Streptomycin guanidino group

Streptomycin gave a positive Sakaguchi test and this evidence for the presence of the guanidino group was supported by the fact that alkaline hydrolysis resulted in the formation of ammonia and the disappearance of the test. Two guanidino groups were indicated since only one of the... 

A study of streptomycin using N and n.m.r. indicates that the streptose formyl group does not cyclize with either methylamino- or guanidino-groups in the other rings giving a four-ring structure, but is probably hydrated. ... 

That the aldehydo-group of streptomycin does not cyclize with either the methylamino- or the guanidino-groups to form a four-ring structure has been shown by n.m.r. spectroscopy. Instead it is suggested that the group is probably hydrated and stabilized by the C-3 hydroxy-group of L-streptose, ... 

Streptomycin was the first of the class of aminoglycoside antibiotics to be discovered in 1943. Isolated from Streptomyces griseus, it was the first antibiotic remedy for tuberculosis. Streptomycin, also known as streptomycin A, is an oligosaccharide with basic properties. Like other representatives of the aminoglycoside family, it consists of a monosaccharide, an amino sugar, and a guanidino-substituted cyclohexane with at least three hydroxide groups. 

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