Synthesis And Biological Activity Of Pentadienone And Chalcone Compounds Containing Quinoxaline Groups

As an important curcumin derivative,pentadienone compounds have a wide range of biological activities such as antibacterial,antitumor,antioxidant,anti-inflammatory,insecticidal,antiviral and insecticidal activities.On the other hand,chalcone compounds have been widely concerned about the control of plant diseases in agricultural production because of their excellent antimicrobial,antiviral,anticancer activity.Quinoxaline is an important of aromatic nitrogen-containing heterocyclic compounds.In this paper,a series of pentadienone derivatives containing quinoxaline（I-1～I-15）and a series of chalcone derivatives containing quinoxaline（II-1～II-28）All compounds were characterized by ¹H NMR,¹³C NMR and HRMS.The semi-leaf spot method was used to test the anti-tobacco mosaic virus（TMV）activity of the synthesized compounds.The results showed that at the test concentration of 500μg/m L,in terms of therapeutic activity,compounds I-1 and II-9against TMV The inhibitory activity was relatively good,55.6 and 53.0%,respectively,higher than that of Ningnanmycin（45.4%）.In terms of protective activity,the inhibitory activities of compounds I-7,I-9 and I-11 on TMV were relatively good,68.3,64.4,and 67.1%,respectively,which were superior to Ningnanmycin（61.4%）.The inhibitory activities of compounds I-9 and II-16 on TMV were relatively good at 85.2 and 80.4%,respectively,which were close to those of Ningnanmycin（89.4%）.The turbidimetric method was used to test the antibacterial activity of the synthesized compounds.The results showed that the EC₅₀values of the compounds I-11,II-2 and II-9 against Xanthomonas axonopodis pv.citri（Xac）were 16.7,6.7 and14.1μg/m L,respectively,are far superior to bismerthiazol（44.3μg/m L）.The EC50values of the compound I-11,II-2 and II-26 on Xanthomonas oryzae pv.oryzae（Xoo）were 33.4,15.1 and 28.8μg/m L,which were far superior to those of xanthozol（42.4μg/m L）.The EC₅₀values of the compounds I-9,II-2 and II-17 against Ralstonia solanacearum（Rs）were 33.8,9.2 and 20.6μg/m L,respectively,which were better than those of xanthozole（62.3μg/m L）.The mechanism of target compounds with good antiviral and bacteriostatic activity has been studied intensively.The micro-thermophoresis experiments have found that the dissociation constant K_d=0.115±0.092μmol/L for compound I-9 and TMV CP,which is better than that of Ningnanmycin.Which shows that there is a good interaction between compound I-9and TMV CP.Scanning electron microscopy experiment results show that the antibacterial mechanism of Compound II-2 on Xac may be through the destruction of bacterial cell membranes,making the bacterial structure dry and damaged,thereby achieving the antibacterial effect.