Streptomyces actuosus

Chatterjee and coworkers45 recently reported the taxonomy, production, isolation, structure elucidation and biological properties of a new antibacterial antibiotic alisamycin (75), a new member of the manumycin group of antibiotics obtained by the fermentation of Streptomyces actuosus. 

Alisamycin (48) is a potent antibiotic isolated from Streptomyces actuosus and it also shows weak antifungal and cytotoxic activity [100]. Its structure was established by Chatterjee etal. [101] using spectroscopic methods and the absolute configuration (4R,5S,6R) was determined using the exciton chirality method and CD studies of degradation products [102]. This is the only member of the family which has been synthesized in racemic form [103]. 

C51H43N13O12S6, Mr 1222.38, yellow powder, mp. 310-312°C, a broad spectrum antibiotic produced by streptomycetes (e.g., Streptomyces actuosus), used as a fodder additive for livestock to promote growth. N. is related to thiostrepton. Like the latter, it inhibits protein biosynthesis through binding to the 23S ribosomal RNA and the protein L-11, in this way the GTP hydrolysis activity of the SOS subunit is inhibited. The producer protects itself by methylation of 23S rRNA (host site resistance). 

Smith TM, Priestley ND. Knaggs AR, Nguyen T. Floss HG. 3,4 Dimethylindole-2-carboxy-late and 4-(l hydroxyethy])quinoline-2-carboxvlate activating enzymes from the nosihep-tide and thiostrepton producers, Streptomyces actuosus and Screpiomyces laurenoi. J Chem Soc (Chem Comm) 1993 21 1612-1614. 

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