Metal chelates of streptomycin

Streptomycin has been found to undergo chelation with several metals in aqueous solution. Evidence for chelate formation is provided by a drop in pH during the formation, production of characteristic colors, decreased solubility in water, and absence of metal ions in the solution. The copper chelate, found to be relatively uncontaminated with metal hydroxide, exhibited more prolonged blood levels in guinea pigs than streptomycin sulfate, but also a greater toxicity.