Abstract
A series of novel N-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)-amide derivatives were synthesized by a simple approach from 1,8-naphthalic anhydride and their organic acids in high yield. The chemical structures of the products were elucidated by NMR and HR-ESI-MS, and their purity were checked with the melting points. Their plant growth regulating activity and fungicidal activity were also evaluated. Seed germination tests showed that the seed germination rate of wheat and cucumber can be promoted significantly by these six compounds. The maximal seed germination promotion rates were observed at the concentration of 25 mg/L and 12.5 mg/L for wheat and cucumber, respectively. In addition, 4a, 4b and 4d exhibited the best promoting effects on wheat seedling growth, with the best performance on primary roots, moderate promoting effects on lateral roots. They also exhibited higher cucumber seedling growth activities than DA-6 at 12.5 mg/L. Meanwhile, 4a-d showed a high fungicidal activity against Alternaria solani, Fusarium graminearum, Phytophthora Infestans and Phytophthora capsici at 125 mg/L. All these results revealed that the bioactivity of N-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)-amide derivatives can improve notably with the introduction of phenyl group.
