Structure-Activity Relationship Study of Xanthoxyline and Related Small Methyl Ketone Herbicides

Chotpatiwetchkul, Warot; Chotsaeng, Nawasit; Laosinwattana, Chamroon; Charoenying, Patchanee

doi:10.1021/acsomega.2c02704

Structure-Activity Relationship Study of Xanthoxyline and Related Small Methyl Ketone Herbicides

Author(s)

Chotpatiwetchkul, Warot

Chotsaeng, Nawasit

Laosinwattana, Chamroon

Charoenying, Patchanee

Date Issued

August 23, 2022

Type

Article

DOI

10.1021/acsomega.2c02704

Abstract

Xanthoxyline (1), a small natural methyl ketone, was previously reported as a plant growth inhibitor. In this research, related methyl ketones bearing electron-donating and electron-withdrawing groups, together with heteroaromatics, were investigated against seed germination and seedling growth of Chinese amaranth (Amaranthus tricolor L.) and barnyard grass [Echinochloa crus-galli (L.) Beauv]. The structure-activity relationships (SARs) of methyl ketone herbicides were clarified, and which types and positions of substituents were crucially important for activity were also clarified. Indole derivatives, namely, 3-acetylindole (43) and 3-acetyl-7-azaindole (44) were found to be the most active methyl ketones that highly suppressed plant growth at low concentrations. The molecular docking on the 4-hydroxyphenylpyruvate dioxygenase (HPPD) enzyme indicated that carbonyl, aromatic, and azaindole were key interactions of HPPD inhibitors. This finding would be useful for the development of small ketone herbicides.

Citation

ACS Omega, 7(33), 29002-29012, 2022