Directed biosynthesis of novel derivatives of echinomycin by Streptomyces echinatus. I. Effect of exogenous analogues of quinoxaline-2-carboxylic acid on the fermentation

1984 ◽  
Vol 30 (4) ◽  
pp. 439-450 ◽  
Author(s):  
D. Gauvreau ◽  
M. J. Waring
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Time Course ◽  
Biologically Active ◽  
Aromatic Acids ◽  
Gram Positive Bacteria ◽  
Directed Biosynthesis ◽  
Derivatives Of ◽  
Carbonyl Chromophores

Streptomyces echinatus A8331 cultured on a maltose minimal salts medium normally produces a single antibiotic, echinomycin (quinomycin A), containing two quinoxaline-2-carbonyl chromophores. Echinomycin is powerfully active against experimental tumours and can be assayed by its activity against Gram-positive bacteria. Grown in the presence of aromatic carboxylic acids related to quinoxaline, S. echinatus responds in favourable circumstances by incorporating the added material into analogues of the natural antibiotic having replacement chromophores. Both mono- and bis-substituted derivatives are formed. With quinoline-2-carboxylic acid as precursor, large quantities of analogues are produced, and the time course of synthesis, extraction, purification, assay, and characterization of the derivatives are described. Twenty-two other aromatic acids have been tested as potential substrates for antibiotic analogue biosynthesis. Half of them did not significantly affect growth and echinomycin production. Five appeared to stimulate antibiotic synthesis, while the remainder proved inhibitory. New biologically active antibiotics were detected in cultures supplemented with 7-chloroquinoxaline-2-carboxylic acid; 1,2,4-benzo-as-triazine-3-carboxylic acid; thieno[3,2-b]pyridine-5-carboxylic acid; and 6-methylquinoline-2-carboxylic acid.

Characterization of Carboxylic Acids: Identification of Their Anilide Derivatives by X-ray Diffractometry

1976 ◽  
Vol 30 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Kenneth J. Garska
Keyword(s):  
Mass Spectrometry ◽  
Carboxylic Acid ◽  
Qualitative Analysis ◽  
Carboxylic Acids ◽  
Isomeric Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Derivatives Of

In order to extend the data available for the characterization of carboxylic acids, an x-ray diffraction technique has been used for the identification of their anilide derivatives. This technique often makes possible the identification of carboxylic acids that cannot be examined readily by other techniques such as gas chromotography and mass spectrometry. Reference x-ray diffraction patterns have been obtained for the anilide derivatives of 32 carboxylic acids containing up to 18 carbon atoms. Detailed descriptions are given for obtaining and qualitatively using the x-ray diffraction patterns of these anilides. The x-ray diffraction patterns of these anilides are unique; even closely related acids which differ only in isomeric form produce anilide derivatives which exhibit different and characteristic x-ray diffraction patterns. In the qualitative analysis of single or multicomponent carboxylic acid-containing mixtures, this x-ray diffraction technique is used either alone or with infrared spectrometric techniques.

Directed biosynthesis of novel derivatives of echinomycin. II. Purification and structure elucidation

1984 ◽  
Vol 30 (6) ◽  
pp. 730-738 ◽  
Author(s):  
D. Gauvreau ◽  
M. J. Waring
Keyword(s):  
High Performance ◽  
Reversed Phase ◽  
Aromatic Acids ◽  
Antibacterial Assay ◽  
New Antibiotics ◽  
Field Desorption Mass Spectrometry ◽  
Directed Biosynthesis ◽  
Phase Systems ◽  
Derivatives Of ◽  
Acid Precursor

New antibiotics produced by Streptomyces echinatus A8331 cultured in the presence of heterocyclic aromatic acids can be separated and purified by high-performance liquid chromatography using reversed phase columns. Natural quinoxaline antibiotics and certain quinoline derivatives can also be efficiently separated in normal phase systems. Details of purification procedures are described together with experiments to characterise the new antibiotics by field desorption mass spectrometry and proton magnetic resonance. Mono- and bis-substituted derivatives of echinomycin containing the following replacement chromophores have been isolated: 7-chloroquinoxaline-2-carbonyl, thieno[3,2-b]pyridine-5-carbonyl, and 6-methylquinoline-2-carbonyl. With a 6-methylquinoline-2-carboxylic acid precursor the analogues containing one or two replacement chromophores are each separable into two distinct components. One of the bis-substituted 6-methylquinoline products appears inactive in an antibacterial assay and behaves as a triostin analogue, presumably an immediate precursor of the corresponding echinomycin derivative.

Isocarbostyrils. II. The Conversion of 2-Methyl-4-acyl-5-nitroisocarbostyrils to 2-Substituted Indole-4-carboxylic Acids

1971 ◽  
Vol 49 (17) ◽  
pp. 2797-2802 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski
Keyword(s):  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Alkaline Hydrolysis ◽  
Mannich Reaction ◽  
Reductive Cyclization ◽  
Acid Catalyzed ◽  
Acid Anhydrides ◽  
Hydrolysis Of ◽  
Derivatives Of

The sulfuric acid catalyzed acylation of 2-methyl-5-nitroisocarbostyril with carboxylic acid anhydrides gave the corresponding 4-acylated derivatives 3, which underwent reductive cyclization to 2-substituted derivatives of 4-methyl-1,3,4,5-tetrahydropyrrolo[4.3.2.de]isoquinolin-5-one (4). Alkaline hydrolysis of the six-membered lactam in 4 was accompanied by a retro-Mannich reaction to produce 2-substituted indole-4-carboxylic acids in about 40 % overall yield from 3.

Synthesis and structural characterization of derivatives of 2- and 3-benzo[b]furan carboxylic acids with potential cytotoxic activity

Il Farmaco ◽  
2005 ◽  
Vol 60 (6-7) ◽  
pp. 519-527 ◽  
Author(s):  
Jerzy Kossakowski ◽  
Kinga Ostrowska ◽  
Elżbieta Hejchman ◽  
Irena Wolska
Keyword(s):  
Cytotoxic Activity ◽  
Carboxylic Acids ◽  
Structural Characterization ◽  
Derivatives Of

scholarly journals Synthesis and Evaluation of Antimicrobial and Cytotoxic Activity of Oxathiine-Fused Quinone-Thioglucoside Conjugates of Substituted 1,4-Naphthoquinones

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3577
Author(s):  
Yuri E. Sabutski ◽  
Ekaterina S. Menchinskaya ◽  
Ludmila S. Shevchenko ◽  
Ekaterina A. Chingizova ◽  
Artur R. Chingizov ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Cytotoxic Activity ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
Hydroxyl Group ◽  
Diffusion Method ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
High Cytotoxic Activity ◽  
Derivatives Of

A series of new tetracyclic oxathiine-fused quinone-thioglycoside conjugates based on biologically active 1,4-naphthoquinones and 1-mercapto derivatives of per-O-acetyl d-glucose, d-galactose, d-xylose, and l-arabinose have been synthesized, characterized, and evaluated for their cytotoxic and antimicrobial activities. Six tetracyclic conjugates bearing a hydroxyl group in naphthoquinone core showed high cytotoxic activity with EC50 values in the range of 0.3 to 0.9 μM for various types of cancer and normal cells and no hemolytic activity up to 25 μM. The antimicrobial activity of conjugates was screened against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus), Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), and fungus Candida albicans by the agar diffusion method. The most effective juglone conjugates with d-xylose or l-arabinose moiety and hydroxyl group at C-7 position of naphthoquinone core at concentration 10 µg/well showed antimicrobial activity comparable with antibiotics vancomicin and gentamicin against Gram-positive bacteria strains. In liquid media, juglone-arabinosidic tetracycles showed highest activity with MIC 6.25 µM. Thus, a positive effect of heterocyclization with mercaptosugars on cytotoxic and antimicrobial activity for group of 1,4-naphthoquinones was shown.

Photochemical reactions of azo compounds. X. Photochemical properties of azobenzene-2-carboxylic acids

1967 ◽  
Vol 20 (5) ◽  
pp. 929 ◽  
Author(s):  
CP Joshua ◽  
GE Lewis
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Intramolecular Hydrogen Bonding ◽  
Photochemical Reactions ◽  
Azo Compounds ◽  
Neutral Compounds ◽  
Methyl Derivatives ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

Two chloro and two methyl derivatives of azobenzene-2-carboxylic acid have been found to yield the corresponding derivatives of benzo[c]cinnoline-4- carboxylic acid in good yields when irradiated in 98% sulphuric acid. The question of intramolecular hydrogen bonding in relation to the properties of azobenzene-2-carboxylic acids is discussed. Infrared absorption spectra of the neutral compounds have provided confirmation of internal hydrogen bonding. Attempts to prepare the cis isomers of these azo compounds have been unsuccessful.

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