We report the synthesis of twelve indole derivatives bearing nitro or amide groups via Fischer indole methodology followed by reduction/acetylation and amidation reactions. After thorough ...characterization, these indoles were subjected to a number of studies in order to evaluate their bioactive potential as photosynthesis and plant growth inhibitors. Firstly, these molecular hybrids were evaluated as photosystem II (PSII) inhibitors through chlorophyll a (Chl a) fluorescence measurement. In this study, 6‐chloro‐8‐nitro‐2,3,4,9‐tetrahydro‐1H‐carbazole (15a) and 5‐chloro‐2,3‐dimethyl‐7‐nitro‐1H‐indole (15b) showed the best results by reducing the phenomenological parameters of reaction centers ABS/RC, TR0/RC and ET0/RC of PSII. Electron chain blockage by these compounds may lead to diminished ATP synthesis and CO2 fixation which interrupt the plant development. The compounds 15a and 15b both act as postemergent herbicides, reducing the dry biomass of Ipomoea grandifolia and Senna alata weeds by an average of 40% and 37%, respectively, corroborating the fluorescence results. Additionally, the molecular docking study revealed that the presence of strong electron‐withdrawing groups at the indole phenyl ring is important for the ligand’s interaction with the binding pocket of protein D1 on PSII. The optimization of these molecular features is the goal of our research group in further understanding and development of new potent herbicides.
This work reports the synthesis of indole nitrogen hybrids and their bioactive potential as photosystem inhibitors. The molecular hybrids were evaluated as photosystem II inhibitors through chlorophyll a fluorescence measurements and plant growth inhibitors. Compounds 6‐Chloro‐8‐nitro‐2,3,4,9‐tetrahydro‐1H‐carbazole and 5‐chloro‐2,3‐dimethyl‐7‐nitro‐1H‐indole showed the best results by reducing the phenomenological parameters of the reaction center, diminishing ATP synthesis and CO2 fixation which interrupt the plant development. Additionally, the molecular docking study revealed that the presence of strong electron withdrawing groups at the indole phenyl ring are important for the ligands’ interaction with the binding pocked of protein D1.
Pretendemos avaliar quais as percepções dos participantes sobre uma mostra de experimentos de física bem como quais experimentos os participantes apresentaram facilidade de entendimento. Utilizamos ...um questionário para coletar os dados. Os participantes consideraram válida a iniciativa dos experimentos e ficaram satisfeitos com as explicações fornecidas pelos professores mediadores. As teorias associadas às experiências do circuito elétrico e motor elétrico obtiveram maior facilidade de entendimento dos participantes, enquanto os mesmos obtiveram dificuldade para compreender a teoria relacionada à atividade proposta no movimento no trilho de ar (colisão) e a prática experimental de difração. Sugestões de experimentos foram fornecidas pelos participantes para a próxima mostra de experimentos; como, por exemplo, experimentos relacionados à geração e transmissão de energia elétrica; bobina de tesla; toróide e experimentos de eletrônica. Como perspectiva futura, pretendemos orientar os participantes na construção de alguns experimentos de física, para que os mesmos possam ser doados para escolas públicas do ensino fundamental e médio, que carecem de laboratório de física.
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