Essential oil of Minthostachys mollis[HBK] Griseb. leaves from Ecuador: Extraction, chemical composition, antioxidant capacity and antimicrobial activity

Abstract

The aim of this study was to optimize by response surface design, the extraction of the leafessential oil (EO) from Minthostachys mollis [HBK] Griseb., grown in Ecuador, using steam distillation. The factors used were extraction time (XTIE) of 60, 105 and 150 min and plant material/water ratio (XRMA) of 1:3, 1:4 and 1:5. The optimal combination was reached with XRMA 1:5 and XTIE 150 min, obtaining a process yield of 0.67%. The chemical composition of the EO analyzed by GC-MS was determined, where the main compounds were carvacryl acetate (44.01%), carvacrol (16.51%) and menthone (8.20%). The antioxidant capacity of EO was evaluated using the FRAP and ABTS methodologies, with an IC50243.21 μmol Fe2+/g and 0.12 mg/mL, respectively. In addition, the antimicrobial activity of EO was found against Pseudomonas aeruginosa, Salmonella enterica, Escherichia coliand Staphylococcus aureus.