Planta Med 2014; 80 - P1L59
DOI: 10.1055/s-0034-1394716

Chemical composition and vapour phase antimicrobial activity from the essential oil of Hesperozygis myrtoides (St.Hil. ex Benth.) Epling (Lamiaceae)

MAA Pereira 1, I Cordeiro 2, S Nicolau 2, TM Kaneko 1, PRH Moreno 1, 3
  • 1Prog. Pós Grad. Fármacos e Medicamentos, Fac. Ciências Farmacêuticas – USP. Av. professor Lineu Prestes, 580 – CEP 05434 – 070, São Paulo (SP), Brazil
  • 2Instituto de Botânica SMA/SP, Av. Miguel Estefano, 3496, CEP 04301 – 902, São Paulo (SP), Brazil
  • 3Lab.de Química de Produtos Naturais, Inst. de Química, USP, Cx. Postal: 26077 – CEP 05599 – 970, São Paulo (SP), Brazil

Essential oil (EO) vapours have been used for their antimicrobial properties since ancient times. In the literature, this activity is commonly tested in the liquid phase, although currently the vapour phase activity has gained interest. Hesperozygis myrtoides (St.Hil. ex Benth.) Epling is a small aromatic bush that is used for treating respiratory diseases [1]. Thus, the aim of the present work was to analyse the H.myrtoides EO composition and the antimicrobial activity of its vapours from plants collected in Campos do Jordão (São Paulo, Brazil). The EO was obtained by hydrodistillation for 4h, and the component identification was performed by GC/MS [2]. The antimicrobial activity of the EO vapours was evaluated by the inverted plate method [3] against Staphylococcus aureus (ATCC 25923) and Candida albicans (ATCC 10231), using formaldehyde as positive control. The average EO yield was 1.7% (w/w), presenting as major components pulegone (31%), isomenthone (16%), neo-isomenthyl acetate (12%), neo-isomenthol (10%) and menthone (6%). The EO vapours were able to inhibit the growth of S. aureus and C. albicans, with Minimum Inhibitory Concentrations (MIC) of 392 µg/L and 833 µg/L, respectively. The positive control, for the respective microorganisms, presented MICs of 22.4 µg/L and 820 µg/L. These results indicated that the EO vapours were as active as formaldehyde against the yeast C. albicans. Although the lower activity against the bacterium, the H.myrtoides EO can be considered promising for further studies, once in screening studies extracts with MIC values lower than 100 µg/mL are considered good candidates for developing new antimicrobial agents [4]. The EO vapours have the advantage as sanitizers because they can treat large areas without requiring direct application on surfaces, which is suitable for the use as room disinfectants and air decontaminants even in inhabited areas due to their lower toxicity compared to that of formaldehyde.

Keywords: essential oil, vapour phase, antimicrobial activity, Hesperozygis myrtoides, pulegone

References:

1. Martin, MG, et al. Chemical Composition and Antimicrobial Activities of the Essential Oils from Ocimum selloi and Hesperozygis myrtoides. Nat Prod Commun 2011; 6: 1027 – 1030.

2. Moreno PRH, et al. Chemical Composition and Antimicrobial Activity of the Essential Oil from Croton heterocalyx Baill. (Euphorbiaceae s.s.) Leaves. J Essent Oil Res 2009; 21: 190 – 192.

3.Kloucek P, et al. Fast screening method for assessment of antimicrobial activity of essential oils in vapor phase. Food Res Int 2012; 47: 161 – 165.

4. Moreno, PRH, et al. Native Brazilian Plants Against Nosocomial Infections: A Critical Review on their Potential and the Antimicrobial Methodology. Curr Top Med Chem 2013; 13: 3040 – 3078.