3.3 Chemical compositions of essential oils obtained from tropical plants grown in Colombia

CENIVAM has studied Colombian plants widely used in popular medicine or in culinary, for example, anise [14], oregano [15], rue [16, 17], and other species introduced from Asia, such as lemongrass, citronella, ginger, citrics [18–20], vetiver, and ylang-ylang [21–23], as well as several native species, among others, Copaifera officinalis [24], Spilanthes americana [25], Lepechinia schiedeana [26], Lippia alba [27], Xylopia americana [28], Hyptis umbrosa [29], Callistemon speciosus (sims) DC. [30], Swinglea glutinosa [31], Satureja viminea [32], and Lippia origanoides [33], with emphasis on the comparative study of extraction methods [34–40]. Table 1 summarizes the composition of several Lippia EOs, according to compound families. The knowledge of the chemical composition has been the basis for the interpretation of the results of bioactivity assays such as genotoxicity

#### Figure 8.

Fragment of GCxGC-HRMS-TOF chromatogram of ylang-ylang essential oil contaminated with plasticizer (phthalate) traces. m/z 149 is a base peak in alkyl phthalates' mass spectra.

the second column is polar, and vice versa. The modulation time, required for the transfer of a very small portion of eluent from the first column to the second, must be very short and similar but never longer than the elution time of the "slowest"

Ylang-ylang essential oil chromatogram (GC-MS) fragment. A. Chromatographic peak at tR = 30.76 min is highlighted. B. Mass spectrum corresponded to this peak, identified by the software as ethyl benzoate (Figure 6A); nevertheless, the peak is "contaminated" with other compounds; the presence of typical

sesquiterpene hydrocarbon ions (m/z 204, 189, 161,) is observed.

Figure 7.

Essential Oils - Oils of Nature

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#### Table 1.

Relative amounts of compound families in essential oils of various Lippia species grown in Colombia.

[41

section.

–43], antiviral [44] and antifungal [45

DOI: http://dx.doi.org/10.5772/intechopen.87199

[71], and antigenotoxic [41, 42] activities.

various chemotype extracts. Several uses of

source of bioactive substances.

–65], cytotoxic [30, 66

Study of Essential Oils Obtained from Tropical Plants Grown in Colombia

protozoarial activities [70, 71]. A few examples are highlighted in the following

4. Some biological activities of essential oils obtained in Colombia

EOs have been used in phytotherapy and folk medicine for their good odor and antibacterial, antifungal or insecticidal activities. Phenols, alcohols and aldehydes are EO components capable of crossing the cell wall, and in doing so, they alter its permeability and may cause leakage of macromolecules, loss of ions, structure disruption, and, eventually, cell death. This cytotoxicity enables EO applications against human pathogens or parasites and for the preservation of vegetal and marine products. Due to their large number of constituents, EOs affect several targets simultaneously, and this may be the reason for the lack of microorganism resistance development or adaptation. Besides cytotoxicity, the antioxidant properties of EOs are generally invoked as an indication of their potential benefits for human health. This is related to the notion that many diseases are due to high oxidative stress generated by diet, environmental contaminants, or work habits. However, the prooxidant properties of some EO components can play a protective role by promoting the removal of damaged cells. The mitochondria produce reactive oxygen species which can oxidize phenolic compounds (EO components) and give rise to reactive phenoxyl radicals which accelerate the general cell damage [72]. Genus Lippia (Verbenaceae family) has been the focus of attention of Colombian researchers (Figure 9). L. alba and L. origanoides EOs have appeared as the prominent representatives of this genus, after the evaluation of various Lippia genus EOs for antioxidant [33], antiviral [44], antimicrobial [69], antiprotozoal

Lippia origanoides Kunth (mountain oregano) is a good example of the aromatic plant biodiversity found in CENIVAM studies. It is an aromatic shrub found in the wild in northern South America and Central America. At least four different chemotypes have been distinguished according to differences in EO composition [34, 73]. Further research showed notorious differences in the compositions of the

L

medicine have been related to antimicrobial and analgesic activities due to phenylpropanoids and flavonoids found among its secondary metabolites. The detection of thymol and carvacrol as main EO constituents and pinocembrin, naringenin, quercetin, and luteolin in mg/g amounts in extracts of various

origanoides chemotypes supports the recognition of this species as a promising

the Lippia genus, preceded by L. alba. The useful bioactive properties found for L. origanoides oil have aroused interest in commercial applications such as food

important ingredient of various current chicken food commercial products. The most widely known sources of thymol and carvacrol are thyme (Thymus vulgaris

and oregano (Origanum vulgare), both of Eurasian origin. Thymol and carvacrol

19817:2017). Oregano EO contains around 22% thymol and 18% carvacrol. Thymol and carvacrol are major components in three L. origanoides chemotypes. Several projects conducted in CENIVAM have related the variations in EO composition with the steam distillation conditions, with the phenological stage, the agricultural

L

additive, preservative, or pest control agent, among others.

contents in thyme EO are in the range 37–55% and 0.5

conditions, and the post-harvest treatment.

133

. origanoides infusions in popular

. origanoides is the second most studied species of

L

L .

)

. origanoides oil is an

–5.5%, respectively (ISO

antioxidant capacity [60

–52] activities, insect repellence [53

–68], antituberculosis [69], and anti-

–59],

#### Study of Essential Oils Obtained from Tropical Plants Grown in Colombia DOI: http://dx.doi.org/10.5772/intechopen.87199

[41–43], antiviral [44] and antifungal [45–52] activities, insect repellence [53–59], antioxidant capacity [60–65], cytotoxic [30, 66–68], antituberculosis [69], and antiprotozoarial activities [70, 71]. A few examples are highlighted in the following section.
