Compounds isolated at the Department of Biogenesis of Natural Substances, Institute of Microbiology, Czechoslovak Academy of Sciences, in 1984-1988.

A total of 41 compounds studied at the Department of Biogenesis of Natural Substances between 1984 and 1988 are characterized and tabulated. They include natural, semisynthetic and synthetic compounds.

Relationship between the fatty acid composition and the type of antibiotics produced by Streptomyces lasaliensis.

The GC-MS method was used to analyze fatty acids in a parent strain of Streptomyces lasaliensis and its two mutants producing only lasalocid or quinomycin. The biosynthesis of these substances bears relation to differences in the relative proportion of fatty acids. Biosynthetic relationships were revealed between the starter fatty acid units, their precursors, i.

Production of quinomycin A in Streptomyces lasaliensis.

In addition to lasalocid, an oligoether coccidiostatic compound, other compounds are synthesized by Streptomyces lasaliensis. Mutants producing either of two antibiotics, lasalocid A or quinomycin A (an antibiotic of quinoxaline character), were obtained by natural selection and by mutagenesis. Methods of isolation, purification and estimation of both compounds were established.

Very-long-chain fatty acids from lower organism.

The qualitative occurrence and quantitative proportion of very-long-chain fatty acids (above C22), mainly in lower organisms and briefly in higher plants and animals is described.

Regulation of the immune response by ergot alkaloids.

We tested the effect of 33 ergot alkaloids (natural and semisynthetic) on the induction of antibody formation in isolated spleen cells by antigen in tissue cultures. The results are quantitatively expressed as the number of antibody-forming cells. The group of natural ergot alkaloids (ergopeptines) exerted an effective inhibitory action on the antibody response.