Isorhamnetin 3-sophoroside-7-rhamnoside is a natural flavonol glycoside. Isorhamnetin 3-sophoroside-7-rhamnoside inhibited the growth of harmful microalgae. Isorhamnetin 3-sophoroside-7-rhamnoside is closely related to the convergence of different fruit pups, which is less affected by some known convergent compounds.