TWO ANTIBIOTICS (LAVENDULIN AND ACTINORUBIN) PRODUCED BY TWO STRAINS OF ACTINOMYCES: II. PURIFICATION AND ISOLATION

Abstract

This paper describes the purification of two antibiotic substances produced by strains of Actinomyces isolated from soil. Both organisms were isolated and studied by Dr. Albert Iielner of the University of Pennsylvania for their cultural characteristics and conditions for maximum production of the antibiotic substances. Animal experiments, determination of antibacterial spectrum, etc., were conducted by Dr. Harry E. Morton, also of the University of Pennsylvania (l-3). One strain of Actinomyces, designated as A-10 in earlier work, resembles Actinomyces lavendulae, and the antibacterial substance produced by it has been called lavendulin (2). The other strain of Actinomyces, originally designated as A-105, resembles in some respects Actinomyces erythreus, A. jradii, A. albosporeus, and A. calijornicus, and the antibacterial substance produced by it has been called actinorubin (2). Under suitable conditions of growth both strains of Actinomyces produce antibacterial substances which are active against both Gram-positive and Gram-negative microorganisms. Purification of the antibiotics is achieved by the same method. The antibiotic principle is adsorbed on a cation exchanger (notably Decalso) and eluted with saturated NaCl. The NaCl eluate containing the active principle is evaporated to dryness and extracted with boiling methanol. The methanol extract is precipitated with half its volume of ether, the supernatant discarded, and the precipitate washed with absolute ethanol. The resulting dried powder is the partially purified antibiotic. Most of the animal and toxicity experiments conducted by Dr. Morton were carried out with these preparations. The final purification of the antibiotics is accomplished through chromatographic adsorption on activated aluminum oxide in 85 per cent methanol. Certain fractions of the chromatogram containing the hydrochlorides of lavendulin (strain A-10) and actinorubin (strain A-105) form insoluble addition compounds with methyl orange, which are recrystallized from methanol-water mixtures.