Quality Analysis of Clove Essential Oil and In Silico Study of Metabolites on nAChR

Nicotine addiction occurs through its interaction with nicotinic acetylcholine receptors (nAChR), particularly the α4β2 subtype, in the central nervous system. Clove (Syzygium aromaticum) essential oil has the potential to serve as a natural therapy to overcome nicotine dependence. This study evaluated the quality of clove flower and leaf essential oils from Jatijejer Village and examined the activity of bioactive compounds on the α4β2 nAChR receptor in silico. Clove essential oil quality was analysed using Thin Layer Chromatography (TLC) and Gas Chromatography-Mass Spectrometry (GC-MS). The in silico study included drug-likeness prediction, binding energy analysis, and molecular interaction assessment. Steam distillation produced a pale yellow oil with the characteristic clove aroma, yielding 2.4% (flowers) and 1.4% (leaves). TLC revealed two active compound spots, while GC-MS analysis identified eugenol as the major component (23.44% in flowers and 26.1% in leaves), along with caryophyllene and humulene as secondary components. The in silico analysis showed several compounds with binding energies equal to or lower than nicotine (-6 kcal/mol); eugenol (-5.6 kcal/mol), caryophyllene (-5.7 kcal/mol), and humulene (-5.8 kcal/mol) exhibited slightly higher energies but maintained good binding affinity. Amino acid interaction analysis indicated that 2-nonanol, 3-allyl-6-methoxyphenol, phenol, 2-methoxy-4-(2-propenyl)-acetate, and trans-isoeugenol shared the highest similarity with nicotine (83.33%), while 2-nonanol and linalool showed high similarity with varenicline (86.36%). All 23 compounds met Veber’s Rule, and 20 compounds were predicted to cross the blood–brain barrier (BBB). Clove essential oil from Jatijejer demonstrates promising potential to be developed further as a natural therapy for overcoming nicotine addiction.