Kedarcidin, a new chromoprotein antitumor antibiotic. I. Taxonomy of producing organism, fermentation and biological activity.

Strain L585-6 (ATCC 53650) is an actinomycete isolated from a soil sample collected in Maharastra State, India. It produces a new chromoprotein antitumor antibiotic, designated kedarcidin. Taxonomic studies demonstrated that strain L585-6 is an unidentified and unknown actinomycete. Kedarcidin shows potent antitumor activity against implanted P388 leukemia (3.3 micrograms/ml/kg) and B16 melanoma (2 micrograms/kg) in mice. Kedarcidin also shows potent antimicrobial activity against Gram-positive bacteria but no activity against Gram-negative bacteria.

Tetrazomine, a new antibiotic produced by an actinomycete strain. Taxonomy, fermentation, isolation and characterization.

A new antibacterial antibiotic tetrazomine was found from the fermentation broth of an actinomycete strain which was isolated from beach sand collected at Chichijima, Ogasawara Islands, Tokyo, Japan. The strain Y-09194L, was identified as Saccharothrix mutabilis subsp. chichijimaensis subsp. nov. The antibiotic exhibited broad antimicrobial activity against Gram-positive and Gram-negative bacteria in vitro. It also exhibited strong cytotoxic activity against P388 leukemia cells and showed antitumor activity against P388 leukemia. The apparent molecular formula of tetrazomine was determined as C24H34N4O5. It has a rare structure which consists of six rings including piperidine, piperadine, oxazole, and pyrrolidine.

Artritis de rodilla por Streptomyces Somaliensis: un caso / Arthritis of knee for streptomyces somaliensis: a case

Se presenta un caso de artritis de rodilla por Streptomyces somaliensis, raro agente causal de micetomas, que predomina en el continente africano. Es el segundo caso encontrado en la Argentina, con aislamiento e identificación microbiológica del agente causal y el único donde se demostró compromiso intra-articular

Isolation of cytotoxic substance, kalafungin from an alkalophilic actinomycete, Nocardiopsis dassonvillei subsp. prasina.

An alkalophilic actinomycete, strain OPC-553 regarded as Nocardiopsis dassonvillei subsp. prasina, produced the cytotoxic substance, TS-1, which showed a marked inhibitory activity against L5178Y mouse leukemic cell in vitro. The cytotoxicity of TS-1 on this cell was very strong and its ID50 was 0.018 micrograms/ml. Through direct comparison of its spectral data with those of an authentic sample, TS-1 was identified as the antifungal antibiotic, kalafungin, already isolated from the culture broth of Streptomyces tanashiensis. However, the isolation of kalafungin from an alkalophilic actinomycete and its cytotoxicity are reported for the first time in this paper.

Ansamitocin P-3, a maytansinoid, from Claopodium crispifolium and Anomodon attenuatus or associated actinomycetes.

Guided by cytotoxicity, ansamitocin P-3, a maytansinoid, was isolated in very low yield from two members of the moss family Thuidiaceae, Claopodium crispifolium (Hook.) Ren. & Card. and Anomodon attenuatus (Hedw.) Hueb. Ansamitocin P-3 showed potent cytotoxicity against the human solid tumor cell lines A-549, HT-29. A possible basis for the occurrence of this compound in mosses is discussed.

Taxonomic studies on Kitasatosporia cystarginea sp. nov., which produces a new antifungal antibiotic cystargin.

Taxonomic studies on a new species, Kitasatosporia cystarginea are presented. Among the several species already described in this genus, this strain is characteristic in forming distinct spirals of spore chains. A significant properties of the species is the production of a new antifungal antibiotic, cystargin.

Rapid screening method for inhibitors of protein kinase C.

Specific inhibitors of protein kinase C (PKC) were screened for with a unique detection system, named bleb forming assay. When K562, a human chronic myeloid leukemia cell, was treated with phorbol 12,13-dibutylate (PDBu) or teleocidin which are activators of PKC, many blebs appeared on the cell surface of K562 within 10 minutes. This appearance of blebs is inhibited by staurosporine and H7 which are known to be PKC inhibitors. Teleocidin and PDBu did not induce bleb formation of HL60, a human acute promyelocytic leukemia cell, and the mouse Friend leukemia cell, even though their morphology was changed 24 hours after treatment with teleocidin or PDBu. Many inducers of terminal differentiation of K562 have the same effect on HL60 and Friend cells. However, the bleb inducing activity of PKC activators seems to be specific for K562. The bleb forming assay satisfied the criteria (simplicity and specificity) required for preliminary screening of activators or inhibitors of PKC. Teleocidins A and B, and tautomycin (a new antibiotic isolated in our laboratory) were identified as activators of PKC, and also staurosporine and isoflavones (daidzein and genistein) as inhibitors.

A new immunomodulator, FR-900494: taxonomy, fermentation, isolation, and physico-chemical and biological characteristics.

FR-900494 is a new type of immunoactive substances produced by an actinomycete named Kitasatosporia kifunense sp. nov. FR-900494 exhibits a competitive action against immunosuppressive factor produced in the serum of tumor bearing mice and has the capacity to restore the depression of lymphocytes.

Production and biological activity of rebeccamycin, a novel antitumor agent.

An actinomycete, strain C-38,383, was selected in a screening program for the isolation of novel antitumor agents. A yellow crystalline product, named rebeccamycin, was isolated from the mycelium and was found to have activity against P388 leukemia, L1210 leukemia and B16 melanoma implanted in mice. Rebeccamycin inhibits the growth of human lung adenocarcinoma cells (A549) and produces single-strand breaks in the DNA of these cells. No DNA-protein cross-links were detected. A related antibiotic, staurosporine, is produced by Streptomyces staurosporeus and Streptomyces actuosus. Strain C-38,383 was found to resemble closely strains of Nocardia aerocolonigenes recently renamed Saccharothrix aerocolonigenes. A strain selection isolate without aerial mycelium, C-38,383-RK-1, failed to produce rebeccamycin while a strain with aerial mycelium, C-38,383-RK-2, was found to be a suitable strain for production. A description of the producing strain is presented and its taxonomic position is reviewed. A fermentor containing 37 liters of production medium gave a rebeccamycin yield of 663 mg/liter after 204 hours of incubation with strain C-38,383-RK-2.

Teicoplanin, antibiotics from Actinoplanes teichomyceticus nov. sp. VIII. Opening of the polypeptide chain of teicoplanin aglycone under hydrolytic conditions.

Hydrolysis of teicoplanin (a complex of five closely related factors plus one, more polar component) under selected conditions (acids in a biphasic hydroalcoholic medium) gives the single aglycone with good yields. When the reaction is carried out in homogeneous hydroalcoholic phase the removal of the sugars yields two new compounds. On the basis of fast atom bombardment mass spectra (FAB-MS), acid-base titration, IR, UV and 1H NMR analyses it has been demonstrated that these compounds are two diastereoisomers; they differ from the teicoplanin aglycone in having additional carboxyl and amino groups derived from the hydrolysis of an amide bond. Although the molecular shape of the new aglycones is greatly modified, they still maintain some antibacterial activity which might be correlated with residual binding ability towards the terminal D-alanyl-D-alanine residue of the cell-wall mucopeptides.

Analysis of cellular fatty acids by gas chromatography as a tool in the identification of medically important coryneform bacteria.

The fatty acid methyl esters of nineteen unidentified pathogenic coryneform bacteria were analysed by gas-liquid chromatography and the resulting profiles were compared with those of type or reference strains of possibly related species, namely Caseobacter polymorphus, Corynebacterium bovis, C. diphtheriae, C. xerosis and Rhodococcus equi. All of the strains had distinct fatty acid profiles but most of them conformed to a general pattern, with high levels of octadecanoic acids and only trace amounts of 10-methyl octadecanoic acid (tuberculostearic acid). These profiles were very similar to those from C. diphtheriae and C. xerosis but could be differentiated from C. bovis, Cas. polymorphus, R. equi and two unidentified pathogenic strains which had significantly higher levels of tuberculostearic acid.

Gas chromatography-mass spectrometry of mycolic acids as a tool in the identification of medically important coryneform bacteria.

The mycolic acid derivatives of 11 unidentified pathogenic coryneform bacteria were examined by TLC, GLC and GLC-mass spectrometry. The resulting mycolic acid profiles of the unidentified isolates were compared with those of type or reference strains of possibly related coryneform species, namely Corynebacterium bovis, C. diphtheriae, C. xerosis and Rhodococcus equi. It was apparent that most of the unidentified strains showed a distinctive mycolic acid profile, with predominant amounts of relatively high molecular weight mycolic acids (C32-C36) and a high degree of unsaturation, and could thus be distinguished from both C. bovis, which had exceptionally low molecular weight mycolic acids (C24-C30), and C. diphtheriae (C28-C34), which had large amounts of saturated mycolic acids. The mycolates of C. xerosis and R. equi (C28-C36) were generally similar to those of the unidentified coryneforms but their overall mycolic acid patterns were different from one another as well as the unidentified strains. The mycolic acid profiles exhibited by the pathogenic coryneforms examined here were very similar to one another but unlike that of any of the type or reference strains included in the study.

Vanoxonin, a new inhibitor of thymidylate synthetase.

Vanoxonin, a new inhibitor of thymidylate synthetase, was found in cultured broths of the strain MG245-CF2 classified as Saccharopolyspora hirsuta. Vanoxonin, C18H25N3O9, was obtained as colorless powder. Vanoxonin forms a vanadium complex which exhibits a strong inhibition against thymidylate synthetase. The concentration for 50% inhibition of the enzyme (IC50) was 0.7 micrograms/ml.

Antitumor activity of polysaccharide TC-13 extracted from rare actinomycetes.

The antitumor activities of mycelia and a hot-water extract of mycelia of rare actinomycetes were examined by three different antitumor assays in ddY mice with Ehrlich solid tumor. A new antitumor polysaccharide, TC-13, was prepared from the hot-water extract of Microellobosporia grisea by precipitation with cetylpyridinium chlorideborate complex and gel filtration. TC-13 was mainly composed of glucose and mannose with peptideglycan. Its molecular weight was determined to be 2-30 X 10(4) by gel filtration. Comparative studies suggested that the antitumor activity of TC-13 was equal to, or stronger than those of other antitumor agents (e.g., lentinan, PS-K, OK432 and yeast mannan). Screening methods for antitumor activity of actinomycetes were also discussed.

A new test system for screening macromolecular antitumor antibiotics and its application to culture fluids of actinomycetes.

In searching for macromolecular antitumor antibiotics, a new screening method was developed that consisted of 1) a macromolecular antibiotic detecting system employing macro-molecule permeable mutants of Escherichia coli, 2) a system to detect DNA-affecting antibiotics using DNA repair mutants, and 3) a mutagenicity detecting system, employing a valine resistance test. This new test system was applied to about 2,900 kinds of culture fluids of Actinomycetes and consequently 15 samples were found which contained macromolecular antibiotics with DNA affecting properties.

Screening and some properties of new macromolecular peptide antibiotics.

In searching for macromolecular antitumor antibiotics of microbial origin, 2,875 kinds of Actinomycetes culture fluids were applied to a newly developed test system which consisted of antimicrobial assay using a macromolecule permeable mutant, DNA damage assay and mutagenicity test. As a result, 78 macromolecular antibiotics were found. Among them, 15 antibiotics precipitable with ammonium sulfate were macromolecular peptide antibiotics (protein antibiotics), of which molecular weight ranged from 10,000 to 14,000. Macromolecular peptide antibiotics AN-1, -5 and -15, termed type I antibiotics, showed stronger growth inhibitory effect on the uvrA and recA mutants, as compared to the effect on their parent, MP2. They also had mutagenic activity. AN-7, -9, -16, -18, -20, -22, -23, -25, and -26, termed type II, exhibited an increased inhibitory activity to a recA mutant but did not to an uvrA mutant. They all showed mutagenicity. AN-3, -11 and -13, type III antibiotics, gave similar influence on the DNA repair mutants, and on their parent, MP2. They had no mutagenic activity. Except for AN-11 and -13 of type III antibiotics, all antibiotics were inhibitory to the cell growth of a cancer cell, L1210.

Microbial fermentation of rice straw: nutritive composition and in vitro digestibility of the fermentation products.

Rice straw was fermented with Cellulomonas sp. and Alcaligenes faecalis. Microbial cells and undigested residue, as well as chemically treated (NaOH or NH4OH) and untreated straws, were analyzed for nutrient composition and in vitro digestibility. In a typical fermentation, 75% of the rice straw substrate was digested, and 18.6% of the total substrate weight that disappeared was recovered as microbial protein. The microbial cell fraction was 37% protein and 5% crude fiber; the residue was 12% protein and 45% crude fiber. The microbial protein amino acid profile was similar to alfalfa, except for less cysteins. The microbial cells had more thiamine and less niacin than Torula yeast. In vitro digestibility of the microbial protein was 41.2 to 55%, that of cellulose was 52%.