Biomedical subjects
Publications and source records attributed to J Matĕjů.
Alizarin glucosyl transferase activity was found in five mutant strains of Streptomyces aureofaciens. The activity bears no direct relationship to the final products of tetracycline biosynthesis.
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.
Mycelium of Streptomyces cinnamonensis mutant strains cultivated in a synthetic medium with glycine produced protoplasts after lysis of cell walls with lysozyme. The protoplast yield was up to 95%. The protoplasts could revert and mycelial forms were thus regenerated. In a sucrose-containing medium the protoplasts stored at 4 degrees C were stable for 2 d.
Analytical and preparative high-performance liquid chromatography of 3 phenazines and furonaphthoquinone derivative on reversed-phase column are described. The mobile phase was methanol and water. The injected amount of the mixture was about 30 mg for a preparative chromatographic run requiring 80 min. Substances were detected directly in the column effluent by UV detection.
Vitamins added to submerged Streptomyces cinnamonensis cultures stimulated the production of monensins. Vitamins B2, B3, B5 and B12 enhanced the production by about 50%, vitamins B1 and B6 by 100%. The addition of biotin in optimal concentration resulted in more than 3-fold increase in total production.
Variants resistant to propionate were prepared from a mutant strain of Streptomyces 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.
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.
The ability to transorm biologically exogenous daunomycinone, 13-dihydrodaunomycinone, aklavinone, 7-deoxyaklavinone, epsilon-rhodomycinone, epsilon-isorhodomycinone and epsilon-pyrromycinone was studied in submerged cultures of the following strains: wild Streptomyces coeruleorubidus JA 10092 (W1) and its improved variants 39-146 and 84-17 (type P1) producing glycosides of daunomycinone and of 13-dihydrodaunomycinone, together with epsilon-rhodomycinone, 13-dihydrodaunomycinone and 7-deoxy-13-dihydrodaunomycinone; in five mutant types of S. coeruleorubidus (A, B, C, D, E) blocked in the biosynthesis of glycosides and differing in the production of free anthracyclinones; in the wild Streptomyces galilaeus JA 3043 (W2) and its improved variant G-167 (P2) producing glycosides of epsilon-pyrromycinone and of aklavinone together with 7-deoxy and bisanhydro derivatives of both aglycones; in two mutant types S. galilaeus (F and G) blocked in biosynthesis of glycosides and differing in the occurrence of anthracyclinones. The following bioconversions were observed: daunomycinone leads to 13-dihydrodaunomycinone and 7-deoxy-13-dihydrodaunomycinone (all strains); 13-dihydrodaunomycinone leads to 7-deoxy-13-dihydrodaunomycinone (all strains); daunomycinone or 13-dihydrodaunomycinone leads to glycosides of daunomycinone and of 13-dihydrodaunomycinone, identical with metabolites W1 and P1 (type A), or only a single glycoside of daunomycinone (type E); aklavinone leads to epsilon-rhodomycinone (types A and B); aklaviinone leads to 7-deoxyaklavinone and bisanhydroaklavinone (type C); epsilon-rhodomycinone leads to zeta-rhodomycinone (types C, E); epsilon-rhodomycinone leads to glycosides of epsilon-rhodomycinone (types W2, P2); epsilon-isorhodomycinone leads to glycosides of epsilon-isorhodomycinone (types W2, P2); epsilon-pyrromycinone leads to a glycoside of epsilon-pyrromycinone (types W1, P1). 7-Deoxyaklavinone remained intact in all tests. Exogenous daunomycinone suppressed the biosynthesis of its own glycosides in W1 and P1; it simultaneously increased the production of epsilon-rhodomycinone in P1.
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.
7-Deoxy-13-dihydrodaunomycinone was isolated from three strains of Streptomyces coeruleorubidus. Its production was found to rise at the end of cultivation and to be stimulated by lowered aeration intensity.
Strains of Streptomyces coeruleorubidus 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, epsilon-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 from Streptomyces coeruleorubidus in an increased production of epsilon-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 of Streptomyces coeruleoribidus 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.
Daunomycinone, aglycone of the anthracycline antibiotic daunomycin, was transformed by a washed mycelia of Streptomyces aureofaciens B-96 in a buffer solution containing sucrose; the obtained product, dihydrodaunomycinone (9-(1-hydroxyethyl)-7,8,9,10-tetrahydro-6,7,9,11-tetrahydroxy-4-methoxy-5,12-naphthacenequinone), was identified by measuring basic physicochemical characteristics (IR, UV and visible spectra, mass spectra and NMR, optical rotation and m.p.).
Explore the source record for details and available documents.