Synthesis And Antifungal Activities Of 7-hydroxycoumarin Mannich Base Derivatives

Coumarin and its derivatives widely exist in multiple kinds of natural plants and attract a lot of attention in spices,optical,medicinal,agricultural fields due to their various physical properties and biological activities such as fluorescence properties,antifungal,antiinflammatory,anti-HIV and antitumor activities.Currently,coumarin derivatives have been an important class of organic compounds and it shows a broad prospect to develop low poisonous,efficient,low residual biological pesticide from coumarin lead compounds.In this paper,resorcinol and its derivatives were used to react with ?-keto via Pechmann condensation to produce eleven 7-Hydroxycoumarin analogs.Twenty-eight coumarino[8,7-e][1,3]oxazin derivatives were synthesized from six 7-Hydroxycoumarin analogs and different amines.Twenty-one coumarin Mannich bases were obtained via Mannich reaction from all 7-Hydroxycoumarin analogs and substituted 1,1-diaminome-thanes.The structures of all target products were confirmed by IR,1H-NMR,MS spectrometry,some of them were further confirmed by 13C-NMR.Coumarino[8,7-e][1,3]oxazin derivatives were evaluated in vitro antifungal activities against Botrytis cinrea,Collecterichum capsica,Alternaria solani,G zeae,Rhizoctonia solani and Alternaria mali.The results of preliminary bioassay indicated that the synthesized coumarin derivatives exhibited different levels of antifungal activities to six tested pathogens,especially effective to Rhizoctoniasolani and Botrytis cinerea.Compound 5a displayed the most effective antifungal activity,correspondingly 98.7%,79.6%,69.8%,88.2%against Botrytis cinrea,Collecterichum capsica,G Zeae and Rhizoctonia solani.The EC50 of some active compounds were further tested.