Decreased l-tryptophan concentration in distinctive brain regions of mice treated repeatedly with phencyclidine

It has been reported that repeated phencyclidine (PCP) treatment induces schizophrenia-like behavior in mice. l-Tryptophan (Trp) concentrations in brain tissues of control (n?=?8) and PCP-treated mice (10 mg/kg/day, s.c., 14 days, n?=?10) were determined using high-performance liquid chromatography (HPLC) with fluorescence detection. The HPLC method involved pre-column fluorescence derivatization with (R)-(?)-4-(N,N-dimethylaminosulfonyl)-7-(3-isothiocyanatopyrrolidin-1-yl)-2,1,3-benzoxadiazole (DBD-PyNCS). Eight different parts of the brain, namely, the frontal cortex, nucleus accumbens, striatum, hippocampus, amygdala, thalamus, hypothalamus, and cerebellum, of both groups were investigated. A significant decrease in the l-Trp concentration in the nucleus accumbens (p?=?0.024) and hippocampus (p?=?0.027) was observed in PCP-treated mice, suggesting that alteration of the l-Trp metabolism might occur in these brain parts.     

A Synthetic Method for Preparing 3,3-Dialkyl-1,2,3,8-tetrahydroazulen-1-one

The trimethylsilyl enol ether of l-acetylcyclohepta-1,3,5-triene was transformed to 3,3-dialkyl-1,2,3,8-tetrahydroazulen-1-one by a two-step sequence involving the Mukaiyama aldol reaction with ketones and the subsequent Nazarov cyclization.     

Synthesis of chiral 2-(anilinophenylmethyl)pyrrolidines and 2-(anilinodiphenylmethyl)pyrrolidine and their application to enantioselective borane reduction of prochiral ketones as chiral catalysts

Chiral diamines, 2-(anilinophenylmethyl)pyrrolidines and 2-(anilinodiphenylmethyl)pyrrolidine, were prepared from N-(tert-butoxycarbonyl)pyrrolidine or (S)-proline as a starting material, respectively. These chiral diamines were efficient for the catalytic enantioselective borane reduction of acetophenone. Using (S)-2-(anilinodiphenylmethyl)pyrrolidine, chiral secondary alcohols were obtained from prochiral ketones with good to excellent enantiomeric excesses (up to 98% ee).     

Conformation and Atropisomeric Properties of Indometacin Derivatives

The stereochemistry around the N‐benzoylated indole moiety of indometacin was studied by restricting the rotation about the N? C7′ and/or C7′? C1′ bond. In the 2′,6′‐disubstituted ones, an atropisomeric property was found and the atropoisomers were separated and isolated as stable forms. Their biological abilities to inhibit cyclooxygenase‐1 (COX‐1) and cyclooxygenase‐2 (COX‐2) were examined. Only the aR‐isomer showed specific inhibition of COX‐1, and COX‐2 was not inhibited by either atropisomer. Conformational analysis in NMR studies and X‐ray crystallography, and CD spectra in combination with calculations were utilized to elucidate the bioactive conformations.     

Application of ZnO nanoparticles to enhance the antimicrobial activity and ultraviolet protective property of bamboo pulp fabric

Hyperbranched polymer HSDA was synthesized from methyl acrylate, tetraethylenepentamine, and dodecanoic acid by melt polycondensation. ZnO nanoparticle colloidal solution was prepared in one step by mixing Zn(NO₃)₂ and HSDA aqueous solution under hydrothermal condition. The results of transmission electron microscopy and ultraviolet–visible (UV–Vis) spectroscopy indicated that ZnO nanoparticles were formed in colloidal solution. Bamboo pulp fabric was treated with ZnO nanoparticle colloidal solution by an impregnation method to provide the bamboo pulp fabric with antibacterial and UV protective properties. The whiteness, antibacterial activity, UV protective property, and washing durability of the ZnO nanoparticle-treated fabrics were determined. The results indicated that the bamboo pulp fabric treated with ZnO nanoparticles showed good UV protective properties and its ultraviolet protection factor (UPF) can reach 90.38. The UPF value of treated fabric drops to 70.42 after washing for 20 times, but it retains good UV protective properties. The ZnO nanoparticle-treated fabric showed 99.91 % bacterial reduction of Staphylococcus aureus and 99.97 % bacterial reduction of Escherichia coli. The fabric retained over 98.93 % reduction level even after being exposed to 20 consecutive home-laundering conditions. In addition, the results of scanning electron microscopy and X-ray spectroscopy confirmed that ZnO nanoparticles were fixed and well dispersed on bamboo pulp fabric.     

Synthesis of chlorophyll-a derivatives possessing (un)substituted 13-exo-methylene moiety and their optical properties

Chlorophyll-a derivatives possessing an un/mono/disubstituted methylene moiety at the 13¹-position were prepared by (un)substituted methylation of the 13-carbonyl group and successive dehydration. Substitution of the 13¹-oxo to the methylene group slightly blue-shifted electronic absorption and emission bands in a solution and decreased chemical stability to give an oxidation product cleaved at the E-ring. Further mono/disubstitution at the methylene terminal increased wavelengths of absorption and emission maxima as well as oxidative tolerance.     

Oxidative Bond Cleavage of the Silicon–Silicon Bond of a Pentacoordinated Disilicate

The Si Si bond of a pentacoordinated disilicate was readily cleaved by treatment with 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone in the presence of sodium carbonate under mild conditions. The bond cleavage did not proceed under the same conditions after conversion of the disilicate into the corresponding monoanionic silylsilicate and neutral disilane by protonation. The difference in the charges of the Si Si bond compounds affects the reactivity toward an oxidant, resulting in the Si Si bond cleavage, considering that all of these compounds have a bond between pentacoordinated silicon atoms.     

Synthesis,characterization and bio-activity of a bidentate NS Schiff base of S-allyldithiocarbazate and its divalent metal complexes: X-ray crystal structures of the free ligand and its nickel(II) complex

Transition metal complexes ML₂ (2–6) [where M = Ni(II), Cu(II), Zn(II), Cd(II), Pd(II) and HL = allyl-2-(4-benzyloxyphenylmethylene)hydrazine carbodithioate (1)] have been prepared by the reaction of the ligand with metal ions in 2:1 molar ratio and characterized by physicochemical techniques and spectroscopic methods. The crystal structures of the free ligand and its nickel(II) complex 2 have been determined by X-ray diffractometry. The ligand exists in its thione tautomeric form both in solution and in the solid state. In complex 2, square-planar coordination of nickel(II) was achieved by two chelating ligand moieties coordinating through the azomethine nitrogen and the deprotonated thione sulphur atom. Based on the crystal structures of analogous dithiocarbazate species, a square-planar geometry was assumed for the copper(II) and palladium(II) complexes, and a tetrahedral coordination sphere for the zinc(II) and cadmium(II) derivatives. The in vitro bactericidal activity suggests that the palladium(II) complex is strongly active against two bacteria. The cadmium(II) complex is moderately cytotoxic with an LC₅₀ value of 409 μg/ml, but less active than gallic acid, LC₅₀ = 78 μg/ml.     

Biosynthesis of Indole Diterpene Lolitrems: Radical‐Induced Cyclization of an Epoxyalcohol Affording a Characteristic Lolitremane Skeleton

Lolitrems are tremorgenic indole diterpenes that exhibit a unique 5/6 bicyclic system of the indole moiety. Although genetic analysis has indicated that the prenyltransferase LtmE and the cytochrome P450 LtmJ are involved in the construction of this unique structure, the detailed mechanism remains to be elucidated. Herein, we report the reconstitution of the biosynthetic pathway for lolitrems employing a recently established genome‐editing technique for the expression host Aspergillus oryzae. Heterologous expression and bioconversion of the various intermediates revealed that LtmJ catalyzes multistep oxidation to furnish the lolitrem core. We also isolated the key reaction intermediate with an epoxyalcohol moiety. This observation allowed us to establish the mechanism of radical‐induced cyclization, which was firmly supported by density functional theory calculations and a model experiment with a synthetic analogue.