Chemical Compositions and Antimicrobial and Mosquito Larvicidal Activities of the Leaf Essential Oils of Goniothalamus yunnanensis W.T.Wang and G. touranensis Ast: Experimental and In Silico Approaches

Abstract

The current research describes a phytochemical analysis and antimicrobial activity of essential oils extracted from the leaves of two Vietnamese Annonaceae species Goniothalamus yunnanensis W.T.Wang and G. touranensis Ast. By the GC‐FID/MS (gas chromatography‐flame ionization detection/mass spectrometry) analyses, sesquiterpene hydrocarbons accounted for the highest percentage of 68.22% in G. yunnanensis leaf essential oil with bicyclogermacrene (31.03%) and (E)‐caryophyllene (21.12%) being the main compounds. G. touranensis leaf essential oil was dominated by monoterpene hydrocarbons (57.08%) with p‐cymene (19.95%) and α‐pinene (16.82%) being the major compounds. Two oil samples showed strong antibacterial effects on the Gram‐positive bacteria Enterococcus faecalis ATCC51299, Staphylococcus aureus ATCC29213, and Bacillus cereus ATCC11778 with the MIC values of 16‐64 µg/mL. They also inhibited the growth of the yeast Candida albicans ATCC 60193 with the same MIC value of 128 µg/mL. Both two oil samples showed strong mosquito larvicidal activity against four‐instar larvae of Aedes aegypti and Ae. albopictus with the 24‐h LC50 values of 16.75‐27.60 µg/mL and 24‐h LC90 values of 24.31‐46.18 µg/mL. Docking results indicated that bicyclogermacrene and p‐cymene exhibited the highest ΔG (binding affinity) values of –8.208 and –6.799 kcal/mol with the olfactory binding proteins (OBPs) of Ae. aegypti and Ae. albopictus, respectively.