Cyanobacteria harmful algal blooms (HABs) pose an increasingly serious water pollution problem all over the world.Class Ⅱ Fructose-l,6-bisphoshate aldolase (Cy-FBA-Ⅱ) and cyanobacteria Fructose-l,6-Bisphosphatase (Cy-FBPase) are two neighbouring key regulatory enzymes in Calvin cycle of cyanobacteria photosynthesis system.Each of them might be taken as the potential target for designing novel inhibitors to chemically control harmful algal blooms (HABs).In the present paper, a series of novel inhibitors were designed, synthesized and optim...