Compounds 37-44

turally related to the destomycin family. Spectinomycins (compounds 70-72 ; see pg. 318) are another class in this series that contained actinamine (N,N'-dimethyl-2-epi-streptamine) in their structures.

Acmimycin (72), a spectinomycin analog having a cis-cis ring junction, is believed to have the following structure (see pg. 318) [44].

(b) Streptidine-Containing Aminoglycosides. Streptomycins (compounds 73-78 ; see pg. 319), an important class of aminoglycoside antibiotics, are pseudotrisaccha-rides or pseudotetrasaccharides that contain a 4-substituted streptidine moiety. Streptomycin, a potent chemotherapeutic agent, was the first aminoglycoside antibiotic, discovered in 1944 in the culture filtrate of Streptomyces griseus [7], as described earlier.

Glebomycin [82] is an aminoglycoside antibiotic, that is structurally related to dihydrostreptomycin, having a carbamoyloxy group (NH2COO) instead of the guan-idino group at the 1-position of the streptidine moiety. Antibiotic AC4437 is the de-N-methyl-l-glucosamine analog of dihydrostreptomycin that shows weaker antibacterial activity than dihydrostreptomycin [83].

Ashimycins A and B are two streptomycin analogs (modified in the l-glucos-amine unit) isolated from the fermentation broth of S. griseus [84]. Ashimycin A (compound 79; see pg. 319) carries a glycosidically linked sugar moiety having an

R1 R2 R3

R3 R4 References

45 GentamicinA H NHCH3 OH

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