Stoffwechselprodukte von Mikroorganismen 198. Mitteilung Die Eurekansäure,ein Abbauprodukt von Flambamycin und Avilamycin: Konfigurationsbestimmung durch Röntgenstrukturanalyse und Abbau

Eurekanic Acid, a Degradation Product of Flambamycin and Avilamycin: Determination of the Configuration by X-Ray Structural Analysis and Degradation The relative configuration of methyl O-acetyleurekanate (6) , obtained by mild methanolysis of avilamycin A (2) and subsequent acetylation, was determined by an X-ray structural investigation. Methyl dihydroeurekanate (7) , similarly obtained from avilamycin C (3) and from reduced avilamycin A methyl ether, was degraded to L-threonolactone (14) which allowed to determine the chirality of eurekanic acid (4).     

Stoffwechselprodukte von Mikroorganismen 227. Mitteilung. Isolierung und Strukturaufklärung von Rutamycin B

Isolation and Structure of Rutamycin B Botrycidin was found to be identical with rutamycin. From the cultures of the actinomycete producing botrycidin and the venturicidines. A and B, a fourth antifungal antibiotic, rutamycin B, was isolated. Through a series of degradation products its structure could be correlated to that of rutamycin, which had been determined before by an X-ray structural analysis. Rutamycin B has been identified as 12-deocy-rutamycin.     

Stoffwechselprodukte von Mikroorganismen. 174. Mitteilung Eine neue Synthese des Ferrichroms; enantio-Ferrichrom

Metabolites of Microorganisms. A New Synthesis of Ferrichrome; enantio-Ferrichrome The enantiomer of the natural sideramine ferrichrome was synthesized starting from D-ornithine. The cyclohexapeptide (D-Orn)₃-Gly₃ was obtained by conventional methods of polypeptide chemistry. For the oxidation of the δ-amino groups of the D-ornithine residues to hydroxylamino groups the oxaziridine pathway was successful. The final steps - introduction of the acetyl groups and formation of the iron trihydroxamate complex - followed known procedures. The spectroscopic and chromatographic properties of the crystalline product corresponded to those of natural ferrichrome, the optical rotations and CD. curves being opposite. The biological activity of enantio-ferrichrome was similar to that of the natural sideramine.     

Stoffwechselprodukte von Mikroorganismen. 250. Mitteilung. Maduraferrin,ein neuartiger Siderophor aus Actinomadura madurae

Maduraferrin, a Novel Siderophore from Actinomadura madurae From a strain of Actinomadura madurae, a new siderophore was isolated. Maduraferrin is the Fe complex of an oligopeptide composed of salicylic acid, β-alanine, glycine, L -serine, N^δ-hydroxy-N^α-methyl-L -ornithine, and L -hexahydropyridazine-3-carboxylic acid. The complexing centers are a salicylamide moiety, a hydroxamic-acid group and an acid hydrazide group.     

Stoffwechselprodukte von Mikroorganismen. 253. Mitteilung. Hormaomycin,ein neues Peptid-lacton mit morphogener Aktivität auf Streptomyceten

Hormaomycin, a Novel Peptide Lactone with Morphogenetic Activity on Streptomyces A culture identified as Streptomyces griseoflavus (strain W-384) has been found to produce a novel peptide-lactone antibiotic designated hormaomycin ( 6 ). The empirical molecular formula of the compound is established to be C₅₅H₆₉ClN₁₀O₁₄. The constituent amino acids of the antibiotic are suggested to be allothreonine ( 1 ; 1), isoleucine ( 2 ; 1), 3-methyl-phenylalanine ( 3 ; 2), and, for the first time identified from a natural source, 4-[(Z)-prop-1-enyl]-proline ( 4 ; 1) and 3-(2-nitrocyclopropyl)-alanine ( 5 ; 2). The amino acids were delivered by acidic hydrolysis and assigned by high-resolution- GC/MS analysis (after transformation to derivatives) in combination with extended 2D-NMR experiments of the antibiotic itself. From the latter, it became plausible that the N-terminus of the peptide chain is acylated by a Cl-containing derivative of 1H-pyrrol-2-carboxylic acid. Hormaomycin is active against some Gram-positive bacteria. In addition, the antibiotic exhibits potent aerial mycelium-inducing activity and effects the production of antibiotics.     

Stoffwechselprodukte von Mikroorganismen 217. Mitteilung Röntgenstrukturanalyse von O-Acetyldihydrostreptazolin

The X-ray crystal structure analysis of the O-acetyl dihydro derivative of the antibiotic streptazolin (orthorhombic, a = 8.628, b = 9.814, c = 14.932 Å, space group P2₁2₁2₁) established the constitution of the latter as 1.     

Stoffwechselprodukte von Mikroorganismen. 177. Mitteilung. Avilamycin C

From cultures of the Avilamycin (Avilamycin A) producing organism, Streptomyces viridochromogenes, strain ETH 23575, a second antibiotic, Avilamycin C, C₆₁H₉₀Cl₂O₃₂ could be isolated in crystalline form. Both Avilamycins belong to the group of the Orthosomycins. By IR., ¹H- and ¹³C-NMR. spectroscopy and by transformation to a common derivative it could be proven that Avilamycin A is a methyl ketone, Avilamycin C the corresponding methyl carbinol.     

Stoffwechselprodukte von Mikroorganismen. Granaticin B

From a strain of Streptomyces violaceoruber, ETH 11382, a new antibiotic, granaticin B. has been isolated. Granaticin B is an L -rhodinoside of the previously described antibiotic granaticin.     

Stoffwechselprodukte von Mikroorganismen. 210. Mitteilung. Über die Avilurekanosen A and C and weitere Abbauprodukte Avilamycine A and C

The Avileurekanoses A and C and Further Degradation Products of the Avilamycins A and C Alkaline hydrolysis of the orthosomycin antibiotics, avilamycins A ad C products similar t those earlier described for flambamycin. Among these avileurekanose c ( 15 ) became of particular importance because its acetate prisms suitable for an X-ray structural determination. For the avilamycins A and C structural formulae 2 and 3 , respectively, can now be drawn, in which only the configuration at C (16), one out of 32 asymmetric C-atoms, is not yet determined.     

Stoffwechselprodukte von Mikroorganismen. 233. Mitteilung. Danoxamin,der eisenbindende Teil des Sideromycin-Antibioticums Danomycin

Danoxamine, the Iron-Binding Moiety of the Sideromycin Antibiotic Danomycin The antibiotic danomycin was separated into its components, danomycin A and B ( 1 and 2 , resp.), by various methods. Danomycin A is a carbamate of danomycin B and can be transformed to the latter by boiling with H₂O. Both danomycins can be hydrolyzed by alkali to the Fe-containing moiety, danoxamine ( 3 ). The structure of the latter was determined by spectroscopy and chemical degradation as the Fe(III) complex of 5,16,27,32-tetrahydroxy-4,12,15,23,26-pentaoxo-5,11,16,22,27-pentaaza-dotriacontanoic acid. It belongs thus to the ferrioxamine family of siderophores. In the danomycins, this moiety is linked by an ester bond to a disaccharide moiety of unknown structure. One of the sugars is believed to be an aminohexane methyl ether. Chromatographically homogenous danomycins A and B are still mixtures of isomers, a neutral sugar being glucose or mannose.     

Stoffwechselprodukte von Mikroorganismen. 85. Mitteilung [1]. Zur Konstitution des Coprogens

The structure of coprogen, a fungal sideramine, has been determined by spectroscopic investigations and chemical degradation.     

Stoffwechselprodukte von Mikroorganismen 215. Mitteilung Röntgenstrukturanalyse von Di-O-acetyl-aspochalasin C

The X-ray crystal structure analysis of the 17,18-di-O-acetyl derivative of the antibiotic aspochalasin C (monoclinic, a = 26.377, b = 10.840, c = 11.937 Å, β = 102.08°, space group C 2) confirms the constitution elucidated by spectroscopic methods and chemical degradation, and establishes the relative configuration.     

Stoffwechselprodukte von Mikroorganismen. 216. Mitteilung. Isolierung,Strukturaufklärung und Synthese von Ferrioxamin H

Metabolites of Microorganisms. 216. Isolation, Structure and Synthesis of Ferrioxamine H The structure of ferrioxamine H , a minor component of the sideramine complex of actinomycetes, was determined by spectroscopic investigations, degradation and synthesis. Ferrioxamine H is the Fe (III)-complex of 11,22-dihydroxy-4, 12, 15, 23-tetraoxo-5,11,16,22-tetraazatetracosanoic acid ( 2 ).     

Über ein neues Verfahren zur Herstellung von. Acetylenverbindungen. Vorläufige Mitteilung

A new method for the preparation of acetylenes by reating α-halogeno- or α-sulfonyloxyketones with p-toluenesulfonylhydrazine is reported.     

Stoffwechselprodukte von Mikroorganismen. 75. Mitteilung [1]. Synthese des Ferrichroms; 2. Teil

Ferrichrome, a biologically active sideramine isolated from cultures of several strains of fungi, was synthesized starting from δ-nitro-L -norvaline and glycine. The intermediate trinitro-cyclohexapeptide 17 could be obtained in high yield by SCHWYZER 's method from the corresponding open-chain hexapeptide 16 .     

Stoffwechselprodukte von Mikroorganismen. 202. Mitteilung. Strukturaufklärung von Elaiophylin: Spektroskopische Untersuchungen und Abbau

Structure Elucidation of Elaiophylin: Spectroscopy and Chemical Degradation The structure of the antibiotic elaiophylin (azalomycin B) was elucidated by extended spectroscopic investigations and chemical degradation. Elaiophylin ( 26 ) is a macrodiolide with a 16membered dilactone ring. The synthesis of 7-acetoxy-6-ethyl-3-octanone ( 14 ), the acetyl derivative of an important degradation product, is described.