On Ocneanu's theory of double triangle algebras for subfactors and classification of irreducible connections on the Dynkin diagrams

We give an exposition of Ocneanu's theory of double triangle algebras for subfactors and its application to the classification of irreducible bi-unitary connections on the Dynkin diagrams _An$A_n$, _Dn$D_n$, _E6$E_6$, _E7$E_7$ and _E8$E_8$. More precisely, we give a detailed proof of the complete classification of irreducible K–L$K–L$ bi-unitary connections up to gauge choice, where K and L   represent the two horizontal graphs which are among the A–D–E$A–D–E$ Dynkin diagrams. The result also provides a simple proof of the flatness of _D2n$D_{2n}$, _E6$E_6$ and _E8$E_8$ connections as well as an easy computation of the flat part of _E7$E_7$ as an application.     

Platinum(II) complex-catalyzed enantioselective aldol reaction with ketene silyl acetals in DMF at room temperature

[{(R)-binap}Pt(μ-OH)]₂2X is a weak Lewis acid, which can catalyze the enantioselective aldol reaction of aldehydes with ketene silyl acetals in DMF at room temperature. The platinum(II) complex-catalyzed the enantioselective aldol reaction of aldehydes with 1-methoxy-2-methyl-(1-trimethylsilyloxy)propene gave the corresponding aldols in high yields with enantioselectivity up to 92%. With 5 mol % loading of the complexes, the enantioselective aldol reaction of aldehydes with 1-benzyloxy-1-(trimethylsilyloxy)propene smoothly proceeded in DMF containing 10% HMPA as to predominantly give anti-propionates with enantioselectivity up to 89%, irrespective of the silyl nucleophile geometry.     

Synthesis and DNA cleavage evaluation of epoxypiperidine derivatives bearing a dehydroamino acid unit

Epoxypiperidine derivatives bearing a dehydroamino acid unit were designed and synthesized as novel DNA alkylating agents based on the structure of azinomycins. A relaxation assay of plasmid DNA revealed that the epoxypiperidine derivative 3 has a DNA cleavage activity. Based on the studies, it would appear that the electron density of the amino group of epoxypiperidines plays a critically important role in the DNA cleavage.     

Intramolecular titanium-promoted deoxygenative cyclization to 9-substituted-1,2,3,4-tetrahydrofluorene skeleton

The Mukaiyama aldol reaction of 2-aryl-1-cyclohexene-1-carboxaldehydes with phenyl trimethylsilyl ketene acetal unexpectedly resulted in the formation of 9-substituted-1,2,3,4-tetrahydrofluorene derivatives via a novel intramolecular titanium-promoted deoxygenative cyclization. By successive treatment of the corresponding allyl alcohols with n-butyllithium and titanium tetrachloride, the cyclization products were obtained in good yields.     

Design and synthesis of functionalized trisaccharides as p53-peptide mimics

Oligosaccharides represent potentially useful scaffolds for the development of peptidomimetics. We report here the design and synthesis of functionalized trisaccharides modeled after an α-helical 15-mer peptide region of p53 which binds to its cellular regulator MDM2. The trisaccharide scaffold was obtained efficiently by applying the sulfoxide glycosylation reaction as a key methodology.     

Characterization of biosynthesized P(3HB-co-3HA)s swellable in organic solvents

Polyhydroxyalkanoate (PHA) copolymers consisting of (R)-3-hydroxybutyrate (3HB) and medium-chain-length (R)-3-hydroxyalkanoate (3HA), P(3HB-co-3HA), are usually solved in chloroform. However, we found that some of the P(3HB-co-3HA) aged for more than 1 month under ambient conditions were not solved in chloroform, but instead swelled when the 3HA fraction was over 14 mol%. On the basis of differential scanning calorimetry and wide-angle x-ray diffraction analyses, we predicted that swellable P(3HB-co-3HA) contained numerous P(3HB) microcrystals, which may form physical crosslinks between adjacent PHA polymer chains.     

The development of a knowledge base for basic active structures: an example case of dopamine agonists

Background  

Chemical compounds affecting a bioactivity can usually be classified into several groups, each of which shares a characteristic substructure. We call these substructures "basic active structures" or BASs. The extraction of BASs is challenging when the database of compounds contains a variety of skeletons. Data mining technology, associated with the work of chemists, has enabled the systematic elaboration of BASs.     

MassBank: a public repository for sharing mass spectral data for life sciences

MassBank is the first public repository of mass spectra of small chemical compounds for life sciences (<3000 Da). The database contains 605 electron‐ionization mass spectrometry(EI‐MS), 137 fast atom bombardment MS and 9276 electrospray ionization (ESI)‐MSⁿ data of 2337 authentic compounds of metabolites, 11 545 EI‐MS and 834 other‐MS data of 10 286 volatile natural and synthetic compounds, and 3045 ESI‐MS² data of 679 synthetic drugs contributed by 16 research groups (January 2010). ESI‐MS² data were analyzed under nonstandardized, independent experimental conditions. MassBank is a distributed database. Each research group provides data from its own MassBank data servers distributed on the Internet. MassBank users can access either all of the MassBank data or a subset of the data by specifying one or more experimental conditions. In a spectral search to retrieve mass spectra similar to a query mass spectrum, the similarity score is calculated by a weighted cosine correlation in which weighting exponents on peak intensity and the mass‐to‐charge ratio are optimized to the ESI‐MS² data. MassBank also provides a merged spectrum for each compound prepared by merging the analyzed ESI‐MS² data on an identical compound under different collision‐induced dissociation conditions. Data merging has significantly improved the precision of the identification of a chemical compound by 21–23% at a similarity score of 0.6. Thus, MassBank is useful for the identification of chemical compounds and the publication of experimental data. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of mesoporous PtCu film modified with Ru submonolayer as catalyst for methanol electrooxidation

A mesoporous PtCu catalyst modified with a Ru submonolayer is successfully synthesized by a facile electrochemical process of electrodeposition, dealloying and Ru underpotential deposition. The material has a large specific surface area comparable to nanoparticles (11 m(2) g(-1)) and exhibits a promising catalyst activity for the methanol oxidation reaction.     

Modification of flexible part in Cu(2+) interdigitated framework for CH(4)/CO(2) separation

The structural flexibility of Cu(2+) interdigitated layer type framework was controlled and the compound represented clear separation property of CH(4)/CO(2) at range of 0-1.0 MPa and recovery of adsorbed CO(2) above 0.1 MPa.