(Z)-/(E)-胡椒酮基吡唑-肟酯化合物的合成及其抑菌活性研究OA北大核心CSTPCD

Using piperitone as the raw material,42 novel(Z)-/(E)-piperitone-based pyrazole-oxime ester(compounds 6a-6u,including 21 pairs of Z/E isomers)were synthesized through O-acylation reactions with substituted pyrazoles after carbonyl oximation.The structures of the target products were characterized using proton-1 nuclear magnetic resonance spectrum(1 H NMR),carbon-13 nuclear magnetic resonance spectrum(13 C NMR),Fourier-transform infrared spectroscopy(FT-IR),and high-resolution mass spectrometry(HRMS).The Z/E configurations of the compounds were determined by single-crystal X-ray diffraction analysis(SC-XRD).In vitro bioactivity tests showed that the(Z)-/(E)-piperitone-based pyrazole-oxime ester compounds exhibited certain antifungal activities against eight plant pathogenic bacteria,including Fusarium oxysporum,Cercospora arachidicola,Physalospora piricola,Alternaria solani,Gibberella zeae,Rhizoctonia solani,Bipolaris maydis,and Colleterichum orbiculare,at a mass concentration of 50 mg/L.The antibacterial activity was significantly influenced by the Z/E configurations of the compounds,and their activities against A.solani were found to be the most efficient.Wherein,(Z)-piperitone-based(3′,5′-difluoromethyl)phenyl pyrazole-oxime ester((Z)-6o),(Z)-piperitone-based(p-trifluoromethyl)phenyl pyrazole-oxime ester((Z)-6u),(Z)-piperitone-based(p-nitro)phenyl pyrazole-oxime ester((Z)-6p),(E)-piperitone-based(p-nitro)phenyl pyrazole-oxime ester((E)-6p),(Z)-piperitone-based(p-trifluoromethoxy)phenyl pyrazole-oxime ester((Z)-6g),and(E)-piperitone-based(o-fluoro)phenyl pyrazole-oxime ester((E)-6i)exhibited the inhibition rates of 83.8%,78.7%,76.3%,76.3%,74.8%,and 74.3%,respectively,against A.solani.And compound(Z)-6u showed the inhibition rate of 82.5%against P.piricola,which was better than that of the positive control chlorothalonil.The three-dimensional quantitative structure-activity relationship(3D-QSAR)model(r2 = 0.928,q2 = 0.732)for the inhibitory activity of(Z)-piperitone-based pyrazole-oxime ester compounds against A.solani was established using comparative molecular field analysis(CoMFA)method.