SDH-IN-2, a potent succinate dehydrogenase (SDH) inhibitor with an IC50 of 0.55 μg/mL, demonstrates antifungal activity against plant pathogenic fungi, with EC50 values ranging from 3.82 to 9.81 μg/mL.

SDH-IN-2 (Compound 13) (200 μg/mL; 7 days) completely inhibited Physalospora piricola infection in apples and demonstrated a high inhibition rate of 70.9-86.9% against all fungi even at 20 μg/mL.[1] The EC50 values for inhibiting P. oryza and F. oxysporum f. sp. niveum were 4.33 and 3.56 μg/mL, respectively.[1] SDH-IN-2 (0-50 μg/mL) showed no effect on bean seed germination rate, and SDH-IN-2 (0-100 μg/mL) had no significant effect on the growth of wheat seedlings.[1] The compound inhibits SDH enzyme activity with an IC50 of 0.55 μg/mL and binds well to the ubiquinone binding region of SDH through hydrogen bonds, forming π-alkyl and π-cation interactions.[1] SDH-IN-2 (0-200 μg/mL; 7 days) inhibits P. piricola infection on apples.[1]