Streptomycin drug molecule. Ball-and-stick molecular model of streptomycin, an aminoglycoside antibiotic. It was the first of the aminoglycoside class of antibiotics to be discovered, and was the first effective treatment for tuberculosis. It is derived from the actinobacterium Streptomyces griseus, and is able to kill bacteria via inhibiting their ability to synthesise proteins. Its chemical formula is C21H39N7O12. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (black), oxygen (red), and nitrogen (blue).