The novel plant elicitors, 3-benzyl-5-[1-(2-oxo-4-phenyl-1-oxaspiro[4.5]dec-3-en-3-yl)ethylidene]-2-aminoimidazolin-4-one derivatives, were designed based on the diversity-oriented synthesis strategy and synthesized in four steps via the Knoevenagel condensation reaction as the key step. They were characterized by 1H NMR, 13C NMR, HR-ESI-MS, and X-ray diffraction. The position of the CN bond of Z- and E-configuration compounds was determined by X-ray diffraction. The in vivo fungicidal activity evaluation revealed that most of these compounds exhibited remarkable activities (100%) against Pseudoperonospora cubensis at 400 μg/mL, among which compound 8e still exhibited excellent protective activity with a 50% inhibition rate at 0.1 μg/mL. Because the in vitro effect on tested phytopathogens was poor, the mechanism to induce the immune responses and reinforce the resistance of cucumber against Botrytis cinerea was studied. The results indicated that the compound 8e-mediated defense response against B. cinerea was based on the accumulation of pathogenesis-related proteins and cell wall reinforcement by callose deposition. Quantitative analysis of salicylic acid (SA) and jasmonic acid (JA) and the increased expression of induced resistance-related genes and the defense-associated phenylalanine ammonia lyase revealed that the immune response triggered by compound 8e was highly associated with the SA signaling pathway. Significant upregulation of JA-related genes Cs-AOS2 indicated that the JA signaling pathway was also influenced. It was also shown that the plants treated with compound 8e promoted primary root elongation, which resulted in enhanced plant growth. Most importantly, these compounds have completely new structures compared with the traditional plant elicitors. Further research of 8e-mediated plant disease resistance might have a great influence on the development of plant elicitors.

Nanopillars (400–500 nm in diameter, 20–40 in aspect ratio, and 60–90° in slanted angles) were fabricated, whose posture can be actuated by electron beam or external electric field.

A series of novel butenolide compounds containing oxime ether moiety were designed and synthesized through diversity modification of the benzene ring at 4-phenyl and the 3-oxime ether group based on the fungicidal 3-acetyl-4-phenyl-1-oxaspiro[4,5]dec-3-en-2-one oxime ether as the lead structure. Their structures were characterized by 1 H NMR, 13 C NMR, HR-ESI-MS data and X-ray diffraction. The preliminary in vitro bioassay results indicated that some compounds exhibited good fungicidal activities against Thanatephorus cucumeris, Sclerotinia sclerotiorum and Botrytis cinerea. For example, (E)-3-(1-((2-chlorobenzyloxy)imino)ethyl)-4-(pyridin-2-yl)-1-oxaspiro[4.5]dec-3-en-2-one (A7) had EC50 values of 6.02, 8.25 and 15.70 mg/L against T. cucumeris, S. sclerotiorum and B. cinerea, (E)-3-(1-((2-chlorobenzyloxy)imino)ethyl)-4-(pyridin-4-yl)-1-oxaspiro[4.5]dec-3-en-2-one (A8) had EC50 values of 1.31 and 10.62 mg/L against T. cucumeris and S. sclerotiorum, respectively. A7 had an excellent inhibition against spore germination of B. cinerea, and the inhibition rate was 95% at the concentration of 100 mg/L. The in vivo bioassay results showed that compounds A7 had a notable protective activity against tomato gray mould and rice sheath blight disease. Keywords 3-acetyl-4-aryl-1-oxaspiro[4,5]dec-3-en-2-one; oxime ether; synthesis; fungicidal activity 杀菌剂在农业生产中具有举足轻重的作用, 随着杀 菌剂的广泛使用, 病原菌产生了严重的抗药性, 如近年 来应用较多的甲氧基丙烯酸酯类杀菌剂 [1] , 已发现多种 植物病原菌对其产生了严重的抗药性 [2] . 我国在十三五 期间提出的农药减量使用和零增长目标已取得显著的 成效, 在十四五期间仍是农业重点研发计划的重要目 标. 研究开发低抗药性、生态友好、作用机制新颖的绿 色农药成为现代农业发展的迫切需求 [3] , 而发现作用方 式独特、化学结构新颖的农用杀菌剂是其重要发展方向 之一 [4] . 丁烯内酯属于 α,β-不饱和内酯类化合物, 又称 为 2(5H)-呋喃酮类化合物, 是一个具有优良生物活性的 结构单元, 广泛存在天然产物中, 如二萜内酯类化合物

The first total synthesis of Sch 53825 (14) was achieved in 12 steps from 5-hydroxy-1-tetralone in 16% overall yield through N-benzyl cinchoninium chloride-catalyzed asymmetric epoxidation and a Mitsunobu reaction as the key steps.

In order to improve the antifungal activity of new butenolides containing oxime ether moiety, a series of new butenolide compounds containing methoxyacrylate scaffold were designed and synthesized, based on the previous reports. Their structures were characterized by 1H NMR, 13C NMR, HR-MS spectra, and X-ray diffraction analysis. The in vitro antifungal activities were evaluated by the mycelium growth rate method. The results showed that the inhibitory activities of these new compounds against Sclerotinia sclerotiorum were significantly improved, in comparison with that of the lead compound 3–8; the EC50 values of V-6 and VI-7 against S. sclerotiorum were 1.51 and 1.81 mg/L, nearly seven times that of 3–8 (EC50 10.62 mg/L). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observation indicated that compound VI-3 had a significant impact on the structure and function of the hyphal cell of S. sclerotiorum mycelium and the positive control trifloxystrobin. Molecular simulation docking results indicated that the introduction of methoxyacrylate scaffold is beneficial to improving the antifungal activity of these compounds against S. sclerotiorum, which can be used as the lead for further structure optimization.