propagation and Constituents of the Essential Oil of* Stevia serrata *Cav. from Guatemala*

It is worth noting that the composition of the three oils is in congruence with the composition obtained by Simas et al. [33] of *S. serrata* from a population in the department of Sololá, presenting the same major compounds with some percentage

A seed propagation trial was carried out with seeds of plants of *S. serrata* collected from a population of Santa Lucía Utatlán, Sololá, from where the composition of essential oil with a high content of chamazulene had been previously reported [33]. The purpose of the trial was to evaluate the capability of propagation of the plants, generate new seeds, and extract and analyze the essential oil from the root. The interest in analyzing the root oil was due to the fact that in interviews with residents of the region, the authors had received information that previously the root of the plant had been used in traditional medicine for the treatment of stomach pain [33]. The seeds were germinated in peat moss, and then seedlings were transplanted to pots where they developed well with approximately 75% survival reaching 1 m height after 6 months. It is important to note that the cultivation experiment was carried out in Guatemala City, at an altitude of 1495 m, this being a

After obtaining the seeds during a plant vegetative stage, the roots were collected from which an essential oil with a light green color was obtained with a yield of 0.2% (w/w), and 25 compounds representing 95.8% of the total chromatographic area were identified (**Table 3**). The chromatogram of the essential oil of the roots is shown in **Figure 7**. Due to the green coloration of the oil, it was supposed that the chamazulene was absent in the oil, which was confirmed after the analysis by GC/MS. The major components of the root oil corresponded to α-longipinene (23.5%), germacrene D (22.2%), santolina triene (12.6%), and (*E*)-caryophyllene (8.1%). The mass spectrum

The common components between the root and the aerial parts oils were germacrene D and (*E*)-caryophyllene. The α-longipinene (**Figure 9**) was only

variations and the majority of compounds such as sesquiterpenoids.

*Chromatogram of the essential oil of S. serrata from SS4 sample obtained by GC/MS.*

**4.2 Essential oil of roots of propagated plants of** *S. serrata*

*Spectrum of chamazulene corresponding to the essential oil of sample SS4.*

lower altitude than in the region where the plant grows naturally.

of α-longipinene is shown in **Figure 8**.

*DOI: http://dx.doi.org/10.5772/intechopen.88221*

**Figure 5.**

**Figure 6.**

*Seed Propagation and Constituents of the Essential Oil of* Stevia serrata *Cav. from Guatemala DOI: http://dx.doi.org/10.5772/intechopen.88221*

#### **Figure 5.**

*Essential Oils - Oils of Nature*

**210**

**Table 3.**

When comparing this source of essential oil with chamazulene content in the oil of *Matricaria recutita* L. (Asteraceae), which is obtained only from the flowers of this species [31], *S. serrata* is shown as a promising species because all aerial parts (leaves, stems, and flowers) produce essential oil with high chamazulene content.

*Composition of the essential oil of roots of propagated S. serrata.*

*Chromatogram of the essential oil of S. serrata from SS4 sample obtained by GC/MS.*

#### **Figure 6.**

*Spectrum of chamazulene corresponding to the essential oil of sample SS4.*

It is worth noting that the composition of the three oils is in congruence with the composition obtained by Simas et al. [33] of *S. serrata* from a population in the department of Sololá, presenting the same major compounds with some percentage variations and the majority of compounds such as sesquiterpenoids.

#### **4.2 Essential oil of roots of propagated plants of** *S. serrata*

A seed propagation trial was carried out with seeds of plants of *S. serrata* collected from a population of Santa Lucía Utatlán, Sololá, from where the composition of essential oil with a high content of chamazulene had been previously reported [33]. The purpose of the trial was to evaluate the capability of propagation of the plants, generate new seeds, and extract and analyze the essential oil from the root. The interest in analyzing the root oil was due to the fact that in interviews with residents of the region, the authors had received information that previously the root of the plant had been used in traditional medicine for the treatment of stomach pain [33]. The seeds were germinated in peat moss, and then seedlings were transplanted to pots where they developed well with approximately 75% survival reaching 1 m height after 6 months. It is important to note that the cultivation experiment was carried out in Guatemala City, at an altitude of 1495 m, this being a lower altitude than in the region where the plant grows naturally.

After obtaining the seeds during a plant vegetative stage, the roots were collected from which an essential oil with a light green color was obtained with a yield of 0.2% (w/w), and 25 compounds representing 95.8% of the total chromatographic area were identified (**Table 3**). The chromatogram of the essential oil of the roots is shown in **Figure 7**. Due to the green coloration of the oil, it was supposed that the chamazulene was absent in the oil, which was confirmed after the analysis by GC/MS. The major components of the root oil corresponded to α-longipinene (23.5%), germacrene D (22.2%), santolina triene (12.6%), and (*E*)-caryophyllene (8.1%). The mass spectrum of α-longipinene is shown in **Figure 8**.

The common components between the root and the aerial parts oils were germacrene D and (*E*)-caryophyllene. The α-longipinene (**Figure 9**) was only found in one of the oils of the aerial parts in low percentage (0.4%), while the santolina triene (**Figure 9**) was not found in any of the oils of the aerial parts. As in the oil of aerial parts, sesquiterpenoids predominated in the root oil. Since the plant has been used in the past for the treatment of stomach pain, the authors consider it of value to carry out pharmacological activity tests with this oil in the near future.
