RT journal article T1 Evaluation of the phytotoxic and antifungal activity of C-17-sesquiterpenoids as potential biopesticides A1 Cárdenas, David M. A1 Bajsa-Hirschel, Joanna A1 Cantrell, Charles L. A1 Rial Cumbrera, Carlos A1 Varela Montoya, Rosa María A1 González Molinillo, José María A1 Macías Domínguez, Francisco Antonio A2 Química Orgánica K1 C17-sesquiterpenoids K1 natural products K1 pest control K1 pesticide AB 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 C-17-sesquiterpenoids and performed a study of the effect caused by the elimination of the alpha-methylene-gamma-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 mu m against Echinochloa crus-galli L. shoot and 5.7 mu m 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 mu m 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 mu m 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 mu g mu L-1. CONCLUSION The bioassays revealed that frequently the presence of the alpha-methylene-gamma-butyrolactone system is not essential for the bioactivities of sesquiterpene lactones, and suggest that C-17-sesquiterpenoids may function through a different mechanism of action not related to the widely assumed Michael addition. PB WILEY SN 1526-4998 YR 2022 FD 2022-07 LK http://hdl.handle.net/10498/27254 UL http://hdl.handle.net/10498/27254 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 08-nov-2026