Eckol is a phlorotannin isolated from brown algae in the family Lessoniaceae such as species in the genus Ecklonia[1] such as E. cava[2] or E. kurome[3] or in the genus Eisenia such as Eisenia bicyclis.

[4] The molecule possesses a dibenzo-p-dioxin skeleton and a phloroglucinol component.

The molecule can also be viewed as a phloroglucinol trimer.

[1][6] It also exhibits an in vitro cytoprotective effect against oxidative stress in Chinese hamster lung fibroblasts.

[2] It also shows antithrombotic and profibrinolytic activities.