Production of anticapsin by Streptomyces griseoplanus

Anticapsin is a new fermentation product which inhibits formation of the hyaluronic acid capsule of Streptococcus pyogenes. Production of this metabolite in a complex medium by S. griseoplanus is enhanced by high levels of carbohydrate. A number of carbon sources support biosynthesis but sucrose is most effective, the optimum level being 150 g/liter. Neither glucose nor fructose, alone or in combination, serves as an equivalent substitute for sucrose. The addition of dibasic potassium phosphate to the medium further increases anticapsin production. Dissolved oxygen levels are important for synthesis and stability of the metabolite. Anticapsular activity diminishes rapidly in previously aerated broths which are held under static conditions. This decrease does not occur in pasteurized broths or unpasteurized filtrates.

The structure of anticapsin, a new biologically active metabolite of Streptomyces griseoplanus

1. Physical and analytical data obtained on crystalline anticapsin indicated the empirical formula C(9)H(13)NO(4). Spectral data (u.v., i.r. and proton magnetic resonance) and formation of l-tyrosine on hydrolysis revealed the functionalities and carbon skeleton of the new epoxy keto amino acid. 2. The optical properties of anticapsin (optical rotatory dispersion and circular dichroism) permitted assignment of absolute configuration to the new metabolite. 3. Treatment of anticapsin with hot methanolic hydrochloric acid followed by acetylation gave C(18)H(19)NO(5), the alpha-alkoxycyclohexenone derivative. Analysis of the nuclear-magnetic-resonance and mass spectra of the latter allowed its structure to be determined and confirmed the assigned structure of anticapsin.