Synthesis and Phytotoxic Evaluation of Isatin Derivatives Supported by 3D-QSAR Study

Concerned about weed infestation, a major threat to food production and herbicide resistance that interferes in the mechanism of action of the main herbicides, we have synthesized eight isatin derivatives using the Click Chemistry approach through copper-catalyzed azide-alkyne cycloadditions (CuAAC). Sixteen isatin derivatives were evaluated for their phytotoxic activity against the seed culture of the model plants, Lactuca sativa and Allium cepa. Six of them showed phytotoxic activity similar to the positive control, trifluralin. Hypocotyl length measurement analysis in L. sativa revealed that triazole derivative 8 is more active than trifluralin. For A. cepa, root length measurement analyses revealed that 3, 10, 14, 16, and 17 were similar to the positive control (CoMFA) model construction using the acetolactate synthase (ALS) crystallographic structure displayed plci values of predicted inhibitory activity and contour maps revealing sterically bulky groups for 11, the CF3 group in ortho, and for 17, Br in ortho, favoring the inhibitory ALS activity.

Automated summary

To address the issues of weed infestation and herbicide resistance, the authors synthesized eight isatin derivatives using Click Chemistry. These derivatives were evaluated for their phytotoxic activity against two model plants, Lactuca sativa and Allium cepa. Six derivatives showed similar activity to the positive control trifluralin, with compound 8 being more active than trifluralin in L. sativa. ALS crystallographic structure analysis revealed the inhibitory activity of compounds 11 and 17 against A. cepa.