Succinate dehydrogenase-IN-1 (Compound 34) is an inhibitor for succinate dehydrogenase ( SDH ) with an IC 50 of 0.94 μM and a K D of 22.4 μM. Succinate dehydrogenase-IN-1 exhibits antifungal activity against Rhizoctonia solani , Sclerotinia sclerotiorum , Monilinia fructicola , and Botrytis cinerea , with EC 50 of 0.04 μM, 1.13 μM, 1.61 μM and 1.21 μM, respectively.