Towards clinical proteomics analysis

To understand accurate protein dynamics, a highly reproducible proteomics analytical method is required. The acquired thus knowledge will lead to the diagnosis, treatment and protection against diseases. This review deals with proteomics analysis from a view of sample pre-treatment, sensitivity and reproducibility of the methods, including two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), liquid chromatography-tandem mass spectrometry (LC-MS/MS). and fluorogenic derivatization (FD)-LC-MS/MS.     

Stereocontrolled synthesis of substituted chiral piperidines via one-pot asymmetric 6π-azaelectrocyclization: asymmetric syntheses of (-)-dendroprimine, (+)-7-epidendroprimine, (+)-5-epidendroprimine, and (+)-5,7-epidendroprimine

The asymmetric one-pot 6π-azaelectrocyclization of alkenyl vinyl stannane, ethyl (Z)-2-iodo-4-oxobutenoate, and (-)-7-isopropyl-cis-aminoindanol in the presence of a Pd(0) catalyst stereoselectively produced the tetracyclic aminoacetal compounds, resulting from the four-bond formation accompanying by controlling the stereochemistry at the two asymmetric centers. The produced cyclic aminoacetals can be regarded as synthetic precursors of substituted chiral piperidines, and the syntheses of 2,4- and 2,4,6-substituted piperidines were realized from the obtained aminoacetals by the stereoselective hydrogenation of the double bond conjugated with the C-4 ester group and alkylation at the aminoacetal moiety. In addition, the stereoselective synthesis of an indolizidine alkaloid, (-)-dendroprimine, and its three stereoisomers, (+)-7-epidendroprimine, (+)-5-epidendroprimine, and (+)-5,7-epidendroprimine, were achieved.     

A Boryl‐Substituted Diphosphene: Synthesis,Structure, and Reaction with n‐Butyllithium To Form a Stabilized Adduct by pπ‐pπ Interaction

A boryl‐substituted diphosphene was synthesized through the nucleophilic borylation of PCl₃ with a borylzinc reagent, followed by a reduction with Mg. A combined analysis of the resulting diboryldiphosphene by single‐crystal X‐ray diffraction, DFT calculations, and UV/Vis spectroscopy revealed a σ‐electron‐donating effect for the boryl substituent that was slightly weaker than that of the 2,4,6‐tri‐tert‐butylphenyl (Mes*) ligand. The reaction of this diboryldiphosphene with ⁿBuLi afforded a boryl‐substituted phosphinophosphide that was, in comparison with the thermally unstable Mes*‐substituted diaryldiphosphene, stabilized by a π‐electron‐accepting effect of the boryl substituent.     

Highly reactive “RIKEN click” probe for glycoconjugation on lysines

One pot double click strategy containing strain-promoted click-reaction followed by 6π-azaelectrocyclization (RIKEN click reaction) has worked well in the synthesis of multivalent homogeneous and heterogeneous N-glycoalbumins. We have slightly changed the structure of linker unsaturated aldehyde used in this method. As a result it can be easily synthesized from commercially available material and furthermore, the enhancement of its reactivity towards both click-reactions was observed. The data described in this Communications facilitate the usage of the double click strategy as a general method for the synthesis of a variety of neo-N-glycoproteins.     

Erratum to: Sources of 137Cs fluvial export from a forest catchment evaluated by stable carbon and nitrogen isotopic characterization of organic matter

Journal of Radioanalytical and Nuclear Chemistry -     

Optical noise reduction for dc-removed coaxial holographic data storage

A method of reconstructing positive and negative images from Fourier holograms recorded without the dc components is demonstrated by use of a coaxial holographic storage system. Reconstructed images are obtained by adding a phase-modulated dc component of the signal beam on reading. Contrast reversal of the reconstructed images can be achieved by reversing the readout reference pattern. This method can realize not only optical noise reduction but also less consumption of the dynamic range of the recording medium, potentially contributing to increasing the number of multiplexed holograms.     

Synthesis of unsymmetrically substituted 2,2'-dihydroxy-1,1'-biaryl derivatives using organic-base-catalyzed Ferrier-type rearrangement as the key step

A strong organic base, TBD, functioned as a unique catalyst for the intramolecular multi-step transformation of lactols using the Ferrier-type rearrangement as the key step to provide unsymmetrically substituted 2,2'-dihydroxy biaryl compounds having four ortho substituents about the biaryl axis without the need for a metal catalyst.     

Triangular C1-bialgebra defined as the direct sum of matrix algebras

Let $M_{*}(\mathbf{C})$ denote the ${\mathrm{C}}^1$-algebra defined as the direct sum of all matrix algebras $\{M_n(\mathbf{C}):n?1\}$. It is known that $M_{*}(\mathbf{C})$ has a non-cocommutative comultiplication ${\mathrm{\Delta }}_{\phi }$. From a certain set of transformations of integers, we construct a universal R-matrix R of the ${\mathrm{C}}^1$-bialgebra $(M_{*}(\mathbf{C})\text{,}{\mathrm{\Delta }}_{\phi })$ such that the quasi-cocommutative ${\mathrm{C}}^1$-bialgebra $(M_{*}(\mathbf{C})\text{,}{\mathrm{\Delta }}_{\phi }\text{,}R)$ is triangular. Furthermore, it is shown that certain linear Diophantine equations are corresponded to the Yang–Baxter equations of R.