Cy-FBP/SBPase-IN-1 (compound S5) serves as an inhibitor of the key regulatory enzyme Cy-FBP/SBPase in cyanobacterial photosynthesis, impeding the Calvin cycle and photosystem, thereby reducing photosynthetic efficiency. It effectively suppresses the proliferation of cyanobacteria, including Synechocystis sp. PCC6803, while demonstrating a safe profile in human-derived cell lines and zebrafish models [1].