Effects of SSF-126, a novel alkoxyiminoacetamide blasticide, on mycelial growth and oxygen consumption of Pyricularia oryzae

SSF-126, (E)-2-methoxyimino-N-methyl-2-(2-phenoxyphenyl)acetamide, inhibited mycelial growth (IC 50 7.7 μM) of Pyricularia oryzae. The inhibited mycelium, which was incubated for 30h in the presence of SSF-126, grew vigorously after transfer to a fungicide-free medium, indicating that SSF-126 is a fungistatic compound. SSF-126 strongly inhibited oxygen consumption by P. oryzae at low concentrations (IC 50 0.8 μM). However, the initial inhibition of oxygen consumption was followed by normal mycelial respiration that was insensitive to SSF-126. These results suggest that SSF-126 has a new type of antifungal action.