Eduardo Valarezo

Chemical composition of essential oils of two species of the Lamiaceae family: Scutellaria volubilis and Lepechinia paniculata from Loja, Ecuador

Scutellaria volubilis and Lepechinia paniculata belong to the Lamiaceae family of species. They are used widely in traditional medicine in Ecuador. The physical properties and chemical composition of the essential oils from the aerial part of Scutellaria volubilis in its foliation – flowering stage and Lepechinia paniculata in its flowering phase have been studied after their hydrodistillation. The components of these essential oils were investigated by means of gas chromatography/mass spectrometry (GC/MS) and gas chromatography/flame ionization detection (GC/FID) techniques. Thirty-seven components were determined in the essential oil of S. volubilis. The principal constituents were found to be sesquiterpene hydrocarbons: germacrene D (20.4%), β-caryophyllene (17.5%), α-humulene (14.7%) and β-bisabolene (5.8%). Thirty-four components were identified in the essential oil of L. paniculata, the principal groups were sesquiterpene hydrocarbons such as aromadendrene (24.6%), viridiflorene (12.4%), β-selinene (7.4%) and valencene (6.7%). The monoterpene hydrocarbons were present in lower amounts as well as β-phellandrene (6.9%) and (7.7%). Oxygenated monoterpenes and sesquiterpenes contribute below 5% in both species. This is the first report on the chemical composition of this species.

Chemical composition, antifungal and antibacterial activity of the essential oil from Baccharis latifolia (Ruiz & Pav.) Pers. (Asteraceae) from Loja, Ecuador

The essential oil of aerial parts of Baccharis latifolia (asteraceae) growing wild in Ecuador was obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and GC/flame ionization detector (GC/FID). Twenty-nine compounds, representing 90.91% of the oil, were identified. The major components were limonene (33.72%), -phellandrene (10.32%), sabinene (10.28%), β-pinene (6.99%) and α-pinene (5.44%). The antifungal and antibacterial activities were determined by the broth microdilution method. The essential oil from B. latifolia exhibited activity only against Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (ATCC 28185).

Chemical composition and biological activity of the essential oil of Baccharis obtusifolia Kunth from Loja, Ecuador

The essential oil of aerial parts from Baccharis obtusifolia (Asteraceae) growing wild in Ecuador was obtained by hydrodistillation and examined by gas chromatography–mass spectrometry (GC–MS and GC–flame ionization detector (GC–FID) analysis. Thirty-one individual compounds were identified and constitute 96.1% of the total composition of the oil. The main constituents of the oil were limonene (28.3%), germacrene-D (9.8%), α-pinene (9.0%), β-pinene (8.2%), bicyclogermacrene (6.2%) and δ-cadinene (5.7%). The essential oil showed significant antibacterial and antifungal activity. Baccharis obtusifolia oil exhibited a moderate antibacterial effect against Klebsiella pneumoniae (ATCC 9997) and Enterococcus faecalis (ATCC 29212), and good antifungal activity against Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (ATCC 28185). In this study, the chemical composition and biological activity of the essential oil of B. obtusifolia (Asteraceae) are reported for the first time.

Composition of the Essential Oils of Artemisia sodiroi Hieron., Siparuna eggersii Hieron., Tagetes filifolia Lag. and Clinopodium nubigenum (Kunth) Kuntze from Loja Ecuador

Abstract The chemical composition of the essential oils from fresh leaves of four species (Artemisia sodiroi, Siparuna eggersii, Tagetes filifolia and Clinopodium nubigenum), grown wild in the southern Ecuador (province of Loja), was examined through the GC-MS analysis. In the essential oil of A. sodiroi, the oxygenated monoterpenes were the main group of components, especially sabinyl acetate (65.8 %), while the essential oil of S. eggersii was mainly composed by the oxygenated sesquiterpenes among which the epicurzerenone (29.9 %) was the most representative. Conversely, the aromatic hydrocarbons predominated in the oils of T. filifolia and C. nubigenum, with (E)-anethole (72.6 %) and carvacryl acetate (38.1 %) as the main components, respectively.

Acaricidal activity of essential oils of Bursera graveolens (Kunth) Triana & Planch and Schinus molle L. on unengorged larvae of cattle tick Rhipicephalus (Boophilus) microplus (Acari:Ixodidae)

Abstract The use of bio-derivatives as acaricides would be an effective and safe method of tick control. The acaricidal effect of essential oils obtained from Bursera graveolens (Burseraceae) and Schinus molle (Anacardiaceae), traditionally used by indigenous Ecuadorian medicine as insecticides, was tested on larvae of cattle tick Rhipicephalus (Boophilus) microplus. Essential oils were obtained from mature fruits by hydrodistillation and analyzed by gas chromatography. The acaricidal activity of essential oils against larvae was measured by larval package test with six concentrations of each essential oil. In total, sixteen compounds were identified in B. graveolens and twenty-one in S. molle essential oil. The mortalities of larvae in assays conducted with B. graveolens essential oil ranked from 35.43 to 100%; in S. molle from 5.58 to 100%. The obtained results show a clear and promising acaricidal effect of both essential oils over larvae of R. (B.) microplus.

Essential Oil Constituents of Mosses Species from Ecuador

Abstract Breutelia tomentosa (Sw. ex Brid.) A. Jaeger, Leptodontium viticulosoides (P. Beauv.) Wijk & Margad., Macromitrium perreflexum Steere, Campylopus richardii Brid., Rhacocarpus purpurascens (Brid.) Paris., and Thuidium peruvianum Mitt. essential oils were obtained by hydrodistillation. Using gas chromatography/flame ionization detector (GC/FID) and Gas chromatography/Mass spectrometry (GC/MS), a total of ninety four constituents were identified, representing for 80.5 93.8 % of the chemical composition. The major components were epizonarene (8.7 %) and α-selinene (6.7 %) in the oil of B. tomentosa, β-selinene (13.5 %) and α-selinene (10.5 %) in the oil of L. viticulosoides, selina-3,11-dien-6-α-ol (19.7 %) and curcuphenol (10.6 %) in the oil of M. perreflexum, epi-α-muurulol (15.1 %) and α-cadinol (12.5 %) in the oil of C. richardii. α-cadinol (36.8 %) and α-santalene (8.4 %) in the oil of R. purpurascens, and phytol (21.7 %) and valerenol (10.1 %) in the oil of T. peruvianum.

Biological Activity and Chemical Composition of the Essential Oil from Chromolaena laevigata (Lam.) R.M. King & H. Rob. (Asteraceae) from Loja, Ecuador

Abstract The chemical composition, antifungal and antibacterial activity of essential oils isolated by hydrodistillation from the aerial parts of Chromolaena laevigata (Asteraceae) growing wild in Ecuador, were evaluated. The chemical composition was analyzed by Gas chromatography/Mass spectrometry (GC-MS) and GC/Flame ionization detector (GC/FID). Twenty-five volatile components were identify in essential oils, corresponding to 96.13 % of the total oils. Essential oils was rich in laevigatin (46.84 %), germacrene D (15. 38 %), viridiflorol (11.37 %), bicyclogermacrene (4.14 %), limonene (4.94 %) and α-pinene (2.85 %). The antibacterial and antifungal activities were studied by the broth microdilution method. The antibacterial activity was tested against Gram-negative bacterial strains [Pseudomonas aeruginosa (ATCC 27853), Klebsiella pneumoniae (ATCC 9997), Proteus vulgaris (ATCC 8427), Escherichia coli (ATCC 25922) and Salmonella typhimurium (LT2)] and Gram-positive bacterial strains [Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 25923)] and antifungal activity was determined against Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (ATCC 28185). The essential oil from C. laevigata exhibited activity against Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (ATCC 28185).