Two new antibiotics, A-218 and K-41, were isolated from strains identified as Streptomyces hygroscopicus. The antibiotics are characterized as polycyclic polyether compounds and are active against gram-positive bacteria.

The compound (bpy) 2Mn (III)(mu-O) 2Mn (IV)(bpy) 2, a structural model relevant for the photosynthetic water oxidation complex, was coupled to single Cr (VI) charge-transfer chromophores in the channels of the nanoporous oxide AlMCM-41. Mn K-edge EXAFS spectroscopy confirmed that the di-mu-oxo dinuclear Mn core of the complex is unaffected when loaded into the nanoscale pores. Observation of th...

The title compound, C(51)H(78)N(4)O(12), is a derivative of rapamycin, a triene macrolide anti-biotic mol-ecule isolated from Streptomyces hygroscopicus. The macrocyclic ring structure has 15 chiral centres, with one of the substituent hy-droxy groups giving an intra-molecular hydrogen bond to a ketone O-atom acceptor. The mol-ecules also form inter-molecular hy-droxy-ketone O-H⋯O hydrogen-bond...

G. S. Collins and Y. Le Manach Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK, and Departments of Anesthesia and Clinical Epidemiology and Biostatistics, Michael DeGroote School of Medicine, Faculty of Health Sciences, Population Health Research Institute, McMaster University and the Perioperati...

Acta Crystallographica Section A: Foundations of Crystallography covers theoretical and fundamental aspects of the structure of matter. The journal is the prime forum for research in diffraction physics and the theory of crystallographic structure determination by diffraction methods using X-rays, neutrons and electrons. The structures include periodic and aperiodic crystals, and non-periodic d...