Nanoacorns: anisotropically phase-segregated CoPd sulfide nanoparticles

The anisotropically phase-segregated CoPd sulfide nanoparticles, named "CoPd nanoacorns", were spontaneously generated by reducing the corresponding metal precursors with 1,2-hexadecanediol in the presence of various alkanethiols. The CoPd nanoacorn consisting of crystalline Co9S8 and amorphous PdSx phases with the Co9S8 (001) plane at their interface was found to spontaneously form through the anisotropic growth of the Co9S8 phase after the generation of PdSx nanoparticles.     

Vinylpolymerisation. 283. Mitt

Ohne Zusammenfassung     

Polycyclic N-Heterocyclic compounds. 50. Synthesis and pharmacological evaluation of 2,3,6,7-Tetrahydrothieno[2,3-H]-imidazo[2,1-f][1,6]naphthyridines,3,4,7,8-Tetrahydro-2H-thieno-[2,3-h]pyrimido[2,1-f][1,6]naphthyridines and their precursor

Some novel 5-hydroxyalkylamino-1,2-dihydrothieno[2,3-h][1,6]naphthyridines were prepared by the reaction of 5-chloro-1,2-dihydrothieno[2,3-h][1,6]naphthyridine derivatives with some aminoalcohols in the presence of base. These derivatives were cyclized to the corresponding imidazo or pyrimido derivatives. The bronchodilatory activity of these compounds was evaluated on the basis of their relaxation activity to tracheal contraction induced by carbamylcholine chloride as a primary in vitro assays. Effect of some naphthyridines on carbamylcholine chloride-induced contractions of trachea in the presence or absence of milrinone or 4-(3-butoxy-4-methoxyphenyl)imidazolidin-2-one, which is inhibitor of phosphodiesterase III or IV, were also evaluated.     

Expression of a model peptide of a marine mussel adhesive protein in Escherichia coli and characterization of its structural and functional properties

An expression system for a chemically synthesized gene, encoding a model peptide of marine mussel adhesive protein, was constructed in Escherichia coli under regulation of the T7‐promoter. The model peptide consisted of six repeats of the decapeptide AKPSYPPTYK. Although the product was expressed as an inclusion body, we were able to solubilize it successfully, using acetic acid. The higher‐order structure of this model peptide was investigated using CD spectroscopy and NMR spectroscopy. Using the modified enzyme, mushroom tyrosinase, the tyrosine residue was hydroxylated to 3,4‐dihydoxyphenylalanine (Dopa), and the resulting modified peptide was polymerized, solidified, and insolubilized spontaneously. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 729–736, 1999     

Synthesis of comb-like polyurethanes containing hydrophilic phosphatidylcholine analogues in the main chains and hydrophobic long chain alkyl groups in the side chains

Three new amphiphilic phospholipid diols containing hydrophilic phosphatidylcholine analogues in the main chains and hydrophobic octadecyl, hexadecyl or dodecyl alkyl groups in the side chains were synthesized. The typical phospholipid diol based on an octadecyl group was further reacted with diisocyanates such as hexamethylene diisocyanate (HDI), 2,4-tolylene diisocyanate (TDI) and 4,4′-methylenediphenyl diisocyanate (MDI), respectively. Preliminary studies suggest that polyurethane based on MDI shows a viscosity behavior similar to common polyelectrolytes and exhibits a therm decomposition peak at 244°C due to the phospholipid moiety and a melting point at 218°C.     

Iridium complex-catalyzed highly selective cross [2 + 2 + 2] cycloaddition of two different monoynes: 2:1 coupling versus 1:2 coupling

[reaction: see text] Highly selective cross [2 + 2 + 2] cycloaddition of two different monoynes is achieved by using a catalytic amount of [Ir(cod)Cl](2) and ligand. The ligand had a considerable effect on the reaction. When 1,2-bis(diphenylphosphino)ethane was used, two molecules of dimethyl acetylenedicarboxylate (DMAD) reacted with one molecule of a monoyne to give the 2:1 coupling product. When 1,2-bis(dipentafluorophenylphosphino)ethane was used instead of dppe, one molecule of DMAD reacted with two molecules of a monoyne to give the 1:2 coupling product.     

Four New Stilbene Oligomers in the Root of Gnetum gnemon

Four new stilbene oligomers, gnemonols G, H, I, and J ( 1 – 4 ), were isolated from acetone extract of the root of Gnetum gnemon along with five known stilbenoids, ampelopsin E, cis‐ampelopsin E, gnetins C, D, and E. The structures were elucidated on the basis of spectroscopic evidence.     

Two New Resveratrol (=5‐[(1E)‐2‐(4‐Hydroxyphenyl)ethenyl]benzene‐1,3‐diol) Tetramers with a Tetrahydrofuran Ring from Dipterocarpus grandiflorus

Two new stilbene tetramers, grandiphenols A ( 1 ) and B ( 2 ), along with ten known stilbene oligomers and bergenin were isolated from the stem of Dipterocarpus grandiflorus. The structures of 1 and 2 composed of four resveratrol (=5‐[(1E)‐2‐(4‐hydroxyphenyl)ethenyl]benzene‐1,3‐diol) units had eight asymmetric C‐atoms in the partial structures of a tetrahydrofuran and two dihydrobenzofuran moieties. Detailed spectroscopic analyses, especially HMBC and NOESY experiments, allowed to differentiate the configurations of 1 and 2 .