Nature gives us a large number of compounds with interesting biological properties, within them we have essential oils, which are an important source of new bioactive molecules, which can replace synthetic chemicals, since they are friendly to the environment and they are less toxic. Currently there are more than 20.000 publications in which essential oils are related to some biological activity, according to the search made in different databases until January 2018. This confirms the wide utility of essential oils as the main source of bioactive metabolites, which can be used in different areas of our life.

ResumenSe evaluó la composición química y la actividad antibacteriana del aceite esencial Minthostachys mollis cultivado en el departamento de Norte de Santander, Colombia. El aceite esencial fue obtenido por hidrodestilación convencional, a partir de las hojas; se determinó densidad relativa a 20°C, índice de refracción; solubilidad de los aceites esenciales en etanol (70% v/v) y rotación óptica. La composición química se evaluó mediante cromatografía de gases/espectrómetro de masa. La actividad se realizó sobre tres bacterias: Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228 y Escherichia coli ATCC 25922. Para determinar la sensibilidad antibacteriana y la concentración mínima inhibitoria, los aceites se diluyeron hasta la concentración deseada (1000-50 µg/mL) empleando el método de microdilución en caldo, y se empleó el lector de microplacas para la cuantificación del crecimiento bacteriano. El rendimiento fue de 0,6%. Los resultados de la prueba de sensibilidad mostraron que las bacterias fueron sensibles al aceite esencial de Minthostachys mollis; además, este aceite presentó un elevado contenido de monoterpenos oxigenados con reconocida actividad antibacteriana, como son el carvacrol y el timol. En función de los resultados obtenidos, concluimos que la especie vegetal evaluada es promisoria para el control del componente bacteriano.Palabras clave: Muña, aceite esencial, actividad antibacteriana.

Essential oils (EO) are complex mixtures of biosynthesized chemicals basically by plants, which provide them their characteristic aroma. Many have biologically recognized activities as antioxidants and anti-inflammatory among others, and many of them are employed as cosmetic actives. Very often, these properties are not fully exploited because of their high volatility and tendency to oxidize, so it is necessary to attach them to a conveyor to provide them adequate stabilization and lifetime. One of the best alternatives to carry out this is microencapsulation, for which natural biopolymers can be used, such as the starches. Therefore, it used EO of thyme, cinnamon, and clove, which were obtained by conventional and assisted hydrodistillation by microwave radiation from the plant material. The chemical composition was evaluated by gas chromatography/mass spectrometry (GC/MS). The radical scavenging ability was determined by antiradical activity techniques including DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-(3-ethylthiazoline-benzenesulfonic acid-6)), and the ORAC method was used for determining the antioxidant capacity. Also, starches of yam (D. rotundata), sweet potato (I. batatas), corn (Z. mays), and cassava (M. esculenta) were used, which were subjected to hydrolysis and lipophilization processes using dodecenyl succinic anhydride (DDSA); this chemical process achieves a significant increase in emulsifier capacity (surfactant) compared to its native state; that of cassava was the most promising starch which was used as an EO microencapsulating agent. Finally, from the EO microcapsules, an emulgel-type cosmetic was designed which maintained its antioxidant activity. The results of this work contribute to the development of stable and functional cosmetic formulations of essential oils, emphasizing that the extraction of EO by assisted microwave radiation hydrodistillation is considered a fast, efficient, green, and relatively economical method compared to conventional hydrodistillation.