Biological Properties of Antibacterial Substances

Actibomycin. Actinomycin A (164,170), CM-nHia-ssNT-sOs-in m.p. 250 C., red platelets, [ ]b — —320°, absorption peaks at 2400 and 4500 A soluble in acetone, alcohol, benzene, 10% hydrochloric acid slightly soluble in water and ether insoluble in dilute acids, dilute alkalies, and petroleum ether. It is readily reduced by sodium hydrosulfite and by stannous chloride but not by sodium bisulfite. Several groups can be acetylated. It seems to be a quinone containing free hydroxyl groups. Oxford (120) thinks that it may not be a true para quinone and that it might contain a polypeptide chain, like gramicidin, as well as a chromo- 

Altium sativum. The compound, C.Hi OS2(CaH,SOSCaHj) (41,47), a colorless oil, djo 1.112, 1.651, optically inactive, only end absorption 

Asarum canadense. Product B (42), CuHnOiN, does not melt, darkens slowly 230°C., lemon-yellow needles, absorption peaks at 2500, 3180, 3900 A, acidic substance soluble in ethanol, acetone, chloroform, ethyl acetate, and dioxane almost insoluble in water, benzene, and petroleum ether. The salts are soluble in water. Product B is stable at pH 10. It is inactivated by cysteine. It was isolated from the leaves and stems of Asarum canadense var. reflexum (wild ginger) in a yield of about 20 mg. per kg. of fresh leaves and stems. It has low activity against Grampositive bacteria only. Toxicity was not determined. 

Chaetomin, Chaetomin (79,162), CHONS (empirical formula unknown), not crystalline, m.p. 218-220°C. dec., neutral substance soluble in acetone, ethyl acetate, chloroform, and benzene less soluble in ether and alcohol insoluble in water and petroleum ether. Chaetomin can be heated in water to 100°C. for ten minutes. It is stable in alcoholic solution and in 0.01 N hydrochloric acid at room temperature for 24 hours. It is destroyed in 24 hours at room temperature by 5% sodium carbonate solution. Chaetomin is produced by Chaetomium cochliodes grown on Czapek-Dox and corn-steep media in static and shaken cultures. Most (95%) of the chaetomin is found in the mycelium. A liter of culture fluid may yield 

The titer was decreased about half for a hundred-fold increase in concentration of bacteria in the test. Semiquantitative antibacterial activity in gramma per milliliter is given below  

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