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Ein Chelatbildner aus der sauerstofffreien Welt: Verschiedenste Experimente zeigen, dass Closthioamid, das erste Antibiotikum aus einem streng anaeroben Bakterium (Clostridium), ein selektiver Kupfer(I) ‐ Chelatbildner ist. Die Geometrie des Polythioamid ‐ Komplexes, in dem zwei Kupferionen in einer trigonal ‐ planaren Koordination die Windung einer Helix ‐ artigen Struktur stabilisieren, ist für Naturstoffe beispiellos. [ABSTRACT FROM AUTHOR]

Abstract: A novel pentacyclic indolosesquiterpene, named xiamycin (1), and its methyl ester (2) have been obtained from Streptomyces sp. GT2002/1503, an endophyte from the mangrove plant Bruguiera gymnorrhiza. The structures were established by 1D and 2D NMR, MS, and X-ray crystallography, and the absolute configuration of 1 was elucidated by the modified Mosher method. Compound 1 exhibits selective anti-HIV activity; it specifically blocks R5 but has no effects on X4 tropic HIV-1 infection. In a panel of cytotoxicity assays, compound 2 showed to be more potent (geometric mean IC50 =10.13μM) compared to compound 1 (geometric mean IC50 >30μM), with antitumor potency being generally less pronounced. Xiamycin represents one of the first examples of indolosesquiterpenes isolated from prokaryotes. [Copyright &y& Elsevier]

A pyridyl triazole (pyta) modified sucrose ligand was prepared in a seven step synthesis using d -glucose as the protection group for d -fructose and starting from commercially available sucrose. After complexation with Ru(bpy) 2 Cl 2 precursor, the sucrose-conjugated Ru complex of the general formula [Ru(bpy) 2 (L)]Cl 2 was formed. Acidic cleavage of the d -glucose unit led to the first d -fructose conjugated metal complex via d -fructose C6 in literature. Additionally, pyta-modified d -fructose via C1 and the corresponding Ru complex were synthesized. All compounds were analyzed by R f values, specific rotation, NMR, IR, UV/Vis and fluorescence spectroscopy, mass spectrometry and elemental analysis. [ABSTRACT FROM AUTHOR]

Ni-catalyzed cross-coupling reactions of arylcalcium iodides with aryl chlorides provide biphenyls in moderate yields. [ABSTRACT FROM AUTHOR]

A series of hemilabile 2-(imidazol-2-yl)pyridine and 2-(oxazol-2-yl)pyridine palladium ligands are synthesized, characterized, and their catalytic properties in high-temperature Suzuki-Miyaura cross-coupling reactions are investigated. [ABSTRACT FROM AUTHOR]

Title compounds prepared by reaction of 1,3-dicarbonyl compounds (I) with aldehydes are obtained as single crystals and their X-ray structures are given and discussed. [ABSTRACT FROM AUTHOR]

the UV/vis absorption and fluorescence properties in tetrahydrofuran are also investigated [ABSTRACT FROM AUTHOR]

The compounds′ fluorescence properties in solid state as well as in polar solvents (EtOH, DMSO) in absence and presence of NaOH and HCl are examined. [ABSTRACT FROM AUTHOR]

Review: 181 refs. [ABSTRACT FROM AUTHOR]

The reaction of diphenylphosphane oxide (I) with isocyanates (II) and isothiocyanates (IV) in the presence of a calcium catalyst leads to desired formamides (III) and thioformamides (V), respectively. [ABSTRACT FROM AUTHOR]

Oxidative cyclization of di(arylamino)quinoxalines (I) results in the unexpected formation of bridged bis-benzimidazoles (II), which show a strong fluorescence in the blue region. [ABSTRACT FROM AUTHOR]

Caryolanes are known as typical plant-derived sesquiterpenes. Here we describe the isolation and full structure elucidation of three caryolanes, bacaryolane A-C (1-3), that are produced by a bacterial endophyte (Streptomyces sp. JMRC:ST027706) of the mangrove plant Bruguiera gymnorrhiza. By 2D NMR, analysis of the first X-ray crystallographic data of a caryolane (bacaryolane C), CD spectroscopy, and comparison with data for plant-derived caryolanes, we rigorously established the absolute configuration of the bacaryolanes and related compounds from bacteria. Bacterial caryolanes appear as the mirror images of typical plant caryolanes. Apparently plant and bacteria harbor stereodivergent biosynthetic pathways, which may be used as metabolic signatures. The discovery of plant-like volatile terpenes in endophytes not only is an important addition to the bacterial terpenome but may also point to complex molecular interactions in the plant-microbe association.