1. Triglyceride synthesis in rat liver homogenate is stimulated by administration of a single therapeutic dose of tetracycline to the animal prior to sacrifice and maximum stimulation is observed 3 hours after drug-treatment. 2. In the intact tetracycline-treated rat, incorporation of injected 1-14C-palmitate into liver triglyceride reaches its maximum 3 hours after the drug administration. 3. The release of newly synthesized triglyceride from liver to the circulation system seems to be impaired under the influence of the antibiotic treatment. 4. Tetracycline is unable to stimulate triglyceride synthesis in liver homogenate obtained from adrenalectomized rats treated with this antibiotic.
The amino acid composition and molecular weight of phenomycin and degradation studies are reported in this paper. By STEIN-MOORE'S and ultraviolet absorption methods, the molar ratio of amino acids in phenomycin were determined. The N-terminal amino acid is aspartic acid or asparagine.The C-terminal amino acid, determined with carboxypeptidase A and by hydrazinolysis, is tryptophan. The molecular weight is estimated to be about 10, 000 by ARCHIBALD'S method and from the amino acid analysis. The presence of D-amino acids in phenomycin is not certain. Proteolytic enzymes, pepsin, trypsin, chymotrypsin, pronase, nagarse and papain, digest and inactivate phenomycin. One of the fragments obtained by cyanogen bromide cleavage inhibits protein synthesis in a cell-free system of EHRLICH carcinoma cells almost as effectively as phenomycin.
Cirramycin A, a macrolide antibiotic, has been found to consist of one major (A1) and several minor components (A2, A3, A4 and A5). The majoractive substance, cirramycin A1 (C31H51NO10), was isolated as a single component and characterized in detail. It has a strong ultraviolet absorption peak at 241mμ and its chromophore is suggested to be an α, β-unsaturated γ, δ-depoxide carbonyl system. Cirramycin A1 contains the basic sugar mycaminose but lacks a neutral sugar in the molecule.
Cirramycin A1 is primarily active against gram-positive bacteria and exhibits the antimicrobial spectrum typical to that of the macrolide antibiotics. It exerts remarkable activity against a variety of Mycoplasma species. The in vivo activity of cirramycin A1 was evaluated against three gram-positive pathogens, and the absorption and excretion of the antibiotic were studied on rats and dogs.
Monoglycerides and fatty acids with antitumor activity against EHRLICH ascites tumor in mice were isolated from the acetone extract of the mycelium of Sepedonium ampullosporum. In addition, a new Cl- and N-containing antibacterial antibiotic and rugulosin were isolated from this fungus. Rugulosin is a yellow pigment with strong inhibitory activity against Gram-positive bacteria and Proteus vulgaris.
Substances with antitumor activity isolated from Sepedonium ampullosporum, Cercospora oryzae and Coriolus unicolor were chemically and spectrometrically studied. They were identified as the mixtures of 1-monoglycerides, having octadecenoic and octadecadienoic acids with or without hexadecanoic acid as the main components. They contain other fatty acids with larger and smaller carbon numbers as the minor components. Fatty acid composition of the monoglycerides depends upon the origin of the glycerides.