Composition and Insecticidal Activity of Essential Oil of Bacopa caroliniana and Interactive Effects of Individual Compounds on the Activity

Abstract

Bacopa caroliniana (BC) is a perennial creeping herb and popular aquarium plant. This plant is easily cultivated; consequently, it has the potential to be a raw material which is readily available for mass production if it contains useful bioactive substances. The information about the functionality of this plant has been very limited. Therefore, the aims of this research were to analyze the composition of the essential oil (EO) of BC and to study its insecticidal effect on rice weevils. Moreover, the interactive effects of active compounds of the EO on this activity were also investigated. A total of 18 volatile compounds was identified, accounting for ca. 94% of the BC-EO in terms of quantity. Of them, α-terpinolene was the largest compound. The impact of individual volatile compounds on the inhibition of acetylcholine esterase and insecticidal activity were determined. α-Terpinolene exhibited the highest activity on these assays. Both additive and synergistic effects existed in terms of the insecticidal activity. Many compounds found in the BC-EO are widely present in other EOs. Thus, the information obtained from this study is useful for EO-related research, applications in selecting EOs or in seeking the best combination of EOs or individual compounds to achieve efficient insecticidal effects.

Evaluation of the Toxicity of Satureja intermedia C. A. Mey Essential Oil to Storage and Greenhouse Insect Pests and a Predator Ladybird

“…The insecticidal properties of several terpenes, especially monoterpene hydrocarbons and monoterpenoids, which accounted for 88.9% of the S. intermedia essential oil in the present study, have been documented in recent investigations. For example, insecticidal activities of p -cymene, α-pinene, γ-terpinene, 1,8-cineole, and limonene have been demonstrated against several detrimental insect pests [ 46 , 47 , 48 , 49 , 50 ]. Previous studies have also indicated that the monoterpenoids thymol and carvacrol had significant toxicity against insect pests [ 46 , 51 , 52 ].…”

Composition of the Essential Oil and Insecticidal Activity of Launaea taraxacifolia (Willd.) Amin ex C. Jeffrey Growing in Nigeria

“…Sabinene, on the other hand, demonstrated weaker insecticidal activity against S. oryzae (24-h LC 50 463 μL/L) [ 44 ]. Interestingly, the S. oryzae fumigant insecticidal activities of limonene and sabinene parallel the acetylcholinesterase (AChE) inhibitory activities; AChE IC 50 = 9.57 μL/mL and 85.03 μL/mL, respectively, for limonene and sabinene [ 48 ]. Furthermore, the binary combination of limonene + sabinene showed synergistic AChE inhibition [ 48 ].…”

“…Interestingly, the S. oryzae fumigant insecticidal activities of limonene and sabinene parallel the acetylcholinesterase (AChE) inhibitory activities; AChE IC 50 = 9.57 μL/mL and 85.03 μL/mL, respectively, for limonene and sabinene [ 48 ]. Furthermore, the binary combination of limonene + sabinene showed synergistic AChE inhibition [ 48 ]. The insecticidal activity of the L. taraxacifolia essential oil could be attributed to those known major components and the resulting synergistic action of the monoterpene hydrocarbons limonene (48.8%) and sabinene (18.8%).…”

Effects of Zanthoxylum caribaeum essential oil against cotton bug Dysdercus peruvianus

“…Most studies have been used whole EOs or only their major compounds for the investigation (Senthil et al, 2006) and few studies have worked on the interactive effects of the several oil components (Park et al, 2017). Thus, the information about the effects of interaction among individual compounds on the functionality of EOs has been limited and are needed to clarify possible applications in selecting EOs or in seeking the best combination of EOs or individual compounds to achieve efficient insecticidal effects since essential oils may be more efficacious than the pure compounds derived from them due to synergism or joint action of active compounds with different modes of action (Liu et al, 2020).…”