Chemical composition and antimicrobial activity of the essential oil from the leaves and flowers of Aloysia gratissima

Abstract

Volatile oils from leaves and flowers of Aloysia gratissima were investigated for their chemical composition and antimicrobial activity against the bacteria Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae and the Candida albicans yeast. The minimum inhibitory concentrations (MIC) of the oils were determined by the micro-dilution method, while the chemical composition was determined by GC-MS (gas chromatography mass spectrometry). The fresh leaves and inflorescence were subjected to hydrodistillation for 120 min using a Clevenger-type apparatus, and the essential oil was tested against microorganisms. High concentrations of sesquiterpenes were observed for the inflorescence, and monoterpenes were observed for the leaves. The main compounds of the inflorescence essential oil were E-caryophyllene, germacrene B, guaiol and bulnesol, while in the leaves the main compounds were trans-pinocamphone, trans-pinocarveyl acetate, and guaiol. The essential oil from the leaves showed an effect against P. aeruginosa and S. pneumonia, and the essential oil of the inflorescence showed an effect against P. aeruginosa, S. pneumonia, and Candida albicans.

Thein vitroantileishmanial activity of essential oil fromAloysia gratissimaand guaiol, its major sesquiterpene againstLeishmania amazonensis

“…Additionally, trans-caryophyllene and its oxide (7% total) were also identified in the oil composition. A similar sesquiterpene constitution in the oil of A. gratissima leaves and flowers was recently described (Santos et al 2013), although a distinct monoterpene composition was characterized. Other studies identified similar compounds as well as different proportions of guaiol in A. gratissima leaf oil such as 2·6% (Santos et al 2013), 11·5% (Santos et al 2015) and 12·5% of guaiol (Trovati et al 2009).…”

“…A similar sesquiterpene constitution in the oil of A. gratissima leaves and flowers was recently described (Santos et al 2013), although a distinct monoterpene composition was characterized. Other studies identified similar compounds as well as different proportions of guaiol in A. gratissima leaf oil such as 2·6% (Santos et al 2013), 11·5% (Santos et al 2015) and 12·5% of guaiol (Trovati et al 2009). These differences can be attributed to diverse environmental conditions, including the type of soil, climate, plant age and the part of the plant used to obtain the oil (Velasco-Negueruela and Pérez-Alonso, 1993).…”

“…Microbicidal effects of AgEO have been demonstrated for bacteria, fungi and viruses (Dellacasa et al 2003; Garcia et al 2003; Santos et al 2013). AgEO obtained from leaves and flowers was bactericidal and fungicidal, although EO obtained from flowers was more effective against the Gram-negative P. aeruginosa , the Gram-positive S. pneumonia and the yeast C. albicans.…”

“…AgEO obtained from leaves and flowers was bactericidal and fungicidal, although EO obtained from flowers was more effective against the Gram-negative P. aeruginosa , the Gram-positive S. pneumonia and the yeast C. albicans. These differences may be attributed to the higher amount of sesquiterpenes present in the flower EO (Santos et al 2013). It has also been reported that AgEO is able to inhibit the growth of Junin virus and inactivate herpes simplex virus type 1 (Garcia et al 2003).…”

“…Steudel) species, known as 'Brazil lavender', are commonly used in the Brazilian folk medicine for the treatment of digestive and respiratory diseases, and their flowers are employed in perfume compositions. Some reports have characterized the microbicidal effect of A. gratissima against bacteria, yeast and virus (Dellacasa et al 2003;Garcia et al 2003;Santos et al 2013Santos et al , 2015. Guaiol is a sesquiterpene alcohol found in many medicinal plants, which have been proved to possess antibacterial and antitumor activities (Choudhary et al 2007;Yang et al 2016).…”