Structure of a novel Ca2+ and calmodulin-dependent cyclic nucleotide phosphodiesterase inhibitor K-259-2.

The structure of K-259-2, a potent inhibitor of Ca2+ and calmodulin-dependent cyclic nucleotide phosphodiesterase, was determined to be 3-(2Z-2-ethyl-2-butenyl)-1,6,8-trihydroxy-anthraquinone-2-carboxyl ic acid by chemical conversion and spectral studies.

Studies on a new nucleoside antibiotic, dapiramicin. II. Isolation, physico-chemical and biological characterization.

New nucleoside antibiotics, dapiramicins A and B produced by a Micromonospora sp. SF-1917, have been isolated by column chromatography on Diaion HP-20 and silica gel. Physico-chemical properties suggested that they are disaccharide nucleosides. Dapiramicin A underwent epimerization, under acidic condition, into epidapiramicin A. Although dapiramicin A generally exhibits no in vitro activity, it is very effective against the sheath blight of rice plants caused by Rhizoctonia solani in a green house test.

[Comparative study of the lipid composition of seven species of "Micromonospora"]. / Etude comparative de la composition en lipides de sept espèces de Micromonospora.

Analysis of the lipids of seven species of Micromonospora showed the constant presence of five phospholipids and three glycolipids. The phospholipids were identified as cardiolipids, phosphatidylethanolamine, phosphatidyl-inositol, mannosides of phosphatidyl-inositol, and possibly lysocardiolipids. The glycolipids were monoglucosyl-diglycerides, diglucosyl-diglycerides (with a small amount of galactosyl-glucosyl-diglycerides) and esters of fatty acids and trehalose. The simultaneous presence of glucosyl-diglycerides and trehalose esters might be specific of the genus Micromonospora. In the seven species studied, a large amount of the total fatty acids (obtained by direct saponification of the cells) consisted of iso and anteiso fatty acids. Three groups could be distinguished, having respectively iso-C15, iso-C16 and n-C17 fatty acids as the main members. A monounsaturated C17 acid has been identified as heptadec-9,10-enoic acid.

Studies on a new antibiotic M-92 produced by Micromonospora. II. Isolation and physicochemical properties of M-92 and its components.

A new antibiotic complex, M-92 was isolated from the whole fermentation broth of Micromonospora verruculosa MCRL 0404. The whole broth was mixed with talc and filtered. The filter cake thus obtained was extracted with acidic methanol to give a crude powder of M-92 complex, which was then separated into A (acidic) and N (neutral or weakly acidic) groups. The A group components are soluble in alkaline water (pH 8.5), while the N group components are not. These components were further separated into six major components designated VA-2, BA-4, BA-5, BN-1, BN-2 and BN-3 by silica gel column chromatography. Components with the letter "V" are reddish violet and those with "B" are blue. The IR and UV spectra of these components suggest that their chromophores may be the same or very closely related to one another. The molecular formula of BN-3 was determined to be C29H23NO9 by mass spectrometry. The results of various spectroscopies on BN-3 suggest that M-92 components consisted of chromophores in which juglone (5-hydroxynaphthoquinone) is conjugated with naphthazarin (5,8-dihydroxynaphthoquinone).

Studies on a new antibiotic M-92 produced by Micromonospora. III. Biological activities.

The six major components of M-92, a new antibiotic complex produced by Micromonospora verruculosa MCRL 0404 showed a similar type of antimicrobial spectrum. Among these components, VA-2 exhibited the most potent antimicrobial activity, particularly significantly against some Gram-positive bacteria and Neisseria. VA-2 and BN-1 also exhibited marked inhibitory effects against L-forms of Staphylococcus aureus 209P and Mycoplasma. The MICs of VA-2, BA-4 and BN-1 were remarkably affected by the pH of the test medium, the inoculum size and the amount of horse serum added in the medium. By intraperitoneal administration, these components showed good protective effects in mice infected intraperitoneally with Staphylococcus aureus Smith. However, the protective effect decreased remarkably by other administration routes. In addition, components such as VA-2 and BN-1 exhibited cytotoxicity against HeLa S-3 cells in vitro and excellent in vivo antitumor activity against Ehrlich carcinoma. VA-2 possessed a high order of acute toxicity to mice [LD50:1.9 mg/kg (i.p.); 1.8 mg/kg (i.v.)], but others were relatively less toxic.

Cell wall composition of Micromonospora olivoasterospora, Micromonospora sagamiensis, and related organisms.

Cell walls of 19 Micromonospora species were analyzed for their components. All the cell walls had xylose and arabinose, but the presence of glucose, galactose, mannose, or rhamnose depended on the strain. Amino acids present in the walls consisted of glycine, glutamic acid, diaminopimelic acid, and alanine, in a molar ratio of approximately 1:1:1:0.6--0.8. 3-Hydroxydiaminopimelic acid, together with meso-diaminopimelic acid, was found in many species and was isolated from Micromonospora olivoasterospora to compare the color constant in an amino acid analyzer with that of meso-diaminopimelic acid. The cell walls of Micromonospora sagamiensis and M. olivoasterospora contained only D-alanine and not L-alanine. All species tested except Micromonospora globosa contained glycolate in an almost equimolar ratio to diaminopimelic acid in their cell walls. Among 45 strains of 12 genera examined, Actinoplanes, Ampullariella, Amorphosporangium, and Dactylosporangium species had a significant amount of glycolate in the whole cells. Based on these results, the primary structure of the peptidoglycan of Micromonospora is discussed.

Isolation of N-(2,6-diamino-6-hydroxymethylpimelyl)-L-alanine from Micromonospora chalcea.

A novel dipeptide, N-(2,6-diamino-6-hydroxymethylpimelyl)-L-alanine, was isolated from the culture broth of a microorganism identified as Micromonospora chalcea. The dipeptide exhibits antimicrobial activity against Escherichia coli on a synthetic medium, and the activity is synergistically enhanced by several cell wall synthesis-inhibitors.

A new actinomycin complex produced by a Micromonospora species: fermentation, isolation, and characterization.

A species of Micromonospora, Micromonospora floridensis NRRL 8020, has been found to produce an actinomycin complex consisting of at least 25 active components. After solvent extraction of the complex, separation of the individual components was carried out by preparative thin-layer chromatography. Hydrolysis and subsequent electrophoretic and chromatographic identification of the amino acid content of each of the isolated components have shown differences from known actinomycins, and the probability exists that these contain a number of amino or imino acids not previously found in other members of this group of antibiotics.

In vitro activity of sisomicin, an aminoglycoside antibiotic, against clinical isolates.

Sisomicin, a new aminoglycoside antibiotic which is produced by Micromonospora myoensis, was studied against 565 clinical isolates of gram-negative bacilli and gram-positive cocci. With the exception of Serratia marcescens, over 90% of isolates of gram-negative bacilli were inhibited by 1.56 mug/ml or less of sisomicin. Sisomicin was slightly more active than gentamicin and tobramycin aganist isolates of Escherichia coli, Proteus mirabilis and Klebsiella spp. It was substantially more active than butirosin and kanamycin against all gram-negative bacilli. Isolates of gram-negative bacilli which were resistant to gentamicin and tobramycin were also resistant to sisomicin. Most of these isolates were sensitive to amikacin.

The gentamicin antibiotics. 6. Gentamicin C2b, an aminoglycoside antibiotic produced by Micromonospora purpurea mutant JI-33.

A mutant strain of Micromonospora purpurea, designated var. JI-33, produced an antibiotic complex consisting primarily of gentamicin C1a. A further product of this fermentation was identical to a very minor component isolated from the fermentation of the parent organism and named gentamicin C2b. Physical measurements indicated its structure to be 6'-N-methylgentamicin C1a and this was confirmed by synthesis from gentamicin C1a. The in vitro antibacterial activity of gentamicin C2b was very similar to that of the gentamicin C complex. Antibiotic XK-62-2, produced by Micromonospora sagamiensis, appears to be identical to gentamicin C1b.