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.e. valine, leucine and isoleucine, and the type of the antibiotic produced.

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.

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.

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. Compounds derived from lysergic acid are completely inactive in this respect. A new, very active semisynthetic drug (Table 1, compounds 2) derived from inactive lysergol was described. The compounds interacting with alpha-adrenergic-receptors on lymphocytes (methoxamine, phentolamine, prazosin act synergistically with the inhibitory effect of ergopeptine alkaloids.

Compounds isolated at the Department of Biogenesis of Natural Substances, Institute of Microbiology, Czechoslovak Academy of Sciences, in 1954-1983.

Substances studied at this department in 1954-1983 are reviewed; a total of 226 compounds are characterized in a tabular form. They include natural compounds as well as those prepared by biotransformation, by semisynthetic and synthetic methods.

Microbial glucosidation of 1,2,4-trihydroxy-9,10-anthraquinone (purpurin).

Streptomyces aureofaciens glucosidizes 1,2,4-trihydroxy-9,10-anthraquinone (purpurin) added to the cultivation medium to yield the corresponding 2-beta-D-glucoside. The identity of the glucoside was demonstrated by comparing its physico-chemical properties with data of an authentic sample prepared synthetically. A further chemical glucosidation of the acetylated 2-beta-D-glucoside gives rise to 2-(hepta-O-acetyl-beta-gentiobiosyl)-4-(tetra-O-acetyl-beta-D-gluc opyranosyl) purpurin. All the derivatives are immunoactive.

Effect of colchicine derivatives on the antibody response induced in vitro.

Effect of 44 colchicine derivatives on the induction of antibody response in tissue cultures was tested. Lymphatic cells from the spleen of BALB/c mice were cultivated with antigen (sheep red blood cells) and the number of antibody forming cells was determined by the plaque technique. Most compounds with the immunoinhibitory effect are derived from the colchicine formula (I). The effect was increased by introducing ethyl, formyl or methylenedioxide groups. Colchinols exerted very good immunoinhibitory effect resulting by contraction of tropolone ring C into the aromatic one. A complete loss of the effectivity was detected in the case of glucoside of colchicine, colchiceine, isocolchicine, oxycolchicine, allocolchicine and in lumiderivatives of colchicine. No correlations between the immunoinhibitory effect, toxicity and stathmokinetic effect were detected: decrease of cell viability and arrest of mitoses were not observed in cultured lymphocytes within the range of the immunoinhibitory effect. The effect of colchicine derivatives was manifested as the inhibition of lymphocyte blastogenesis, which is probably the result of membrane transport blockade.

The immunoinhibitory and immunostimulatory effects of hydroxyanthra- and hydroxynaphthoquinone derivatives.

The immunostimulatory and immunoinhibitory effects of 44 hydroxyanthra- and hydroxynaphthoquinone derivatives in tissue culture were investigated. In the test system used, the final effect, i.e. production of antibodies against sheep red blood cells is a result of cooperation between macrophages, T lymphocytes and B lymphocytes. It was found when testing selected 20 derivatives that methylation, acetylation or substitution of the hydroxy group by the amino group led to the loss of the inhibitory activity and, on the contrary, pronounced immunostimulatory effects could be observed in other derivatives. Naphthoquinones (juglone, lawsone) were more effective as immunoinhibitors than anthraquinones (alizarin, quinizarin) and their derivatives. In both groups of compounds glucosidation results in a substantial increase of the immunoinhibitory effect. The present work is a part of a more extensive study concerning modification of the molecules of various compounds and its relationship with the effect on immunological reactions.

Partial purification and properties of glucosyltransferase from Streptomyces aureofaciens.

Differential centrifugation, precipitation with ammonium sulphate and chromatography on DEAE-cellulose led to a twenty-fold purification of glucosyltransferase from Streptomyces aureofaciens B 96. The Michaelis constants for glucosyluridyl diphosphate (UDP-glucose) was 10.8 microM for 1,2-dihydroxy-9,10-anthraquinone (alizarin) 110 microM; the maximum rate of glucosylation reaction was 5.32 mumol per s per mg protein. The pH optimum was at 7.1; the flat temperature optimum was at 30 degrees C. Using some hydroxy derivatives of 9,10-anthraquinone it was found that the production of glucosides from aglycones with alpha-hydroxyl groups was about 1/8 of the values obtained with beta-hydroxyl substrates. In both types of aglycones the presence of another hydroxyl group led to a higher glucoside production.

Isolation of glucosyltransferase from Streptomyces aureofaciens.

Streptomyces aureofaciens B 96 grown on a synthetic medium glucosylated exogenous 1,2-dihydroxy-9,10-anthraquinone (alizarin). The glucosylation was inhibited by 2,4-dinitrophenol added to the cultivation medium. A cell-free preparation was obtained from the mycelium isolated after 16 h of growth and was found to catalyze the transfer of glucose from glucosyluridyl diphosphate to 1,2-dihydroxy-9,10-anthraquinone, giving rise to 1-hydroxy-2-(beta-D-glucopyranosyloxy)-9,10-anthraquinone.

Antitumour and immunosuppressive activity of hydroxyanthraquinones and their glucosides.

Both isomeric monohydroxyanthraquinones (1a, b), three dihydroxyanthraquinones (alizarin 1c, chrysazin 1d, and anthraflavin 1e) and corresponding acetylated (2) and free (3) beta-D-glucosides were screened for antitumour and immunosuppressive activity. Furthermore, four O-acetyl and O-benzyl derivatives of alizarin (5a--d) were tested. Antitumour activity was judged by the inhibition of growth of syngeneic tumours in the treated recipients and immunosuppressive activity by the effect on tumour growth or on skin graft survival in pretreated allogeneic recipients; as standard of reference served the activity of certain cancerostatic or immunosuppressive drugs used in clinical practice. 1-Hydroxyanthraquinone (1a), alizarin (1c), chrysazin (1d), acetylated glucoside of 2-hydroxyanthraquinone (2b), 2-benzylalizarin (5c), and 1-acetyl-2-benzylalizarin (5d) were found to exhibit antitumour activity. Distinct immunosuppressive activity was detected in alizarin (1c), acetylated glucoside of 1-hydroxyanthraquinone (2a), acetylated glucoside of 2-hydroxyanthraquinone (2b), acetylated glucoside of chrysazin (2d), 2-acetylalizarin (5a), and 1-acetyl-2-benzylalizarin (5d). The group of hydroxyanthraquinone glucodises (3a--3d) exhibited neither antitumour nor immunosuppressive activity.

Biological activity of hydroxyanthraquinones and their glucosides toward microorganisms.

Five mono- and dihydroxyanthraquinones as well as 12 of their glucosides (both free and acetylated) were tested with six different microbial species using the plate-diffusion method. None of the tested substances was active against Escherichia coli, 15 of the 17 substances displayed an activity toward Bacillus subtilis, Bacillus cereus, Candida albicans, Saccharomyces cerevisiae and Streptomyces aureofaciens. Relationships between the substance type and biological activity are discussed.