Froma strain of Streptomycesantibioticus seven yellow phenazines were isolated. The antibacterially most active antibiotic was identified as (-)-saphenamycin, a second one with compoundDC-86-Y(saphenic acid). Three compoundswere new: Saphenic acid methyl ether, 6-acetylphenazine-l-carboxylic acid and an inseparable mixture of fatty acid esters of saphenic acid. Twosimple phenazines were phenazine-1-carboxylic acid (tubermycin B) and unsubstituted phenazine, which was isolated for the first time from a microorganism.The most striking property of the actinomycete strain Tii 2706 was the dark green color of its extracts. The chemistry of the green pigments, the esmeraldines, will be described in a forthcoming paper. In addition to the esmeraldines a series of yellow pigments were present in the cultures. Since the chemical and spectroscopic properties of these compoundsare the basis of the structural elucidation of the esmeraldines, we describe them in this paper.The strain Tii 2706 could be identified by the classification of Hutter2) and Nonomura3) as Strep tomyces an tibio ticus.Most of the yellow pigments discernible by TLC in the crude extracts could be isolated in pure state by repeated chromatographic procedures under various conditions (see Experimental part).The following compounds were isolated and characterized :Saphenamycin (1) The only compoundpossessing high antibacterial activity was identical in its analytical and spectroscopic properties with saphenamycin (1), an antibiotic described by Umezawa'sgroup. Its structure follows from an X-ray study4). AnX-ray structural elucidation carried out independently in our laboratory50 gave identical results. We have further characterized saphenamycin by the preparation of the methyl ester (2) and the methyl ether methyl ester (3) which were formed from 1 by reaction with diazomethane. The dimethylated product (3) showed the same chromatographic and spectroscopic properties as a racemic synthetic sample6).From Umezawa'spaper one could have the impression that natural saphenamycin is a racemic compound ([a]D 0°in chloroform). Indeed our compound also did not show optical activity when measured in chloroform. However, in DMSO it is optically active, M2D4-3°. The esters 2 and 3Preceding communication see ref 1.
From a strain of Aspergillus nidulans var. echinulatus, A 32204, echinocandin, a novel polypeptide antibiotic complex with high and specific anti‐yeast activity was isolated. The main component, echinocandin B, was separated by counter‐current distribution. A tentative molecular formula C52H81N7O18 is discussed. The antibiotic is characterized by its IR. and NMR. spectra and by its characteristic hydrolytic degradation products: linoilic acid, L‐4‐hydroxyproline, L‐4‐oxoproline, (2S, 3S, 4S)‐4‐methyl‐3‐hydroxy‐proline, L‐threonine (2 mols), and 1‐(p‐hydroxyphenyl)‐3‐amino‐propan‐2‐one.
Streptazolin, a lipophilic neutral compound giving a yellow colour reaction with Ehrlich reagent, was isolated from cultures of Streptomyces viridochromogenes, strain Tü‐1678. On the basis of a “chemical screening”. Its structure, 1, was determined by spectroscopic investigations and chemical degradations. Dihydrostreptazolin 3 exhibits limited antimicrobial activities. Pharmacological investigations are in progress.
Von den in der vorhergehenden Mitteilung beschriebenen 7 Ferrioxaminen aus den Kulturen von Streptomyces pilosus ETTLINGER et al. besitzt das Ferrioxamin B nicht nur die starkste Sideramin-Wirkung2), sondern stellt auch gewichtsmassig den Hauptanteil des Gemisches dar. Es wurde deshalb als erster Vertreter dieser Verbindungsreihe eingehender chemisch untersucht.Das Ferrioxamin-B-hydrochlorid, das als Ausgangsmaterial fur unsere Untersuchungen diente, stellt ein braunrotes amorphes Pulver dar, welches die fur analoge Eisen(II1)-Komplexe typische breite Bande bei 430440 mp (EFkm = 39) zeigte; im UV. liegt dagegen bis auf eine Endabsorption keine typische Absorptionsbande vor. Von den starken Banden im 1R.-Absorptionsspektrum (in Kaliumbromid) sind besonders diejenigen bei 3430, 1640 und 1580 cm-l, die auf NH-CO-Gruppen hin-weisen3), erwahnenswert. Da das Ferrioxamin-B-Ion bei der Elektrophorese in 0 , 3 3~ Essigsaure als Kation wandertl), handelt es sich offensichtlich um ein Ammonium-Ion, worauf auch der pK&Wert 9,74 hinweist, welcher im Bereich der Werte fur aliphatische Ammonium-Ionen 4, liegt. Die analytischen Ergebnissel) stimmen gut mit der Formel C,5H4,0,N,FeC1 uberein, die auf Grund der Abbauergebnisse abgeleitet wurde.Besonders wichtig fur die Konstitutionsaufklarung der Ferrioxamine sind die Ergebnisse der sauren Hydrolyse nach der Entfernung von Eisen(II1)-Ionen. Vorversuche zeigten, dass eine direkte Hydrolyse des Ferrioxamins B, also in Gegenwart von Eisen(II1)-Ionen, zu einem Gemisch von Verbindungen fuhrt, welche durch Nebenreaktionen von primaren Hydrolyseprodukten mit diesen Ionen entstehen. Die letzteren wurden deshalb nach Versetzen des Ferrioxamins B mit 6 N Salzsaure durch erschopfende Extraktion mit Ather als Eisen(II1)-chlorid vor der Hydrolyse entfernt. Als Endprodukt der Hydrolyse wurden dann nur Essigsaure, Bernsteinsaure und I-Amino-5-hydroxylamino-pentan papierchromatographisch nachgewiesen und praparativ isoliert.
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