Evaluation of Chalcone Derivatives as Photosynthesis and Plant Growth Inhibitors

Abstract

We report the evaluation of chalcone derivatives as photosystem II (PSII) and plant growth inhibitors. Chalcone derivatives were evaluated as PSII inhibitors through Chl a fluorescence measurement. (E)-Chalcone (6a) and (E)-3-(4-bromophenyl)-1-(4-fluorophenyl)prop-2-en-1-one (6j) showed the best results, reducing the performance index on absorption basis parameter (PI abs ) by 70 %. Additionally, the decrease of TR 0 /RC and ET 0 / RC parameters indicates that the chalcone derivatives limited the number of active PSII reaction centers and the amount of trapped energy within them. Compounds 6a and 6j both act as post-emergent herbicides at 50 μM, reducing the root biomass of the Ipomoea grandifolia weed by 72 % and 83 %, respectively, corroborating the fluorescence results. The selectivity against weeds as compared to valuable crops by compounds 6a and 6j were evaluated employing Zea mays and Phaseolus vulgaris plants. In these, our newly synthesized compounds showed no effects on biomass accumulation of roots and aerial parts when compared to the control, providing valuable evidence for the role of these compounds as selective inhibitors of the growth of undesired weeds.

Advances in the Synthesis of Heteroaromatic Hybrid Chalcones

“…In an examination of chalcones with potential anticancer properties, Bukhari prepared a diverse set of furyl-, thienyl-, benzofuryl, and benzothienyl-1,4-pyrazinyl chalcones 116 in yields ranging from 42 to 75%. Extending that work to include condensations of 4-heteroaromatic acetophenones 117 with pyrazine carbaldehyde 115 gave rise to an array of hybrid chalcones 118 in moderate yields [ 18 ]. See Scheme 39 .…”

“…has been investigated thoroughly over the years, with numerous research articles as well as several reviews appearing in the last decade describing the current chalcone synthetic strategies, the heterocycles derived from them, and the bioactivity and pharmaceutical uses of these compounds [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Within that context, the preparation of more highly functionalized chalcones that contain heteroaromatic components has been an area of intense research over the last decade [ 10 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ].…”

“…Research has established that heteroaromatic hybrid chalcones themselves possess broad medicinal value as anticancer [ 16 , 19 , 23 ], antimicrobial [ 11 , 20 , 23 , 28 ], antifungal [ 16 ], anti-tuberculosis [ 25 ] and anti-inflammatory agents [ 22 ] as well as having other important pharmacological functions [ 9 , 10 ], agrochemical utility as photosynthesis inhibitors [ 18 ] and industrial use as photoinitiators in 3D printing [ 17 ]. Figure 2 shows a representative selection of heteroaromatic hybrid chalcone pharmacophores and industrially important compounds.…”

2-Hydroxychalcone as a Novel Natural Photosynthesis Inhibitor against Bloom-Forming Cyanobacteria

“…15,17 A recent paper evaluated chalcone derivatives as photosynthesis inhibitors judging from Chl a fluorescence measurement. 18 Knowledge of its mode of action and molecular site of action is limited.…”

“…Chalcones (1,3-diphenyl-2-propen-1-ones), naturally occurring α,β-unsaturated carbonyl compounds, are abundant in fruits, vegetables, and some traditional herbal medicines (e.g., Angelica, Scutellaria, Glycyrrhiza) . These compounds can also be obtained synthetically through a number of methodologies, for example, Claisen–Schmitt condensation, providing easy access to a broad structural diversity. , Natural and synthetic compounds with a chalcone-based structure are noted for their great pharmacological potential such as antioxidant, anti-inflammatory, and anticancer properties. , A recent paper evaluated chalcone derivatives as photosynthesis inhibitors judging from Chl a fluorescence measurement . Knowledge of its mode of action and molecular site of action is limited.…”