Study On The Relationship Between Chemical Structure Of Phenols And Its Chemically Modified Compounds And Antifungal Activity

The tests on effects of phenols and their derivatives were conducted on Rhizopus stolonifer,Fusarium semitecum,A hernaria alternata .The relationship between chemical structure of phenolic compounds and antifungal activity was analysed. The mechanism of antifungal was discussed. These results showed that: (1 )p-polyhydroxyphenolic,opolyhydroxyphenolic(pyrocatechal,hydroquinone,pyrogallol) had better effect than phenol,m-polyhydroxy phenolic(resoricinol ,phloroglucinnol) was the least effect.(2) After one of hydroxyl group of pyrocatedchol and hydroquinone was substituted for carboxyl group , They were greatly less effective against these fungal.(3)After P-hydroxy benzoic acid was esterificated,the antifungal efficiency of it was obviously increased,but salicylic acid had not the same effect .They showed the strongest inhibitory effect when the length of esterification alkyl reached 5-6 carbon atoms.When the number of the carbon atoms exceeded 7(c~7)their antifungal efficiency were rather worse.p-hydroxy benzoic acids esters had l~etter effective against the fungal than o-hydroxy benzoic acid esters .After phenol and polyhydroxy phenolic were esterificated,the effect were worse except. M-polyhydroxy phenolic (4) Rhizopus stolorn抐er,Fusarium semitecum were able to produce PG,PME,cellulase in medium.It was found that the CWDE activity(PG,PME,cellulase) produced by the two pathogens was higher inmedium containing 1% pectin than in medium containing 1%CMC.Pectin were able to make the two pathogens produce more PG,PME than CMC.(5) 2Omg/L hydroquinone,Buty-p-hydroxy benzoate respectively inhibit FusariumsemitecumRhizopusstolonifertoproduceCWDE(PG,PME,cellulase)(6)Hexyl-p-hydroxy benzoate could contro~ soft rot by Fusarium semitecum and Rhizopus stolonifer,and Heptylic-p-hydroxy benzoate could control soft rot by Alternaria alternata.