ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS, cilt.93, sa.3, 2021 (SCI-Expanded)
Stachys species belonging to Lamiaceae family have been used for medicinal purposes since ancient times. The aim of the present study was to investigate the chemical compositions and antibacterial, anti-tyrosinase activities of the essential oil of Stachys macrostachya. The essential oil was prepared by hydrodistillation method using a Clevenger-type apparatus and chemical composition was determined by gas chromatography (GC). The antibacterial activity of essential oil was performed by the disc diffusion and microdilution broth method against five Gram-positive and two Gram-negative bacteria. The tyrosinase inhibitory activity was evaluated by minor modifications of Masuda's method. According to the results of GC analyses, twenty-three compounds were identified representing 91.9% of the total volatile composition. The main compounds were germacrene D (12.2%), globulol (10.9%), alpha-pinene (9.7%), and valencene (7.6%). The present study showed that the tested essential oil of S. macrostachya exhibited antibacterial activity against Acinetobacter baumannii (MIC 62.50 mu g/mL) and tyrosinase inhibition activity (IC50 22.86 +/- 0.82 mu g/mL). These results suggest that the essential oil could be exploited as a potential source of natural antimicrobial agents of this bacterium as well as tyrosinase inhibitors.