Anticholinesterases activity of Murraya koenigii (L.) Spreng. and Murraya paniculata (L.) Jacq. essential oils with GC/MS analysis and molecular docking

GC/MS analysis of Murraya koenigii (L.) Spreng. and Murraya paniculata (L.) Jacq. leaves revealed the identification of 73 components, with an evident greater contribution of monoterpenes hydrocarbons to their total volatiles. α-Pinene (37.5%) and β-caryophyllene (27.4%) were the most abundant compounds in M. koenigii leaves and β-phellandrene (40.7%) in M. paniculata leaves, using headspace. β-Phellandrene (33.7%) was the major constituent by M. koenigii leaves where germacrene D (23.8%), and δ-elemene (22.0%) were predominant in M. paniculata leaves, using steam distillation. M. koenigii leaves oil showed quite remarkable cholinesterase inhibitory activity, where oil of M. paniculata leaves showed strong inhibitory activity against AChE (IC₅₀=13.2 ± 0.9 µg/mL) and BChE (IC₅₀=5.1 ± 0.3 µg/mL). Germacrene D, α-zingiberene, and δ-elemene showed higher affinity to BChE than AChE as revealed from docking scores (S = −5.65 to −6.03 Kcal/mol) for BChE and (S = −5.56 to −6.25 Kcal/mol) for AChE.