Heneicomycin, a new antibiotic (A21A): fermentation, isolation, and antibacterial spectrum.

In the course of our screening for new antibiotics, we have found heneicomycin (antibiotic A21A)1) in culture broth of a newly isolated strain of Streptomyces filipinensis, designated NRRL #11044 (MA-4581 in the Merck & Co., Inc. culture collection). From the physico-chemical and biological properties described in this communication, heneicomycin is considered to be equivalent to 3-deoxyaurodox (Fig. 1), a new antibiotic belonging to the aurodox (X5108)2) kirromycin3) group. Heneicomycin, which is active in vitro vs both Gram-positive and Gram-negative organisms (Table 1), is produced by cultivating S. ftlipinensis NRRL 11044 under submerged, aerobic conditions in aqueous medium containing 4 % tomato paste and 1.5% ground oatmeal, with pH adjusted to 6.0 with NaOH. Production of the antibiotic reached a maximum after 5 days' incubation at 28°C on a rotary shaker at 220 rpm. The culture broth containing heneicomycin was filtered through Celite and the filtrate was adjusted to pH 5.0 with hydrochloric acid before extraction with ethyl acetate. The ethyl acetate extract was triturated with n-hexane thereby precipitating heneicomycin. The resulting precipitate was subjected to preparative silica-gel thin-layer chromatography using chloroform, methanol, and concentrated aqueous NH3 (80: 20: 1.5) as a developing solvent. The major band, which was bright yellow in color, was extracted with a mixture of chloroform, methanol, and distilled water (60: 30: 3). The solution was concentrated, redissolved in benzene methanol (95: 5) and lyophilized, yielding heneicomycin as an amorphous bright yellow powder which was soluble in methanol and ethanol and slightly soluble in chloroform and acetone. HeneicomyFig. 1. Structure of heneicomycin. Table 1. Antibacterial spectrum of antibiotic A21A.