Effect of synthetic analogues of strobilurin A on the growth of fungi which damage papery materials

The inhibiting effect of some new synthetic analogues of strobilurin A on the germination of conidia or spores and the fungal growth of different fungal strains, which have been isolated from deteriorated papers, have been evaluated. The fungal strains investigated were: Penicillium chrysogenum Them, Stachybotrys atra Corda, Chaetomium elatum Kunze and Aspergillus terreus Them. The compounds tested were: methyl (E)-2-(2-phenoxyphenyl)-3-methoxypropenoate, (E)-1; methyl (E)-2-(naphtyl)-3-methoxypropenoate, (E)-2; methyl (E)2-(4-chlorophenyl)-3-methoxypropenoate, (E)-3; methyl (E)-(2-methylphenyl)-3-methoxypropenoate, (E)-4; methyl (E)-2-[2-(6-methoxy-2-naphthyl)-1-cyclopentenyl]3-methoxypropenoate, (E)-5 and methyl (E)-2-[(E)-2-phenylethenyl-1-cyclopentenyl]-3-methoxypropenoate, (E)-6. All these compounds were tested at concentrations as low as 0.5x10(-4) M for 12, 24, 72h until 10 days of incubation at 27 degrees C and the effect of these substances was measured as % of germination inhibition of conidia or spores ("in vitro" experiments). In a second series of experiments the compounds were tested on germinated conidia or spores and the effect of these substances was determined by evaluation of the ergosterol content. In both series of experiments compounds (E)-1 and (E)-3 proved to be the most effective in inhibiting the germination of conidia or spores as well as the fungal growth in all the fungal strains. Similar results were obtained in "in vivo" experiments where the effect of the compounds on the fungal growth was evaluated for 20 days on paper strips incubated at 27 degrees C and 85% relative humidity.