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5.
Experientia ; 36(4): 414-6, 1980 Apr 15.
Article in English | MEDLINE | ID: mdl-7379912

ABSTRACT

Nosiheptide (9671 R.P.) isolated from Streptomyces actuosus 40037 (NRRL 2954) is a sulfur-containing polypeptidic antibiotic, quite different from all the other members of this family. Very active in vitro against gram-positive bacteria, it is inactive in vivo in experimentally infected mice. Not toxic, even at high dose, it may be used as a feed additive for chickens and pigs and it shows a favourable effect on the growth and conversion index.


Subject(s)
Anti-Bacterial Agents , Streptomyces/analysis , Animal Feed , Animals , Bacteria/drug effects , Chickens , Drug Evaluation, Preclinical , Food Additives , Spectrometry, Fluorescence , Spectrophotometry, Infrared , Swine , Thiazoles/isolation & purification , Thiazoles/pharmacology
7.
C R Seances Acad Sci D ; 289(5): 473-6, 1979 Sep 24.
Article in French | MEDLINE | ID: mdl-117939

ABSTRACT

From crude extracts of a Streptomyces strain exhibiting immunopotentiating effects, a tetrapeptide was isolated and its structure established as L Ala leads to D isoGlu leads to L, L Dap comes from Gly. This peptide was devoid of biological activity but its chemical coupling with lauric acid gave a substance endowed with adjuvant and immunostimulating properties. This substance and the corresponding synthetic lauroyltetrapeptide were as active in this respect as the muramyl-dipeptide, thus far considered as the minimal adjuvant-active structure of bacterial cell walls: the presence of a sugar moiety is therefore not a prerequisite for immunopotentiating activities.


Subject(s)
Adjuvants, Immunologic , Glycopeptides/immunology , Streptomyces/immunology , Animals , Antibody Formation , Lauric Acids , Mice/immunology , Muramic Acids , Oligopeptides/isolation & purification , Spleen/immunology
8.
Experientia ; 32(3): 319-21, 1976 Mar 15.
Article in English | MEDLINE | ID: mdl-1253897

ABSTRACT

Emericid is a new polyether polycyclic ionophore antibiotic excreted by Streptomyces hygroscopicus (DS 24 367). Active in vitro against Gram-positive bacteria, it is ineffective in vivo. At a 0.006-0.02% level in the diet it protects chickens and rabbits against coccidiosis.


Subject(s)
Anti-Bacterial Agents , Streptomyces/metabolism , Animals , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/therapeutic use , Chemical Phenomena , Chemistry , Chickens , Ethers/biosynthesis , Ionophores/biosynthesis , Microbial Sensitivity Tests , Rabbits
11.
Antimicrob Agents Chemother ; 3(5): 590-8, 1973 May.
Article in English | MEDLINE | ID: mdl-4364180

ABSTRACT

Mengo virus double-stranded ribonucleic acid (dsRNA) was obtained on a semi-industrial scale from infected cultures of BHK-21 cells grown in suspension. Yield of the extraction and purification operations was small (about 22 mg from 10(11) cells in a 100-liter culture). Physicochemical characterization of this dsRNA gave an estimated molecular weight close to 4 x 10(6), a density of 1.59 (similar to that of the poliovirus dsRNA), and a thermal transition midpoint of 94 C. This product was a little more toxic for the mouse, by the intravenous route, than polyriboinosinic . polyribocytidylic acid (poly I:C) and strictly comparable in this respect to poliovirus dsRNA. The interferon-inducing capacity in the mouse and the antiviral activities in the mouse (infected with encephalomyocarditis, Semliki Forest, influenza, foot-and-mouth disease, and murine hepatitis viruses) and in the rabbit (Shope fibroma virus) of the ultraviolet light-inactivated product were practically identical, on a quantitative basis, with those of poly I:C. In vitro and in vivo experiments showed the dsRNA from Mengo virus to be slightly but significantly more resistant than poly I:C to the inactivating effect of human serum.


Subject(s)
Antiviral Agents/pharmacology , Interferon Inducers , Mengovirus , Poly I-C/pharmacology , RNA, Viral , Animals , Female , Mice , Microbial Sensitivity Tests , Rabbits , Virus Cultivation , Viruses/drug effects
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