SYNTHESIS, FUNGICIDAL ACTIVITY, AND EFFECTS ON FUNGAL POLYAMINE METABOLISM OF NOVEL CYCLIC DIAMINES

A number of novel, cyclic diamines were synthesized and examined for f ungicidal activity as part of a continuing program of work on polyamin e analogues. The novel synthetic cyclic diamines trans-1,2-bis(diethyl aminomethyl)cyclopentane (compound 1) and ants-5,6-bis(aminomethyl)bic yclo[2.2.1]-hept-2-ene (compound 2) and the synthetic cyclic diamine m ethylaminomethyl)-4,5-dimethylcyclohexa-1,4-diene (compound 3) control led the important crop pathogen Erysiphe graminis DC f.sp. hordei Marc hal. Since E. graminis cannot be cultured in vitro, the effects of the three diamines on polyamine biosynthesis were studied using the funga l pathogen Pyrenophora avenae Ito & Kuribay. All three compounds were effective in reducing the growth of P. avenae in vitro and in altering polyamine levels. However, whereas compound 1 reduced concentrations of all three polyamines, compound 2 increased spermidine 2-fold and co mpound 3 had little effect on spermidine and spermine concentrations b ut reduced putrescine concentration by 69%. These changes in polyamine concentrations could not be correlated with changes in activities of biosynthetic enzymes. It seems therefore that although these novel cyc lic diamines alter fungal polyamine metabolism, their effects on the g rowth of P. avenae may not be related to depletion of cellular polyami nes.