Medium-Chain Fatty Acids from Eugenia winzerlingii Leaves Causing Insect Settling Deterrent, Nematicidal, and Phytotoxic Effects

Abstract

Eugenia winzerlingii (Myrtaceae) is an endemic plant from the Yucatan peninsula. Its organic extracts and fractions from leaves have been tested on two phloem-feeding insects, Bemisia tabaci and Myzus persicae, on two plant parasitic nematodes, Meloidogyne incognita and Meloidogyne javanica, and phytotoxicity on Lolium perenne and Solanum lycopersicum. Results showed that both the hexane extract and the ethyl acetate extract, as well as the fractions, have strong antifeedant and nematicidal effects. Gas chromatography-mass spectrometry analyses of methylated active fractions revealed the presence of a mixture of fatty acids. Authentic standards of detected fatty acids and methyl and ethyl derivatives were tested on target organisms. The most active compounds were decanoic, undecanoic, and dodecanoic acids. Methyl and ethyl ester derivatives had lower effects in comparison with free fatty acids. Dose-response experiments showed that undecanoic acid was the most potent compound with EC50 values of 21 and 6 nmol/cm2 for M. persicae and B. tabaci, respectively, and 192 and 64 nmol for M. incognita and M. javanica, respectively. In a phytotoxicity assay, medium-chain fatty acids caused a decrease of 38–52% in root length and 50–60% in leaf length of L. perenne, but no effects were observed on S. lycopersicum. This study highlights the importance of the genus Eugenia as a source of bioactive metabolites for plant pest management.

GC-MS and SPME-GC/MS Analysis and Bioactive Potential Evaluation of Essential Oils from Two Viola Species Belonging to the V. calcarata Complex

“…It has been reported several times as one of the agents responsible for the phytotoxicity of various EOs [46][47][48][49]. Although present in lower percentages in the EO of V. calcarata and V. dubyana than the previous compounds, decanoic and hexadecanoic acids have already been detected as constituents of samples (EOs, exudates or extracts) capable of selectively reducing the growth of some plant species including weeds [50][51][52].…”

“…Coumarin is a natural compound known for its negative effects on weed germination [56]. Dodecanoic acid in V. dubyana EO showed phytotoxic effect toward some plant species, able to reduce their germination and root development [52]. The inhibitory effects of EOs can be due to the single component but also be related to the mixture of compounds [57].…”

A 2-component blend of coconut oil-derived fatty acids as an oviposition deterrent against Drosophila suzukii (Drosophilidae: Diptera)

“…Although, to our knowledge, this is the first report of the strong oviposition deterrent properties of CFFA on fruit-infesting flies, the antagonistic nature of various fatty acid compounds has been well documented and appears to be widespread among a broad array of hematophagous and phytophagous insects. For phytophagous insects, it has been shown that some fatty acid compounds have oviposition deterrent effects on Delia radicum L. (Cole et al 1989), Ostrinia furnacacalis Guenée (Guo and Li 2009), and Bemisia tabaci Gennadius and Myzus persicae Sulzer (Cruz-Estrada et al 2019). For hematophagous insects, strong repellent activities of CFFA have been shown against a broad array of blood-sucking arthropods, including biting flies, bed bugs, ticks, and mosquitoes (Zhu et al 2018, Roh et al 2020).…”

A Review of the Potency of Plant Extracts and Compounds from Key Families as an Alternative to Synthetic Nematicides: History, Efficacy, and Current Developments

“…Hexane and ethyl acetate extracts of E. winzerlingii are known to be rich in a mixture of fatty acids (decanoic, undecanoic, and dodecanoic acids) which have strong antifeedant and nematicidal properties against RKNs. In particular, Undecanoic acid has been shown to exhibit a significant potency against M. incognita and M. javanica , with EC 50/72h values of 192 and 64 nmol/cm 2 , respectively ( Cruz-Estrada et al, 2019 ). Also, Zouhar et al (2009) demonstrated that EOs of E. caryophyllata possessed nematicidal activity against D. dipsaci , with a significant mortality rate of up to 93% recorded after a 6-h exposure to a 5,000 ppm solution.…”