BR-102024026838-A2 - Chalcone herbicide

BR102024026838A2BR 102024026838 A2BR102024026838 A2BR 102024026838A2BR-102024026838-A2

Abstract

This patent application, belonging to the field of Agriculture, more specifically in its use as a herbicide, refers to the development of a herbicide from 3’-hydroxychalcone (T3), 3’-hydroxy-3,4-dichlorochalcone (Li-9), 3’-hydroxy-4-chlorochalcone (Li-6), 3’-hydroxy-3-pyridylchalcone (Li-45), 3’-hydroxy-4-pyridylchalcone (Li-46), 3’-hydroxy-4-nitrochalcone (Li-58), 3’-hydroxy-4-bromochalcone (LR-72), 4’-hydroxy-3:-methoxychalcone (CH1), 3,4-dimethoxychalcone (CH2) or cinnamaldehyde (P1) for the control of weeds. Herbicidal activity was evaluated using a dose-response curve constructed from solutions at concentrations of 0, 5, 10, 25, 50, and 100 pmol L⁻¹ in 0.1% ethanol. The chalcone 4'-hydroxy-3'-methoxychalcone (CH1) was the most potent in inhibiting root growth, with an IC50 of 17.3 pmol L⁻¹ in Arabidopsis thaiiana. The mode of action was evaluated; the chalcones and the parietal substance (cinnamaldehyde) of chalcone CH1 caused the formation of elongated cells and showed a lower proportion of cells in the mitotic phases.

Inventors

LUIS OCTAVIO REGASINI
RAPHAEL MOTA GARRIDO
ROSANA MARTA KOLB
FRANCK EMMANUEL DAYAN

Assignees

UNIVERSIDADE ESTADUAL PAULISTA JULIO DE MESQUITA FILHO
COLORADO STATE UNIVERSITY RESEARCH FOUNDATION

Dates

Publication Date: 20260310
Application Date: 20241219
Priority Date: 20240829

Claims (2)

1. CHALCONE HERBICIDE, characterized by the fact that it has in its composition at least one substance with herbicidal activity selected from: 3’-hydroxychalcone (T3), 3’-hydroxy-3,4-dichlorochalcone (Li-9), 3’-hydroxy-4-chlorochalcone (Li-6), 3’-hydroxy-3-pyridyl-chalcone (Li-45), 3’-hydroxy-4-pyridyl-chalcone (Li-46), 3’-hydroxy-4-nitrochatoone (Li-58), 3’-hydroxy-4-bromochalcone (LR-72), 4’-hydroxy-3!-methoxychalcone (CH1), 3,4-dimethoxychalcone (CH2) or cinnamaldehyde (P1).
2. USE OF THE HERBICIDE, characterized by the fact that it is used in agriculture for the control of weeds.

Description

INTRODUCTION [001] This patent application relates to the identification of the herbicidal substances 3’-hydroxychalcone (T3), 3’-hydroxy-3,4-dichlorochalcone (Li-9), 3’-hydroxy-4-chlorochalcone (Li-6), 3’-hydroxy-3-pyridyl-chalcone (Li-45), 3’-hydroxy-4-pyridyl-chalcone (Li-46), 3’-hydroxy-4-nitrochalcone (Li-58), 3’-hydroxy-4-bromochalcone (LR-72), 4’-hydroxy-3’-methoxychalcone (CH1), 3,4-dimethoxychalcone (CH2) and cinnamaldehyde (P1) for the control of weeds. FIELD OF APPLICATION [002] The main area of application for this technology is in agriculture, more specifically as a herbicide intended for weed control. STATE OF THE ART [003] The widespread use of different herbicides on the market, which target the same mechanism of action for weed control, over time promotes the emergence of resistant weeds. Herbicide resistance is a normal and predictable result of natural selection. Worldwide, more than 200 weed species have already developed resistance to one or more herbicides. And currently, herbicides have already found resistance in 21 of the 25 known molecular targets for weed control. [004] Weed control is essential for good yields in world food production (CHOTSAENG et al., 2018; GARRIDO et al., 2023). Weeds have caused serious economic losses, more than any other agricultural pest (DIN et al., 2017; NGUYEN et al., 2016). [005] The development of new phytotoxic agents with different molecular pathways has recently become the main and constant objective of weed control research in recent decades (DAYAN et al., 2009; DIAZ-TIELAS et al., 2012; GOMES et al., 2018), in addition to changes in management programs (HEAP, 2014). Pesticides based on natural products are generally water-soluble and have a relatively short half-life (BHOWMIK; INDERJIT, 2003), since their chemical structures do not have "unnatural" rings and contain few halogen substituents (DAYAN et al., 2009). Due to these characteristics, they are considered safe from an environmental toxicology point of view (BHOWMIK; INDERJIT, 2003). Furthermore, they could be obtained from natural extracts or synthesized in the laboratory (COPPING; DUKE, 2007). Many chemical molecules produced by plants act similarly to herbicides in the metabolism of other plants, and botanical studies characterize some of these substances as good inhibitory agents (BITENCOURT et al., 2007). For example, 2,4'-dimethoxychalcone reduced the germination of Mimosa pudica L. and Senna obtusifolius L. seeds by 58% and 48%, respectively (BITENCOURT et al., 2007). [006] Chalcones are multifunctional molecules with diverse molecular targets and a broad spectrum of biological activities, exhibiting bactericidal, antifungal, anthelmintic, insecticidal, and antiviral actions (DIAZ-TIELAS et al, 2016). They also exhibit good phytotoxic potential and are relatively easy to synthesize. OBJECTIVES OF THE INVENTION [007] The central objective of this invention is to advance the development of herbicides derived from 3:-hydroxychalcone (T3), 3'-hydroxy-3,4-dichlorochalcone (Li-9), 3'-hydroxy-4-chlorochalcone (U-6), 3’-hydroxy-3-pyridyl-chalcone (Li-45), 3’-hydroxy-4-pyridyl-chalcone (Li-46), 3’-hydroxy-4-nitrochalcone (Li-58), 3'-hydroxy-4-bromochalcone (LR-72), 4'-hydroxy-3!-methoxychalcone (CH1), 3,4-dimethoxychalcone (CH2) or cinnamaldehyde (P1). ADVANTAGES OF THE INVENTION [008] The chalcones identified are synthetic and have a structure similar to natural products. These substances are presented as alternatives to weed control by herbicides currently on the market, given that many species already exhibit resistance to them or may develop resistance in the future. DETAILED DESCRIPTION OF THE FIGURES [009] Figure 1 shows the chemical structures of methoxychalcones and cinnamaldehyde. Figure 1A shows the chemical structure of the substance 4'-hydroxy-3'-methoxychalcoπa (CH1), Figure 1B the chemical structure of the substance 3,4-dimethoxychalcone (CH2) and Figure 1C the chemical structure of cinnamaldehyde (P1). [010] Figure 2 shows photographs displaying Arabidopsis thauna seedlings growing in 0.44% macro and micronutrients, with 1% sucrose in 1% agar. Negative controls (ethanol 0.1%) (Figures 2A, 2B and 2C) and substances at 100 μmol L1 (Figure 2D cinnamaldehyde), (Figure 2E 3,4-dimethoxychalcone) and (Figure 2F 4'-hydroxy-3'-methoxychalcone); grid spacing is 1 cm. [011] Figure 3 shows graphs displaying the dose-response curve of 4'-hydroxy-3'-methoxychalcone (CH1) (Figure 3A), 3,4-dimethoxychalcone (CH2) (Figure 3B), cinnamaldehyde (P1) (Figure 3C) and all substances superimposed (Figure 3D). [012] Figure 4 is a graph showing the effect of cinnamaldehyde (P1), 4'-hydroxy-3'-methoxychalcone (CH1) and 3,4-dimethoxychalcone (CH2) on phenylalanine ammonia-lyase (PAL) activity. The negative control consisted of enzyme, assay buffer and 0.5% ethanoi. The positive control (PC) consisted of enzyme, assay buffer and perchloric acid. Different letters at the top of the bars indicate significant