ABSTRACT The eucalyptus essential oil has been used in the natural medicine and it has been investigated the medicinal properties of these species that include a wide range of biological activities. The composition of an essential oil can be affected by several factors, such as genetic, ontogenic, morphogenetic and environmental factors. The present work investigated the chemical composition and antibacterial activity of the leaf essential oil of Eucalyptus globulus Labill. plants, which grow in Moyancón and Chorocópte regions (1347 and 3191 m height above sea level, respectively) in the canton Cañar, Ecuador. The essential oils were isolated by means of hydrodistillation during two hours and analyzed by gas chromatography coupled to flame ionization and mass selective detectors. The essential oil yields of leaves from Moyancón and Chorocópte regions were 0.17 % and 0.15 % (v/m), respectively. A total of 99 volatile compounds were identified and quantified, where 1,8-cineol and (-pinene were the major compounds. No significant differences in the composition were found by effect of the growth region. The essential oil from Moyancón region showed moderate antibacterial activity against Staphylococus aureus, Streptococus pyogenes and Eschericha coli.

RESUMEN El aceite esencial de eucalipto se ha usado en la medicina natural y se ha investigado las propiedades medicinales de estas especies, que incluyen una amplia gama de actividades biológicas. La composición de un aceite esencial puede estar afectada por varios factores, tales como variación fisiológica, condiciones ambientales, variaciones geográficas, así como factores genéticos y evolutivos. En el presente trabajo se investigó la composición química y actividad antibacteriana del aceite esencial de hojas de Eucalyptus globulus Labill. que crece en las regiones de Moyancón y Chorocópte (1347 y 3191 metros sobre el nivel del mar, respectivamente) en el cantón Cañar, Ecuador. Los aceites esenciales fueron aislados mediante hidrodestilación durante dos horas y analizados por cromatografía de gases con detectores de llama de hidrógeno y selectivo de masas. Los rendimientos de aceite esencial para las regiones de Moyancón y Chorocópte fueron 0.17 % y 0.15 % (v/m), respectivamente. Se identificaron y cuantificaron 99 compuestos volátiles, donde predominaron el 1,8-cineol y α-pineno. No se encontraron diferencias significativas en la composición por efecto de la región de crecimiento. El aceite esencial de la región de Moyancón mostró actividad antibacteriana moderada contra Staphylococus aureus, Streptococus pyogenes y Eschericha coli.

The antiviral activity of extracts obtained from Ageratina havanensis (Kunth) R.M.King & H.Rob., Asteraceae, against rabbit vesivirus (RaV) (Caliciviridae) and human herpes simplex viruses type 1 and 2 (HSV-1, HSV-2) (Herpesviridae) were analyzed, and the main metabolites from the most active extract were isolated and characterized. The antiviral properties were investigated by measuring the inhibition of viral-induced cytopathic effect in Vero cells. The strongest inhibitory effects were found for ethyl acetate extract from leaves (SI=5 for RaV and SI=5.4 for HSV-1). The crude ethyl acetate extract was further fractionated by chromatographic methods and the structures of isolated compounds were established through comprehensive spectroscopic analyses, including IR, 2D NMR and MS. Four flavonoids were identified: 5,4'-dihydroxy-7-methoxyflavanone (sakuranetin), 3,5,4'-trihydroxy-7-methoxyflavanone (7-methoxyaromadendrin), 4'-O-β-D-glucosyl-5,3'-dihydroxy-7-methoxyflavanone (4'-O-β-D-glucosyl-7-methoxy-eriodictyol) and 4'-O-β-D-glucosyl-5-hydroxy-7-methoxyflavanone (4'-O-β-D-glucosylsakuranetin). This is the first report on antiviral activity for Ageratina havanensis.

Interest in natural products as a source for innovation in drug discovery and agrochemicals is still growing worldwide. Natural products, whose immense diversity has been appreciated for many years, may become in a rich source of novel chemical structures. Our country is a rich source of both biological and chemical diversity which may be useful as a source of novel chemical structures. Even when natural products have been used as medicinal agents for many years in Cuba, their use as agrochemicals are still limited. Thus, the present review focuses on recent advances in the studies on natural products performed by the "Centro de Estudios de Productos Naturales, CEPN" during the past ten years, highlighting on those with potential use as biomedical and agrochemicals. 15 plant species were studied; Agave brittoniana Trel. Subsp. brachypus A Álvarez de Zayas (Agavaceae); Juniperus barbadensis L. var. Lucayana (Britt.) RP Adams (Cupressaceae); Melia azedarach Linn. (Meliaceae); Tectona grandis Linn. f. (Lamiaceae); Lantana camara Linn. (Verbenaceae); Lantana trifolia Cham. (Verbenaceae); Citrus sinensis (Linn.) Osbeck cv Valencia (Rutaceae); Maytenus buxifolia (A Rich) Griseb (Celastraceae); Maytenus elaeodendroides Griseb (Celastraceae); Maytenus urquiolae B Mory (Celastraceae); Solanum americanum W. Mill (Solanaceae); Thalassia testudinum Kon. (Hydrocharitaceae); Sesbania rostrata Bremek & Oberm (Fabaceae); Pluchea carolinensis G Don (Asteraceae) and Ageratina havanensis (HB & K) RM King & Robinson (Asteraceae). By means of a bio-guided fractionation, isolated structures as well as semi-purified fractions were assayed as antioxidant, antiparasitic, antibiotic, insecticides, antifungal, and skin regenerating and healing effects. The strategy employed allows us to discover novel secondary metabolites with potential for industrial development as pharmaceuticals and/or agrochemicals. Besides, in addition to the goal of discovering new bioactive agents, the presence of unique bioactive compounds notably contribute to increase the knowledge of plant species in Cuba.

Se llevó a cabo un experimento para evaluar, mediante el análisis de componentes principales (ACP) y de clasificación automática (ACA), las variaciones de la composición química e indicadores de valor nutritivo en el follaje de diecinueve accesiones de Leucaena leucocephala Lam. de Wit establecidas en Matanzas, Cuba. Se determinó la composición bromatológica, los niveles de metabolitos secundarios y la degradabilidad ruminal in situ de la MS, PC y FDN. Mediante el ACP se detectó una variabilidad discreta para los primeros tres componentes(48,87%). Los indicadores que explicaron mejor las variaciones entre las accesiones fueron los niveles de MS, PC, PV, FDN, FDA, FC, LDA, celulosa, Ca, cenizas, taninos condensados (TC) y degradabilidad de la MS. Sin embargo, la concentración de P, K, polifenoles totales, taninos precipitantes, fitatos, mimosina y la degradabilidad ruminal de la PC y FDN no constituyeron variables fidedignas para comparar las accesiones evaluadas en las condiciones experimentales. Mediante el ACA se identificaron cinco grupos con características distintivas entre sí. Aunque todas las accesiones presentaron buena composición química y valor nutritivo las accesiones de mejores resultados fueron CIAT-9438, CIAT-8069, CIAT-7985, CIAT-9119, CIAT-9993, CIAT-7929 y CIAT-937. Solamente los TC constituyen metabolitos secundarios con importancia comparativa.

An experiment was carried out in order to evaluate, using the main components (ACP) and automatic classification analysis (ACA), the chemical composition and nutritional value variations of nineteen accessions of Leucaena leucocephala Lam. de Wit foliage in Matanzas, Cuba. Bromatological composition, secondary metabolites level and in situ ruminal degradabilidad (DM, CP and NDF) were determined. A discreet variability for the first three components (48,87 %) were detected. The DM, CP, TP, NDF, ADF, CF, ADL, cellulose, Ca, ashes and condensed tannins (CT) levels and DM ruminal degradability explained the variability among the evaluate accessions. However, under experimental conditions the P, K, total polyphenols, precipitant tannins, phytates and mimosine concentration, and CP and NDF ruminal degradability constitute marginal variables to compare the accessions. Using the ACA in dependence of the nutritional profile five groups with distinctive characteristic to each other were identified. The studied accessions differ fundamentally for their proximal composition and the CIAT-9438, CIAT-8069, CIAT-7985, CIAT-9119, CIAT-9993, CIAT-7929 y CIAT-937 accessions showed the best results. Only the CT constitutes the group of secondary metabolites with comparative importance.