Purification of epidermidins, new antibiotics from staphylococci

Antibiotics from the 29297 and 36534 strains of Staphylococcus epiderinidis were purified by treatment with acid and barium hydroxide, followed by precipitation with zinc chloride which separated the active principles into two components. These were designated the zinc-precipitable and zinc-soluble fractions. The use of Dowex and (or) Sephadex G-15 further increased the specific activity of these antibiotics. All fractions of both antibiotics were crystallized from aqueous solutions. Recrystallization and methanol precipitation of the antibiotics brought the specific activity to a relatively constant value. The generic name, epidermidin, is proposed for these antibiotics and 29297 zinc-precipitable and zinc-soluble components are designated epidermidins A 1 and A 2 , while the equivalent 36534 fractions are epidermidins B 1 and B 2 respectively.