Gentamicin C1 Sulfate, EvoPure® is composed of ≥95.0% Gentamicin C1. Gentamicin C1 makes up 25-50% of Gentamicin depending on the manufacturer or manufacturing process. Gentamicin C1 Sulfate is part of the Gentamicin C complex (Gentamicin C1, Gentamicin C1a, and Gentamicin C2). Gentamicin C1 differs from Gentamicin C1a by a methyl group in the 6’ position of the purpurosamine (2-amino-hexose) ring. The complex accounts for approximately 80% standard grade Gentamicin and has the most potent antimicrobial activity, thought to be due to the lack of hydroxy groups on the 3’ and 4’ positions of the purpurosamine (2-amino-hexose) fragments.