ntic compoundsH NMR (H, ppm)a)MS (m/z)b) 424 (M+)7.38 (1H, dd, J=7.8 Hz), 7.28 (2H, d, J=8.five Hz), 7.26 (1H, m, J=6.1 Hz), 7.09 (2H, dd, J=7.7 Hz), 6.71 (1H, dd, J=8.5 Hz), three.87 (3H, s), 2.75 (2H, t, J=6.four Hz), two.43 (2H, s), two.02.08 (2H, m, J=6.four Hz)M-9.73 (1H, s), 7.43 (1H, d, J=4.five Hz), 7.35 (1H, dd, J=4.5 and eight.1 Hz), 7.05 (4H, dd, J=2.four and 42.9 Hz), six.66 (1H, d, J=8.1 Hz), 2.55.65 (2H, m), two.60.48 (2H, m), 1.92.02 (2H, m)411 (M+H+)M-7.54 (2H, m), 7.27 (4H, dd, J=9.0 and 56.7 Hz), 6.61 (1H, d, J=8.four Hz), 3.86 (3H, s)331 (M+H+)Genuine 5-HT6 Receptor Modulator Biological Activity compounds have been synthesized by Kumiai Chemical Sector Co., Ltd. (Shizuoka, Japan). a) 1H NMR spectrum of fenquinotrione (in CDCl3) was measured on a JEOL JNM-LA-400 (400 MHz) spectrometer. 1H NMR spectra of M-1 and M-2 (in DMSO d6) had been measured on JEOL JNM-LA-300 (300 MHz) spectrometer. b) EI-MS spectrum of fenquinotrione was measured on a JEOL JMS-SX-102. ESI-MS spectra fo M-1 and M-2 were measured on Thermo Fisher Scientific Q Exactive Focus Mass spectrometry.Vol. 46, No. 3, 24957 (2021)Mechanism of action and selectivity of fenquinotrionevested by centrifugation (6,000 g at 4 for 10 min) and stored at -80 . Escherichia coli cell pellets were suspended in a B-PER Bacterial Protein Extraction Reagent (Thermo Fisher Scientific) containing 0.two mg/mL lysozyme, DTT (1 mM), a protease inhibitor cocktail (Sigma-Aldrich, MO, USA), and Cryonase Coldactive Nuclease (TaKaRa Bio Inc.). This suspension was centrifuged at six,000 g at four for 10 min. A recombinant His-tagged AtHPPD protein was purified by affinity chromatography making use of a HisTrap FF column (GE Healthcare Bioscience, NJ, USA).reaction mixture without having the compound was utilized as a optimistic control. Inhibition of HPPD activity was determined by comparison together with the optimistic control. 6. Molecular docking study The AtHPPD crystal structure (PDB ID: 1TFZ) in complicated with an existing inhibitor, DAS8697) (2-tert-butyl-4-[3-(4methoxyphenyl)-2-methyl-4-methylsulfonylbenzoyl]-1Hpyrazol-3-one), which was obtained from the Protein Information Bank, was applied as the receptor protein. Docking simulation was performed making use of the CDOCKER module of Discovery Studio ver. 4.five (Dassault Systems, V izy-Villacoublay, France). The receptor protein was prepared by eliminating the water molecules, adding hydrogen, and correcting the lacking amino acid residues applying the “Clean Protein” tool inside the “Prepare Protein” module. Later, the protein was assigned making use of a CHARMM force field. After removing DAS869 from the protein, its cavities were predicted utilizing the “From Receptor Cavities” tool inside the “Define and Edit Binding Site” module. Of all the predicted cavities, Web site 1 was selected because the active internet site with reference to the position of DAS869 in 1TFZ. The obtained receptor was employed because the “Input Receptor” molecule parameter. DAS869 and fenquinotrione have been applied because the “Input Ligand” parameters. All other parameters were the default settings. 7. Phylogenetic evaluation of amino acid sequences Phylogenetic evaluation with the HPPD amino acid sequences of rice, ROCK site Arabidopsis, and also other plants like corn, sorghum, wheat, barley, soybean, tomato, carrot, lettuce, rapeseed, millet, alfalfa, and velvetleaf was performed utilizing the ClustalW algorithm. eight. Comparison with the physicochemical properties and biological effects of fenquinotrione derivatives on plants The paddy soil was placed inside a 50 cm2 plastic pot. An acceptable volume of water was added to the soil. Monochoria vaginalis and Schoenoplectus j