351003-10-6Relevant articles and documents
COMBRETASTATIN DERIVATIVE PREPARATION METHOD
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Page/Page column 5-6, (2012/12/13)
The invention relates to a method for preparing a combretastatin derivative (I) or (II), said method including the following steps: triaryl(3,4,5-trimethoxybenzyl)phosphonium halide P3 (III), wherein Ar denotes an aryl group selected from among phenyl or thienyl, is reacted with P2 having formula (IV) or P′2 having formula (V) so as to respectively obtain the compound P4 or P′4, which have formulas (VI) and (VII), respectively; then, during a step for deprotection in the presence of an acid and/or a base, the compound having P4 or P′4 leads, after an optional purification step, to the compound having formula (I) or (II).
Supported bilayer lipid membrane arrays on photopatterned self-assembled monolayers
Han, Xiaojun,Pradeep, Singh N. D.,Critchley, Kevin,Sheikh, Khizar,Bushby, Richard J.,Evans, Stephen D.
, p. 7957 - 7964 (2008/04/01)
This work demonstrates the use of photocleavable cholesterol derivatives to create supported bilayer lipid membrane arrays on silica. The photocleavable cholesteryl tether is attached to the surface by using the reaction of an amine-functionalized self-assembled monolayer (SAM) and the N- hydroxysuccinimide-based reagent 9. The resultant SAM contains an orthonitrobenzyl residue that can be cleaved by photolysis by using soft (365 nm) UV light regenerating the original amine surface, and which can be patterned using a mask. The photoreaction yield was ≈75% which was significantly higher than previously found for related ortho-nitrobenzyl photochemistry on gold substrates. The SAMs were characterized by means of contact angle measurements, ellipsometry and X-ray photoelectron spectroscopy. Patterned surfaces were characterized with SEM and AFM. After immersing the patterned surface into a solution containing small unilamellar vesicles of egg phosphatidylcholine (PC), supported lipid membranes were formed comprised of lipid bilayer over the amine functionalized "hydrophilic" regions and lipid monolayer over the cholesteryl "hydrophobic" regions. This was confirmed by fluorescence microscopy and AFM. FRAP studies yielded a lateral diffusion coefficient for the probe molecule of 0.14±0.05 μm 2s-1 in the bilayer regions and ≈0.01 μm 2s-1 in the monolayer regions. This order of magnitude difference in diffusion coefficients effectively serves to isolate the bilayer regions from one another, thus creating a bilayer array.
Enantioselective total synthesis of the fungicide β-lactam antibiotic (-)-(2S,5S)-2-(2-hydroxyethyl)clavam and its (+)-(2S,5R)-epimer
Hoppe,Hilpert
, p. 2467 - 2474 (2007/10/02)
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