J. Matějů

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 againstEscherichia coli, 15 of the 17 substances displayed an activity towardBacillus subtilis, Bacillus cereus, Candida albicans, Saccharomyces cerevisiae andStreptomyces aurecfaciens. Relationships between the substance type and biological activity are discussed.

Immunomodulators isolated from microorganisms

Microbial products are surveyed that have an immunoregulatory activity, both from the realm of low-molar-mass compounds and from the group of naturally occurring polymers. The data include in most cases the producer organism or source, a brief chemical characteristic and biological activity. Various groups of substances are compared, the drawbacks attendant on their acquisition and application are pointed out and their advantageous properties are specified.

Studies on the production of daunomycinonederived glycosides and related metabolites inStreptomyces coeruleorubidus andStreptomyces peucetius

Strains ofStreptomyces coeruleorubiduě ISP 5145,JA 10092 and 39–146, differing mutually in antibiotic activity, were found to produce identical spectrum of metabolites (at least nine antibiotically active glycosides, 13-dihydrodaunomycinone, ε-rhodomycinone and a larger number of unidentified compounds); only trace quantities of daunomycin and daunomycinone could be detected. A fraction of glycosides with a higher Rf (0.4–0.7), isolated from strain 39–146, could be transformed to daunomycin by mild hydrolysis and to daunomycinone by total hydrolysis.Streptomyces peucetius IMI 101 335 differed fromStreptomyces coeruleorubidus in an increased production of ε-rhodomycinone and a lower content of glycosides; the zone of daunomycin was most pronounced among the glycoside spots.Streptomyces coeruleorubidus 39-146 exhibited the highest activity in a medium containing 3.5% soluble starch, 3.0% soybean meal, 0.3% NaCl and 0.3% CaCo3; glucose was a more useful carbon source for the remaining strains The activity ofStreptomyces coeruleorubidus was inhibited by 1-propanol, Na-propionate,5,5-diethylbarbiturate and bacitracin. Ferrous sulphate stimulated the production of glycosides only in strain JA 10092, decreasing simultaneously the production of aglycones.

Biotransformations of anthracyclinones inStreptomyces coeruleorubidus andStreptomyces galilaeus

The ability to transform biologically exogenous daunomycinone, 13-dihydrodaunomycinone, aklavinone, 7-deoxyaklavinone, ε-rhodomycinone, ε-isorhodomycinone and ε-pyrromycinone was studied in submerged cultures of the following strains: wildStreptomyces coeruleorubidus JA 10092 (W1) and its improved variants 39–146 and 84–17 (type P1) producing glycosides of daunomycinone and of 13-dihydro-daunomycinone, together with ε-rhodomycinone, 13-dihydrodaunomycinone and 7-deoxy-13-dihydro-daunomycinone; in five mutant types ofS. coeruleorubidus (A, B, C, D, E) blocked in the biosynthesis of glycosides and differing in the production of free anthracyclinones; in the wildStreptomyces galilaeus JA 3043 (W2) and its improved variant G-167 (P2) producing glycosides of ε-pyrromycinone and of aklavinone together with 7-deoxy and bisanhydro derivatives of both aglycones; in two mutant typesS. galilaeus (F and G) blocked in biosynthesis of glycosides and differing in the occurrence of anthracyclinones. The following bioconversions were observed: daunomycinone → 13-dihydrodaunomycinone and 7-deoxy-13-di-hydrodaunomycinone (all strains); 13-dihydrodaunomycinone → 7-deoxy-13-dihydrodaunomycinone (all strains); daunomyeinone or 13-dihydrodaunomycinone → glycosides of daunomyeinone and of 13-dihydrodaunomycinone, identical with metabolites W1 and P1 (type A), or only a single glycoside of daunomyeinone (type E); aklavinone → ε-rhodomycinone (types A and B); aklavinone → 7-deoxyaklavinone and bisan-hydroaklavinone (type C); ε-rhodomycinone → ζ-rhodomycinone (types C, E); ε-rhodomycinone → glycosides of ε-rhodomycinone (types W2, P2); ε-isorhodomycinone → glycosides of ε-isorhodomycinone (types W2, P2); ε-pyrromycinone → a glycoside of ε-pyrromycinone (types W1, P1). 7-Deoxyaklavinone remained intact in all tests. Exogenous daunomyeinone suppressed the biosynthesis of its own glycosidea in W1 and P1; it simultaneously increased the production of ε-rhodomyeinone in P1.

Estimation of lipase activity by the diffusion plate method.

A diffusion plate method for the assay of the activity of lipases in large series of samples was worked out. When using this method the maximum deviation was found to be ±3.8%.

Partial purification and properties of glucosyltransferase fromStreptomyces aureofaciens

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

Isolation of glucosyltransferase fromStreptomyces 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 l-hydroxy-2-(β-D-glueopyranosyloxy)-9,10-anthraquinone.

7-Deoxy-13-dihydrodaunomycinone in cultures ofStreptomyces coeruleorubidus

Abstract7-Deoxy-13-dihydrodaunomycinone was isolated from three strains ofStreptomyces coeruleorubidus. Its production was found to rise at the end of cultivation and to be stimulated by lowered aeration intensity.

Propionate and the production of monensins in Streptomyces cinnamonensis

Variants resistant to propionate wore prepared from a mutant strain ofStreptomyces cinnamonensis producing predominantly monensin A. Using selected resistants the production of monensins (in media with higher concentrations of propionate) was examined. Stimulation of monensin synthesis by propionate. was observed with 70% of the resistants studied. Propionate did not influence the ratio between monensin A and B production.

Microbial Glucosidation of Dihydroxyanthraquinones. General Properties of the Glucosidation System

Corresponding mono-β-d-glucosides were obtained by fermentation ofStreptomyces aureofaciens B 96 with four isomeric dihydroxyanthraquinones (alizarin, quinizarin, chrysazin and anthraflavin). The effect of some factors (sugar source, concentration of substrates, pH) on biosynthesis of 1-hydroxy-2-(β-d-glucopyranosyloxy)anthraquinone was studied and optimum conditions for the microbial glucosidation were determined.