UHPLC-OrbiTrap MS Characterization of Phenolic Profiles in French Marigold Extracts and Analysis of Their Antifeedant Activity against Colorado Potato Beetle

Abstract

French marigold is an aromatic plant rich in polyphenolic secondary metabolites, which pesticidal potential was examined in this study. Ultra-high-performance liquid chromatography (UHPLC) connected with OrbiTrap mass spectrometer (MS) identified 113 phenolics and revealed the most detailed phytochemistry of French marigold published so far. Depending on plant material (flowers or leaves) and solvents used for extraction (water, methanol, dichloromethane), the phenolic composition varied. Methanol extract of flowers, with 89 identified phenolics and high antioxidant activity statistically comparable with positive control Trolox, was chosen for testing of antifeedant potential against the 3rd and 4th instars of Colorado potato beetle (CPB). A significant reduction in final body mass of 4th larval stage fed with potato leaves coated with methanol extract of flowers in the concentration of 10 mg/mL was observed (157.67 mg vs. 182.26 mg of controls fed with non-treated leaves). This caused delayed molting since treated larvae reached the maximal mass a day after controls and this delay persisted during the entire larval development. Continuous feeding caused a 25% decline in digestive proteolytic activity of the 4th instar in comparison to controls. The results suggest that French marigold methanol extract of flowers could be proposed as a promising antifeedant for CPB management, with an impact on the reduction in the environmental footprint associated with synthetic pesticide application.

A Brief Review of Efficacious Plants in the World: <i>Tagetes</i> (Marigold)

“…Some important chemical agents are found in the marigold extract, such as phenylpropanoids, carotenoids, flavonoids, thiophenes, quercetagetin, 6-hydroxykaempferol, quercetin, patuletin, quercetagetin-7-Oglucoside and others (Bhave et al 2020;Ratananikom et al 2021;Devrnja et al 2022). The compound produced by plants could vary depending on some factors: part of plant extracted, harvesting seasons, plant development stage, and geographical conditions (Salehi et al 2018).…”

“…Tagetes patula L. (French marigold) is an aromatic plant species that consists of many secondary metabolites and has the potential for pesticidal activities (Devrnja et al 2022). The use of extracted leaf from Tagetes patula L. using water as a solvent has also been effectively used as bio-controlling agent against various diseases in tomato plants.…”

Encapsulation of Fennel and Basil Essential Oils in β-Cyclodextrin for Novel Biopesticide Formulation

“…These metabolites, accumulated in different parts of the plant, are components of plant extracts or essential oils (EOs) and frequently manifest toxicity, act as antifeedants through pest metabolism alternation and fitness reduction, or simply deter or repel insect pests [ 10 , 11 , 12 ]. EOs, as complex mixtures of volatile compounds, have been shown to display insecticidal properties against various pests [ 13 , 14 , 15 ]. They are already recognized as potential biopesticides involved in sustainable agriculture [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ], but with challenging requirements to adapt results from laboratories to fluctuating outdoor conditions.…”

Eggplant’s foliar chlorogenic acid provides resistance against the tropical armyworm

“…Worldwide, ~385 million unintentional severe pesticide poisoning cases including around 11,000 fatalities are reported 14 . Approximately 0.4 million tons of insecticides produced annually increase pesticide residue contamination and cause health hazards, which endangers beneficial insects and pollutes the environment [15][16][17] . Owing to the hazards of synthetic pesticides, the demand for biopesticides, the pest management agents based on living organisms or natural products, is increasing.…”