Chemical Profiling of Stachys cretica subsp. anatolica Rech. f. (Endemic) Essential Oils and their Methanol Extracts with Evaluation as Enzyme Inhibitors, Antioxidant, and Antimicrobial Agents

Abstract

Enzyme inhibition activities, phenolic compounds, antioxidant activities, bioactive compounds, antimicrobial activities, and chemical components of essential oil and methanol extracts obtained from the aerial parts of S. cretica subsp. anatolica were investigated. The main phenolic compounds of aerial parts were catechin, oleuropein, and epicatechin. The determined enzyme inhibitor activities highlight the potential of S. cretica subsp. anatolica as a source of bioactive compounds, particularly for carbonic anhydrase and cholinesterase inhibition. The essential oil and methanol extract exhibited remarkable activities against CA-II, AChE, and BChE, although they were less potent than standard inhibitors. The essential oils generally showed stronger antimicrobial activity compared to the 30% methanol extracts across most bacterial and fungal strains, as evidenced by minimum lethal concentration (MLC) and lower minimum inhibitory concentration (MIC) values and larger inhibition zones. Chloramphenicol used alone exhibited the highest antimicrobial efficacy, with the lowest MIC and MLC values and the largest inhibition zones. The essential oils of S. cretica subsp. anatolica were determined as esters, oxygenated sesquiterpenes, and aldehydes in aerial parts. The main components were found to be hexahydrofarnesyl acetone in the aerial parts.