Ophiobolin D
Ophiobolin B, a sesterterpene metabolite of Helminthosporium oryzae, inhibits proton extrusion from maize coleoptiles. Ophiobolin B inhibits fusicoccin (FC) promoted proton extrusion, potassium uptake and cell enlargement[1]. The MIC values with the antifungal effect of Ophiobolins B on different zygomycetes is 25–50 μg/mL[2].