pyrimidinones and essramycin

Topics: Alkaloids; Antiviral Agents; Fungi; Fungicides, Industrial; Molecular Structure; Plant Diseases; Pyrimidinones; Structure-Activity Relationship; Tobacco Mosaic Virus; Triazoles; Virus Assembly

Four possible isomers of essramycin, a natural product from a marine Streptomyces species isolated from the Egyptian Mediterranean coast, were synthesized. The structures for the isomers were assigned unequivocally by (1)H NMR, (13)C NMR, high-resolution mass spectrometry, and X-ray crystal structure determinations. Notwithstanding the earlier report of broad-spectrum antibacterial activity for the natural product, none of the four isomers exhibited any such activity.

Topics: Anti-Bacterial Agents; Biological Products; Egypt; Marine Biology; Mediterranean Sea; Microbial Sensitivity Tests; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Pyrimidinones; Stereoisomerism; Streptomyces; Triazoles

A short synthesis of the 1,2,4-triazolo[1,5-a]pyrimidine antibiotic essramycin is described involving condensation of aminoguanidine with ethyl benzoylacetate to give an amino-1,2,4-triazole, followed by condensation with ethyl acetoacetate to form the pyrimidone ring.

Topics: Anti-Bacterial Agents; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Pyrimidinones; Streptomyces; Triazoles

The triazolopyrimidine natural product essramycin (1) was synthesized without the use of protecting groups via a two-step reaction scheme involving a 3-amino-1,2,4-triazole intermediate, and its structure was unequivocally determined. However, in contrast to the natural product, the synthetic essramycin (1) did not display any antibacterial activity.

Topics: Anti-Bacterial Agents; Microbial Sensitivity Tests; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Pyrimidinones; Streptomyces; Triazoles

In the course of our screening program for new bio-active compounds, a novel triazolopyrimidine antibiotic, essramycin (1), was obtained from the culture broth of the marine Streptomyces sp., isolate Merv8102. Structure 1 was established by intensive NMR studies and by mass spectra. The compound is antibacterially active with MIC of 2 to 8 microg/ml against Gram-positive and Gram-negative bacteria, while it showed no antifungal activity. The fermentation and isolation, as well as the structure elucidation and biological activity of 1 are described.

Topics: Anti-Bacterial Agents; Chemical Phenomena; Chemistry, Physical; Chromatography, Thin Layer; Fermentation; Gram-Negative Bacteria; Gram-Positive Bacteria; Indicators and Reagents; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microbial Sensitivity Tests; Molecular Conformation; Molecular Weight; Pyrimidines; Pyrimidinones; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Streptomyces; Triazoles