Galegine

Galegine is a toxic chemical compound that has been isolated from Goat's rue ("Galega officinalis"). It has also been found to be the principal cause of the toxicity of poison sedge ("Schoenus asperocarpus").
Galegine was used in the 1920s as a pharmaceutical treatment for diabetes; however, because of its toxicity, its use was soon supplanted by superior alternatives. Research based upon the effects of galegine eventually led to the development of metformin which is used today for treatment of type 2 diabetes.