Characteristics of marine strain Streptomyces sp. with antimicrobial and cytotoxic activity

The Black Sea is a unique water basin consisting of a thin superficial oxygenic layer with moderate salinity, and a deep anoxic water mass. The microbiota of the Black Sea remains relatively understudied, which makes it interesting first of all from the most practical point of view of the search for producers of new biologically active compounds. A strain of actinobacteria Streptomyces sp. ONU 561 was isolated from the surface of mussel shells collected in the coastal zone of Odesa. It demonstrated a wide range of antagonistic activity, inhibiting the growth of a set of opportunistic pathogens, including representatives of Staphylococcus aureus, Escherichia coli, Proteus vulgaris, and Klebsiella pneumoniae. In addition, bacteria of this strain were able to inhibit the growth of all tested strains of mycelial fungi, including representatives of Aspergillus niger, A. flavus and Fusarium oxysporum species, and Candida albicans yeast. A significant cytotoxic effect was revealed in the cell cultures of human malignant cells – human rhabdomyosarcoma (RD) and human laryngeal adenocarcinoma (Hep-2). Analysis of the exometabolome of the strain did not explain these effects.The strain was comprehensively characterized, including physiological, biochemical, and morphological traits. The complete genome of the strain was sequenced using Illumina HiSeq 4000 (2x150) and ONT and annotated using NCBI PGAP. Its genome has a size of 8 359 197 bp. GC content – 71.59%. Using antiSMASH 7.0, 35 biosynthetic clusters were revealed. The indices of digital DNA-DNA hybridization and orthoANI for all of the type strains with Streptomyces sp. ONU 561 are much lower than threshold values for the species separation. The obtained results, including a comparative analysis of the genome, indicate the possible affiliation of the strain Streptomyces sp. ONU 561 to a new species and the potential ability of these actinobacteria to synthesize previously unknown antibiotic compounds

Crystal structure of poly[μ2-aqua-aqua(μ<inf>2</inf>-4-nitro-2,5,6-trioxo-1,2,5,6-tetrahydropyridin-3-olato)-hemi-μ<inf>4</inf>-oxalato-barium(II)]

In the title coordination polymer, [Ba(C5HN2O6)(C2O4)0.5(H2O)2]n, the tenfold coordination of the Ba centre consists of four O atoms from the two 4-nitro-2,5,6-trioxo-1,2,5,6-tetrahydropyridin-3-olate (L) anions, three O atoms of two oxalate anions and three water molecules. The Ba - O bond lengths fall in the range 2.698 (3)-2.978 (3) Å. The L ligand chelates two Ba atoms related by a screw axis, leading to formation of fused five- and six-membered chelate rings. Due to the bridging function of the ligands and water molecules, the complex monomers are connected into polymeric two-dimensional layers parallel to the bc plane. Intermolecular O - H⋯O hydrogen bonds link these layers into a three-dimensional supramolecular framework

Crystal structure of poly[μ2-aqua-aqua(μ<inf>2</inf>-4-nitro-2,5,6-trioxo-1,2,5,6-tetrahydropyridin-3-olato)-hemi-μ<inf>4</inf>-oxalato-barium(II)]

In the title coordination polymer, [Ba(C5HN2O6)(C2O4)0.5(H2O)2]n, the tenfold coordination of the Ba centre consists of four O atoms from the two 4-nitro-2,5,6-trioxo-1,2,5,6-tetrahydropyridin-3-olate (L) anions, three O atoms of two oxalate anions and three water molecules. The Ba - O bond lengths fall in the range 2.698 (3)-2.978 (3) Å. The L ligand chelates two Ba atoms related by a screw axis, leading to formation of fused five- and six-membered chelate rings. Due to the bridging function of the ligands and water molecules, the complex monomers are connected into polymeric two-dimensional layers parallel to the bc plane. Intermolecular O - H⋯O hydrogen bonds link these layers into a three-dimensional supramolecular framework

X-ray diffraction studies of 6-methyl-5-acetyl-4-α -furyl-2-keto-1,2,3,6-tetrahydropyrimidine and 6-methyl-5-acetyl-4-γ -bromophenyl-2-thio- 1,2,3,6-tetrahydropyrimidine

6-Methyl-5-acetyl-4-α-furyl-2-keto-1,2,3,6-tetrahydropyrimidine (I) and 6-methyl-5-acetyl-4-γ-bromophenyl-2-thio-1,2,3,6-tetrahydropyrimidine (II) are prepared by the modified Biginelli reaction, and their crystal and molecular structures are studied. It is shown that, in crystals I and II, the pyrimidine ring has an amide tautomeric form and adopts a sofa conformation. The IR absorption spectra are analyzed, and the stability of the tautomers of the pyrimidine fragments is evaluated using quantum-chemical calculations. © 2003 MAIK "Nauka/Interperiodica"