Design, Synthesis, and Biological Activity of Novel Triketone-Containing Phenoxy Nicotinyl Inhibitors of HPPD.

4-Hydroxyphenylpyruvate dioxygenase (HPPD) is a crucial target enzyme in albino herbicides. The inhibition of HPPD activity interferes with the synthesis of carotenoids, blocking photosynthesis and resulting in bleaching and necrosis. To develop herbicides with excellent activity, a series of 3-hydroxy-2-(6-substituted phenoxynicotinoyl)-2-cyclohexen-1-one derivatives were designed via active substructure combination. The title compounds were characterized via infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopies, and high-resolution mass spectrometry. The structure of compound III-17 was confirmed via single-crystal X-ray diffraction. Preliminary tests demonstrated that some compounds had good herbicidal activity. Crop safety tests revealed that compound III-29 was safer than the commercial herbicide mesotrione in wheat and peanuts. Moreover, the compound exhibited the highest inhibitory activity against Arabidopsis thaliana HPPD (AtHPPD), with a half-maximal inhibitory concentration of 0.19 µM, demonstrating superior activity compared with mesotrione (0.28 µM) in vitro. A three-dimensional quantitative structure-activity relationship study revealed that the introduction of smaller groups to the 5-position of cyclohexanedione and negative charges to the 3-position of the benzene ring enhanced the herbicidal activity. A molecular structure comparison demonstrated that compound III-29 was beneficial to plant absorption and conduction. Molecular docking and molecular dynamics simulations further verified the stability of the complex formed by compound III-29 and AtHPPD. Thus, this study may provide insights into the development of green and efficient herbicides.

Association between interpersonal relations and anxiety, depression symptoms, and suicidal ideation among middle school students.

Objective: This study aimed to explore the relationship between different types of interpersonal relationships and anxiety symptoms, depressive symptoms, and suicidal ideation and discusses the impact of different grades among middle school students. Methods: The Patient Health Questionnaire Depression Scale, the Chinese version of the Generalized Anxiety Scale, suicidal ideation questions, and interpersonal relations items were used to measure the depression symptoms, anxiety symptoms, suicidal ideation, and interpersonal relations of the participants. The variables of anxiety symptoms, depressive symptoms, suicidal ideation, and interpersonal relations were screened using the Chi-square test and principal component analysis. AMOS17.0 constructs the path of the association between interpersonal relations and depressive symptoms, anxiety symptoms, and suicidal ideation. Results: The mother-child relationship had direct impacts of -0.06, -0.07, and -0.06 on anxiety symptoms, depressive symptoms, and suicidal ideation. On anxiety symptoms, depressive symptoms, and suicidal ideation, the direct impacts of the father-child relationship were -0.09, -0.03, and -0.08. Moreover, the direct effects of peer relationships on depressive symptoms were -0.04, whereas the direct impact of teacher-student relationships on anxiety and depressive symptoms were -0.10 and -0.09. Further pathway analysis based on grade level showed that in the junior high school model, the direct effect of the mother-child relationship on anxiety and depressive symptoms was -0.18 and -0.16. The direct impact of the father-child relationship on depressive symptoms and suicidal ideation was -0.08 and 0.09. The direct effect of peer relationships on depressive symptoms was -0.08, and the direct impact of the teacher-student relationship on anxiety symptoms was -0.06. In the high school model, the direct effect of the mother-child relationship on suicidal ideation was -0.07, while the direct impact of the father-child relationship on anxiety, depression, and suicidal ideation was -0.10, -0.07, and -0.12, respectively. In addition, the direct effects of peer relationships on anxiety and depression were -0.06 and -0.05, and the direct impact of teacher-student relationships on anxiety and depression was -0.10 and -0.11. Conclusion: The father-child relationship affects suicidal ideation and depression the most, followed by the mother-child relationship, the teacher-student interaction, and the peer relationship. The teacher-student relationship influences anxiety symptoms the most, followed by the father-child and mother-child relationships. The association between interpersonal interactions and anxiety, depressive symptoms, and suicidal ideation varied significantly across grade levels.