Chemical Composition, in vitro Antibacterial Activity and Corrosion Inhibition of Essential Oil and Hydrolat Extract from Aerial Parts of Thymbra capitata (L.) Cav Harvested at Northern Morocco

Abstract

The present study aims to determine the chemical composition of essential oil (EO) and hydrolat extract (HE) of aerial parts of T. capitata (L.) Cav. from Morocco, to evaluate their antibacterial activity against four bacterial strains: Gram- (E. coli, Pr. Mirabilis) and Gram+ (B.subtilis, S. aureus), as well as their corrosion inhibiting powers against aluminum alloy (AA6063) in 3 % sodium chloride medium using two methods: the potentiodynamic polarization and impedance spectroscopy (EIS) measurements. The results showed that carvacrol (83.6 %) is the most dominant compound of T. capitata (L.) Cav EO followed by p-cymene (5.4 %) and α-humulene (3.5 %), while the T. capitata (L.) Cav HE almost consists of carvacrol (98.5 %) alongside some compounds in the form of traces. Both oils showed significant antibacterial activities against the bacterial strains tested. The T. capitata (L.) Cav EO has shown an inhibition efficiency of 74.52 % at a concentration of 2 g/L, while the T. capitata (L.) Cav HE has shown an inhibition efficiency of 85.55 % at the same concentration.Keys words: T. capitata (L.) Cav.; essential oil; hydrolat; potentiodynamic polarization; impedance spectroscopy; antibacterial activity; corrosion inhibition