Evaluation of the phytotoxic and antifungal activity of C₁₇‐sesquiterpenoids as potential biopesticides

Abstract

BACKGROUND Natural products are a promising source for the development of new pesticides with alternative mechanisms of action. In this study, we evaluated the phytotoxic and antifungal activity of a novel family of natural C17‐sesquiterpenoids and performed a study of the effect caused by the elimination of the α‐methylene‐γ‐butyrolactone system and its importance to their biological activity. RESULTS Many tested compounds exhibited a strong phytotoxic activity. Lappalone and pertyolide B were the most potent molecules from the tested group. Lappalone displayed a strong inhibition profile against selected weed species, reaching a half‐maximal inhibitory concentration (IC50) value of 5.0 μm against Echinochloa crus‐galli L. shoot and 5.7 μm against the germination rate of Amaranthus viridis L., as well as a good stimulation of the germination of Phelipanche ramosa L. Pertyolide B demonstrated excellent inhibition against Amaranthus viridis L. (IC50: 56.7, 70.3 and 24.0 μm against the root and shoot growth, and germination rate, respectively) and Allium cepa L. (representative of the Liliaceae family, with IC50 values of 25.3 and 64.4 μm against root and shoot growth). Regarding the antifungal activity, pertyolide B presented significant activity against Colletotrichum fragareae and Fusarium oxysporum with a minimum inhibitory concentration of 6.6 μg μL−1. CONCLUSION The bioassays revealed that frequently the presence of the α‐methylene‐γ‐butyrolactone system is not essential for the bioactivities of sesquiterpene lactones, and suggest that C17‐sesquiterpenoids may function through a different mechanism of action not related to the widely assumed Michael addition. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Bioprospection of Phytotoxic Plant-Derived Eudesmanolides and Guaianolides for the Control of Amaranthus viridis, Echinochloa crus-galli, and Lolium perenne Weeds

“…In this work, 17 compounds (Figure ) were evaluated in bioassays, including the nonhydroxylated compounds 1 , 4 , 6 , and 9 (the phytotoxicity of DHC, 10 , against the tested weeds was reported previously). , The weed species studied belong to harmful species for agriculture worldwide. A.…”

“…25 In this work, 17 compounds (Figure 2) were evaluated in bioassays, including the nonhydroxylated compounds 1, 4, 6, and 9 (the phytotoxicity of DHC, 10, against the tested weeds was reported previously). 26,27 The weed species studied belong to harmful species for agriculture worldwide. A. viridis (slender amaranth) is a prevalent weed in warm temperature regions and is considered to be a major problem for agriculture as it affects more than 50 crops, causes significant biomass loss, and has a fast infestation; 28,29 E. crus-galli (barnyard grass) is one of the most noxious weeds in modern agriculture, and it affects relevant crops like rice, is dispersed worldwide, and has a tendency to grow in harsh climates; 30,31 and L. perenne (ryegrass), the major weed that affects wheat production worldwide.…”

Plant Growth Inhibitory Activity of Hibiscus sabdariffa Calyx and the Phytotoxicity of Hydroxycitric Acid Lactone

“…Farmers have struggled with weeds intensively since the dawn of agriculture [5], and the control of weeds, therefore, poses a challenging issue for sustainable agriculture [6,7]. Since the discovery of synthetic herbicides, they have become among the most widely used weed-control strategies in most countries [8,9]. Over two hundred functional substances had been recorded for herbicidal applications [9,10].…”

“…Since the discovery of synthetic herbicides, they have become among the most widely used weed-control strategies in most countries [8,9]. Over two hundred functional substances had been recorded for herbicidal applications [9,10]. However, weeds could develop resistance to synthetic herbicides [9].…”

“…Over two hundred functional substances had been recorded for herbicidal applications [9,10]. However, weeds could develop resistance to synthetic herbicides [9].…”