Optimization of in-gel protein digestion system in combination with thin-gel separation and negative staining in 96-well plate format

Improvement of in-gel digestion efficiency is highly desirable for one- or two-dimensional gel electrophoretic separation and mass spectrometric (MS) analysis in proteomics, because the resultant increases in sequence coverage and MS signal intensity lead to higher confidence in protein identification. Here an optimized in-gel digestion system, in combination with thin-gel separation and negative staining in a high-throughput format using 96-well plates, is described. The combination of negative staining and protein separation on a 0.9 mm thick gel showed a clear improvement in in-gel digestion efficiency in comparison with the more typical protocols such as the combination of silver staining and a 1.0 mm gel. In addition, the use of 96-well plates to increase throughput did not decrease the efficiency of this strategy when the stirring of the gel pieces in processes such as destaining, washing, gel-shrinking and peptide extraction was performed by sonication instead of shaking the plates. This procedure was optimized and applied to identify proteins of the postsynaptic density fraction; 105 proteins were identified after SDS-PAGE separation.     

Catalytic asymmetric desymmetrization of cyclic meso-1,3- and 1,4-diols by a phosphinite derivative of quinidine

Asymmetric monobenzoylation reactions of cyclic meso-1,3- and 1,4-diols were catalyzed by a phosphinite derivative of quinidine to afford the corresponding monobenzoylated diol with good yield and enantioselectivity. [reaction: see text]     

Dynamic stability of carbonyl ylides

The non- and fluorine-substituted singlet carbonyl ylides are studied by using ab initio MCSCF calculations. The thermodynamic stability of the carbonyl ylides and the intramolecular stability to isomerization or fragmentation reaction coordinates is demonstrated in terms of the topological structure of the ab initio potential energy surfaces. The allylic resonance is found to be dynamically unstable, considering out-of-plane vibrational mode. The instability is studied by the symmetries of the low-lying excitations out of the MCSCF wave function.     

Direct conversion of allylic alcohols into N-acyl-α-amino acids by catalytic amidocarbonylation by means of homogeneous binary systems

N-Acyl-α-amino acids are synthesized by the amidocarbonylation of allylic alcohols catalyzed by homogeneous binary systems which consist of cobalt carbonyl and rhodium (or iron or palladium) complexes.     

Synthesis of inorganic-organic hybrids by incorporation of inorganic components into organic polymer using metal alkoxides

Inorganic-organic hybrids have been synthesized by incorporation of the inorganic component of Ti(OC₂H₅)₄ into the organic polymer of ethyl cellulose. The inorganic-organic hybrids did not dissolve in toluene used as a solvent for the starting materials. The ethanol was formed as a by-product of the alcoholysis condensation reaction between Ti(OC₂H₅)₄ and ethyl cellulose. These results suggest that ethoxy groups of Ti(OC₂H₅)₄ react with hydroxy groups of ethyl cellulose to form cross-linking bonds of –O–Ti–O–. The reaction of Ti(OC₂H₅)₄ with ethyl cellulose was further investigated by Fourier transform infrared (FT-IR) spectroscopy. The FT-IR spectroscopic experiments revealed that the Ti–O bond state of Ti(OC₂H₅)₄ was changed by refluxing a toluene solution of Ti(OC₂H₅)₄ with ethyl cellulose. The inorganic-organic hybrids have an interesting dielectric property; their dielectric constant is higher than that of ethyl cellulose and that of a simple mixture of TiO₂ and ethyl cellulose.