Microalga Chlorella sorokiniana: a new sulfoxidation biocatalyst

Whole cells of the microalga Chlorella sorokiniana were evaluated in the oxidation of prochiral thioethers as regards conversion, enantiomeric excess and enantioselectivity.     

Acetogenins in Annona muricata L. (annonaceae) leaves are potent molluscicides

An ethanolic extract of the leaves of Annona muricata was shown to be toxic to adult forms of the snail Biomphalaria glabrata (LC50 9.32 microg mL(-1)) and to larvae of the brine shrimp Artemia salina (LC50 0.49 microg mL(-1)). Activity-guided fractionation of the extract gave rise to a sample with high molluscicidal activity that contained the acetogenins, annonacin (90%), isoannonacin (6%) and goniothalamicin (4%).     

Versatile precursors of functional RAFT agents. Application to the synthesis of bio-related end-functionalized polymers

Biomolecule-polymer conjugates are widely used in bio-related fields, but their synthesis is often tricky, especially the introduction of a single biomolecule at one chain end. This paper describes a new straightforward approach to prepare such conjugates via RAFT polymerization. By designing appropriate bio-related RAFT agents, polymer chains of controlled chain length (Mn = 10 000-40 000 and PDI < 1.1) carrying a single biomolecule as an alpha-end group (a sugar or a biotin) linked by a stable amide bond are obtained. Considering the versatility of the RAFT process, this strategy appears to be very attractive for the design of a variety of conjugates.     

An easy route towards regioselectively difunctionalized cyclens and new cryptands

Reductive amination of various aldehydes with cyclen represents a very convenient method for the synthesis of a wide range of 1,7-difunctionalized cyclens, as well as new cryptands.     

Highly luminescent gels and mesogens based on elaborated borondipyrromethenes

Supramolecular gels and liquid-crystalline materials containing borondipyrromethene (F-Bodipy) are a new class of highly luminescent materials built by attachment of long-chain alkoxydiacylamido scaffoldings to boradiazaindacene templates. Robust gels were formed in nonane, and luminescence spectroscopy was used to probe the aggregation processes of the flat indacene cores. Coincidently, columnar mesophase was obtained from the pure material over a wide temperature range, allowing textural observations by fluorescence microscopy.     

Oxidation of aromatic lithium thiolates into sulfinate salts: an attractive entry to aryl sulfones labeled with carbon-11

[reaction: see text] Aromatic 11C-sulfones were synthesized by S alkylation of lithium arenesulfinates, which are readily available from the corresponding thiols by an oxaziridine-mediated oxidation reaction with [11C]alkyl iodides in THF/H2O (4:1) at 150 degrees C. The radiosyntheses, including purification by HPLC, were completed in an average of 35 min from the end of the bombardment with 55-76% overall radiochemical yields (decay corrected). The described procedure extends the range of accessible labeling methods.     

In situ Fe XAFS of reversible lithium insertion in a flexible metal organic framework material

X-ray absorption fine structure (XAFS) analysis of the Fe K-edge during lithium insertion and extraction into the metal organic framework material MIL-53 (Fe^III(OH, F)bdc; bdc = benzene-1,4-dicarboxylate) reveals changes in local atomic environment about iron during the process. The average oxidation state of iron is reduced upon lithium insertion, as evidenced by the edge shift of the XANES spectra, and this is accompanied by a lengthening of Fe–O bonds, seen in the EXAFS. In contrast, the EXAFS analysis shows that the closest Fe–Fe distance remains approximately constant during the insertion and extraction of lithium, consistent with a distortion of the structure due to its flexible nature. The process is reversible upon lithium extraction, proving the redox-active flexibility of the framework.     

A new synthesis of alkane and polyfluoroalkanesulfonyl chlorides

This study describes a new and advantageous procedure for the synthesis of alkanesulfonyl chlorides ( 2 ) by the reaction of alkyl thiocyanates ( 1 ) with sulfuryl chloride in a mixture of acetic acid and water. The alkanesulfonyl chlorides were obtained in good yields. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:355–361, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20559     

Solid-State and Solution Self-assembly Properties of Mono- and Bis-acetylide RuII Complexes Bearing Hydrogen-Bonding Amide Functions

In this work, we report our latest results regarding the self-assembly properties of two Ru-acetylides complexes and their corresponding free organic ligands, in solution and in the solid state. The four compounds show mesogenic properties, which we have rationalized thanks to extensive DSC, SAXS, POM, FTIR and molecular dynamic investigations. We clearly establish that hydrogen bonds stabilize the supramolecular structures, and that introducing the metal center and its coordination sphere induces large change in the liquid crystal properties. In addition, for the monoacetylide compound Ru₂ , solution-state studies helped us rationalize its supramolecular abilities. In particular, we demonstrate that Ru₂ follows an isodesmic growth supramolecular polymerization in aromatic solvent.