New Sulfoxide Classes And Preliminary Study Of The Filter And Its Mechanism Of Antibacterial Activity Of Quinazoline Compounds

The effect of new quinazoline and sulfoxide derivatives were tested against pathogenic fungi bv using the mycelial growth rate method in the laboratory. Preliminary bioassay tests showed that some compounds possessed good antifungal activities,such as compounds 07115:2-(benzylsulfinyl)-5-(3,4,5-trimethoxyphenyl) -1,3,4-oxadiazole and 07037:4-sulfurbutyl-6-fluoroquinazoline.Further bioassays disclosed that title compounds 07115 and 07037 showed remarkable inhibitory effect on all kinds of the tested plant pathogenic fungi.The EC₅₀ values of 07115 on G.zeae, F.oxysporum,C.mandshurica,R.solani,T.cucumeris,P.infestans,S.sclerotiorum,B. cinerea,C.gloeosporioides ranging from 19.91 to 63.97μg/mL,and the EC₅₀ values of 07037 ranging from 17.47 to 70.79μg/mL.Mechanism of action of compound 07115 against S.sclerotiorum was studied, and Hymexazol(94%W/W) serving as the control.After treating S.Sclerotiorum with compound 07115 at 100μg/mL,most of its hyphal became distorted,malformed and got entangled,the cell of the hypha swelled.And the permeability of the cell membrane increased,the absorption declined.After treatment with compound 07115 for 12 h at 100μg/mL,the mycelial reducing sugar,D-GlcNAc content,soluble protein content,pyruvate content and the chitinase activity showed declining tendency. Only 5.4%of its spore bourgeoned.Mechanism of action of compound 07037 against G.zeae was studied,and Thiophanate methyl(70%W/W) serving as the control.After treating G.zeae with compound 07037 at 100μg/mL,the permeability of the cell membrane increased and most of its hyphal became distorted,short branched,malformed,and its endosome condensed.The absorption declined.After treatment with compound 07037 for 3 h at 100μg/mL,the pyruvate content declined,after treating 12 h the mycelial reducing sugar,D-GlcNAc content,soluble protein content,and the chitinase activity showed declining tendency.Only 6.5%of its spore bourgeoned.