Essential oil of endemic Centaurea paphlagonica: chemical composition, insecticidal, enzyme inhibitory activities and molecular docking approach

Abstract

The key objective of this study was to determine the chemical composition, insecticidal and butyrylcholinesterase (BChE) inhibitory activities of crude essential oils (CEO) extracted from the stem-leaf parts of the endemic Centaurea paphlagonica plant via steam distillation, as well as its chromatography-based fractions for the first time. According to GC-MS analysis, eighty-five compounds were identified representing 98.49% of the total essential oil. beta-Eudesmol (15.17%), phytol (8.69%), and spathulenol (8.03%) were determined as the main components. The CEO demonstrated a remarkably insecticidal activity against S. granarius and R. dominica insects, ranging from 98.35% to 100%, while achieving a 50% against T. confusum at a 10% concentration. The silica gel-based fractionation of CEO resulted in four qualitatively different fractions (CEO-F1 to F4). The CEO-F2, predominantly comprised of beta-eudesmol and spathulenol, exhibited superior activity compared to CEO across all tested insects. In addition, the inhibitory activity of BChE, which causes death in insects by altering nervous system activities, was assessed. BChE inhibition activity of CEO and CEO-F2 was determined as IC50=346.57 mu g/mL and 96.02 mu g/mL, respectively, supporting the insecticidal activity tests and molecular docking studies. The volatile oil obtained from C. paphlagonica can be considered a potential natural source to combat storage product pests, with its significant natural volatile compounds.