Isokibdelones: novel heterocyclic polyketides from a Kibdelosporangium sp

[Structure: see text] The isokibdelones are an unprecedented family of polyketides produced by an Australian isolate of a rare actinomycete, Kibdelosporangium sp. The structures of the isokibdelones were assigned by spectroscopic analysis and chemical interconversion. A proposed biosynthesis requires a novel molecular twist that generates an unprecedented heterocyclic system and differentiates the isokibdelones from their kibdelone co-metabolites. SAR analysis on the isokibdelones further defines the anticancer pharmacophore of these novel polyketides.     

Mononuclear boron(III) complexes of neo bidentate thioimines derived from hydrazinecarbodithioic acid

Boron chemistry has been intensively studied in the recent past. Although the study of the interactions between transition‐metal ions and the phenyl methylene ester derivatives of hydrazine carbodithioic acids has been carried out on a long period, particularly via the formation of adducts, their interaction of Main Group metal ions and the formation of their coordination complexes are subjects of current interest. We have synthesized and isolated a variety of complexes of phenyl dihydroxyborane with substituted dithiocarbazates. The benzene‐soluble, high‐molecular‐weight complexes have been characterized using a wide range of analytical and spectroscopic techniques. The pathogenicity of microbial infections associated with the complexes have been subjected to a variety of biointeraction studies and the results are discussed. Copyright © 1999 John Wiley & Sons, Ltd.     

Photoinitiated Energy Transfer in Porous-Cage-Stabilised Silver Nanoparticles

We report a new composite material consisting of silver nanoparticles decorated with three-dimensional molecular organic cages based on light-absorbing porphyrins. The porphyrin cages serve to both stabilize the particles and allow diffusion and trapping of small molecules close to the metallic surface. Combining these two photoactive components results in a Fano-resonant interaction between the porphyrin Soret band and the nanoparticle-localised surface-plasmon resonance. Time-resolved spectroscopy revealed the silver nanoparticles transfer up to 37 % of their excited-state energy to the stabilising layer of porphyrin cages. These unusual photophysics cause a 2-fold current increase in photoelectrochemical water-splitting measurements. The composite structure provides a compelling proof of concept for advanced photosensitiser systems with intrinsic porosity for photocatalytic and sensing applications.