Streptothricin, Streptolin

Streptothricin is a basic peptide, whose formula is C2oHg409Ng (581). It is antibiotic for diverse Gram-positive, Gram-negative, and acid-resistant bacteria (610), and is produced by certain strains of Streptomyces lavendulae (615). The isolation of streptothricin is as follows (455) charcoal adsorption, elution with dilute formic acid, precipitation by picric acid, and conversion of the picrate to hydrochloride, which is then purified by chromatography on either alumina or a mixture of Darco G 60 and paper pulp. The hydrochloride is converted to the crystalline helianthate which possesses a rotatory power Md = — 51.3° (c = 1.4in water). Other salts of streptothricin have been prepared, namely the reineckate (207), picrolonate, flavianate, dipicrate, and sulfate (555,581). According to 

Peterson et al. (457) demonstrated that streptothricin is present in the filtrate of a culture of Streptomyces sp., which also produces streptolin. 

Streptolin is a basic peptide, antibiotic for the same microorganisms as the preceding peptides. It was prepared from an undetermined species of Streptomyces, isolated from the soil by Rivett and Peterson (495), using a technique analogous to that used for streptothrycin, but differing in that precipitation of the peptide was carried out using ether. 

The chemical and antibiotic properties of streptolin are very similar to those of streptothricin and both contain isolysine (530). Streptolin differs in its rotatory power which, for the hydrochloride, is (a]i) = —22° (c = 1.8) and —25° (c = 2.9). It differs also by its adsorption behavior on Filtered, and also by its antibacterial activity, which is 6 times stronger than that of streptothricin in liquid media, but much weaker in an agar culture. This leads to the hypothesis that streptolin is more diffusible than streptothricin. 

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Daniels Structure of the Aminosugar derived from Streptothricin and Streptolin B. J. Amer. chem. Soc. 78, 4817 (1956). 

Group 2 consists of some related compounds possessing unusual amino acids, in addition to the carbohydrate moiety, for example, streptothricin and streptolin. 

Streptothricin D Boseitnycin III. Phytobac-teriomycin D. Racemomycin B. Streptolin A... 

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