**2. Myrtaceae family**

80% of the population in developing countries use them for their primary health-care needs, either because of cultural tradition or because there are no other options, due to the high cost

The diverse nature of chemical compounds produced by species of the family Myrtaceae has allowed to locate it as one of the families of greater medicinal use, since some of its species are used to treat respiratory affections [2–5], to strengthen the gums, pains of tooth [3], gastrointestinal disorders [4, 6], skin conditions and snake bites [4–6], for rheumatic or muscular pain, neuralgia, migraine, nervous system disorders, fevers, diseases of the urinary system, diabetes [2, 4, 6], help in job of childbirth [7], and from the economic point of view by their

Genus *Pimenta*, one of the representatives of this family, comprises 21 species including several varieties, is typical of tropical America [9, 10], is considered of medicinal and economic interest, and is rich in a structural variety of volatile substances such as monoterpenes, sesquiterpenes, and phenylpropenes (present in the essential oils), can generate from fresh leaves, a

Essential oils derived from plants, obtained by hydrodistillation, steam distillation, or by extraction with organic solvents, are complex mixture that may contain between 20 and 100 volatile substances of low-molecular weight belonging to different chemical classes, which are presented as liposoluble liquids at room temperature, generally colorless or pale yellow, light, hydrophobic (soluble in alcohol, non-polar or weakly polar solvents, waxes, and oils), and easily oxidizable by exposure to air, light, and heat [13], and they can be biosynthesized in different parts of the plant anatomy (in the leaves, in the flowers, in the fruits, in the pericarp of the fruit, in the seeds, in the bark, and in the rhizomes, whether they are stored in oil

Interest in essential oils in recent years is based on the versatility of its use in different industrial areas (pharmaceutical, food, health, cosmetics, and perfumery), not only on the possibility of obtaining aromatic compounds (pleasant odor) but in its application as antioxidants, food preservatives, and medicines, and its application as protectors of crops and plants, incorporating them into the packaging material of the products, being less toxic than the synthetic antioxidants of greater use [14–16] or incorporated in dermocosmetic formulations aimed at the treatment and prevention of skin diseases mediated by oxidative stress [15, 17]. This is the case of essential oil obtained from *Pimenta racemosa* var. *racemosa*, which, for its aroma and antioxidant and antimicrobial activity, has been incorporated in perfumes, creams, formulations of aftershave lotions, soaps and hair treatments, as antifungal treatment for aquarium waters and flavorings of foods and products of confectionery, making it a very valuable ingre-

Taking into account that essential oils represent a therapeutic alternative in natural products against several pathogens that threaten public health and individual health of patients, it would be interesting to establish for genus *Pimenta*, if the chemical composition of its volatile essences has among their major components chemotypes that can classify the oils of the

of medicines for these populations [1].

22 Potential of Essential Oils

wood and as a producer of spices and essential oils [8].

content of volatile essences between 1 and 5% [11, 12].

glands, glandular hairs, or dissolved in resins) [13, 14].

dient for the cosmetic, pharmaceutical, and food industry [14–25].

Myrtaceae Juss., the name derived from the genus *Myrtus communis* [26], which comes from the Mediterranean region [27], is considered within the angiosperms as one of the largest families in the world, occupying the eighth place of flowering plants and of considerable importance in the ecological and economic area (by its production of essential oils), corresponds to the subclass Rosidae and to the order Myrtales [28]; it contains more than 5500 species separated by taxonomists in two subfamilies, Psiloxyloideae and Myrtoideae, 17 tribes and approximately 150 genera [9, 29–31]; its species are often difficult to identify and classify, so a high probability of plants that still remain undescribed is estimated [32].

The species that belong to this family have a primarily tropical and subtropical distribution, with a greater diversity in the southern hemisphere, dispersed mainly in regions of South America, Central America, Asia, east and southwest of Australia, and with a low representation in Africa [8, 9, 16, 33], having mostly shrubs and trees predominantly woody, ericoids, with evergreen leaves. Venezuela has 20 native genera, five genera introduced with several species in cultivation [34], and about 246 species, of which 34 species (+2 varieties) are endemic to the country [35, 36].

This family is very old. It is believed that it originated in the Cretaceous period [31], diversifying widely over time from the most primitive forms of rainy and humid forests to specialized forms in semi-arid, very dry regions, highly influenced by seasonal changes [37]; its diverse nature of chemical compounds produced by species of the family Myrtaceae has allowed to locate it as one of the families of source of substances with pharmacological activities [2–13], as a producer of woods, spices, and essential oils [9].
