Isothermal gas chromatographic determination of nanogram amounts of chlorimipramine, chlorpromazine and their N-desmethyl metabolites in plasma using nitrogen-selective detection

A gas chromatographic method using nitrogen-selective detection for the quantitative determination of nanogram amounts of chlorimipramine, chlorpromazine and their nor1 and nor2 derivatives in plasma is described. Derivatization with trifluoroacetic anhydride of nor1 and nor2 metabolites allowed the chromatographic separation of these compounds. A three-step solvent extraction procedure was performed using n-heptane containing 1% isoamyl alcohol and n-hexane and compared with a plasma clean-up procedure using C18 Sep-Pak cartridges. The two procedures were characterized by similar degrees of precision. The use of C18 Sep-Pak cartridges, however, produced a significant time and material saving over the conventional extraction method.     

Generation of genealogical spin eigenfunctions

A method is given for generating the Yamanouchi-Kotani genealogical spin eigenfunctions which requires neither storage of eigenfunctions for smaller numbers of electrons, nor summations of large order, nor explicit use of results from the theory of representations of the symmetric group. An explicit formula is given for the coefficients of expansion in terms of spin products.     

Dispersion Forces,Disproportionation, and Stable High‐Valent Late Transition Metal Alkyls

The transition metal tetra‐ and trinorbornyl bromide complexes, M(nor)₄ (M=Fe, Co, Ni) and Ni(nor)₃Br (nor=1‐bicyclo[2.2.1]hept‐1‐yl) and their homolytic fragmentations were studied computationally using hybrid density functional theory (DFT) at the B3PW91 and B3PW91‐D3 dispersion‐corrected levels. Experimental structures were well replicated; the dispersion correction resulted in shortened M?C bond lengths for the stable complexes, and it was found that Fe(nor)₄ receives a remarkable 45.9 kcal mol^?1 stabilization from the dispersion effects whereas the tetragonalized Co(nor)₄ shows stabilization of 38.3 kcal mol^?1. Ni(nor)₄ was calculated to be highly tetragonalized with long Ni?C bonds, providing a rationale for its current synthetic inaccessibility. Isodesmic exchange evaluation for Fe(nor)₄ confirmed that dispersion force attraction between norbornyl substituents is fundamental to the stability of these species.     

Dispersion Forces,Disproportionation, and Stable High‐Valent Late Transition Metal Alkyls

The transition metal tetra‐ and trinorbornyl bromide complexes, M(nor)₄ (M=Fe, Co, Ni) and Ni(nor)₃Br (nor=1‐bicyclo[2.2.1]hept‐1‐yl) and their homolytic fragmentations were studied computationally using hybrid density functional theory (DFT) at the B3PW91 and B3PW91‐D3 dispersion‐corrected levels. Experimental structures were well replicated; the dispersion correction resulted in shortened M−C bond lengths for the stable complexes, and it was found that Fe(nor)₄ receives a remarkable 45.9 kcal mol⁻¹ stabilization from the dispersion effects whereas the tetragonalized Co(nor)₄ shows stabilization of 38.3 kcal mol⁻¹. Ni(nor)₄ was calculated to be highly tetragonalized with long Ni−C bonds, providing a rationale for its current synthetic inaccessibility. Isodesmic exchange evaluation for Fe(nor)₄ confirmed that dispersion force attraction between norbornyl substituents is fundamental to the stability of these species.     

无催化剂条件下环辛烯环氧化反应的研究

以氧气为氧源,在无溶剂无引发剂条件下,研究了非催化剂体系中环辛烯环氧化反应,并考察了反应温度、时间、压力、自由基引发剂以及自由基阻聚剂对环辛烯环氧化反应的影响。实验结果表明,在无催化剂条件下,当反应压力0.60MPa,反应时间2.0 h时,在140℃的较高温度下,以分子氧为氧源,环辛烯的转化率为44.46%,环氧环辛烷的选择性可达到64.39%。     

Synthesis of N,N‐Dialkylamino‐nor‐Dihydroxanthene‐Hemicyanine Fused Near‐Infrared Fluorophores and Their First Water‐Soluble and/or Bioconjugatable Analogues

The effective synthesis of extended conjugated N ,N ‐dialkylamino‐nor ‐dihydroxanthene‐based fluorophores is described from diversely functionalized salicylic aldehydes. The access to these original fluorescent derivatives proceeded in two steps through a one‐pot construction of the unusual nor ‐dihydroxanthene (nor ‐DHX) scaffold followed by a diversification step providing a wide variety of nor ‐DHX‐hemicyanine fused dyes emitting in the range of 730–790 nm. The versatility of our approach has enabled a further extension to the late‐stage introduction of negatively/positively charged polar groups onto their terminal nitrogen heterocyclic subunit, thereby giving access to the first water‐soluble and/or bioconjugatable members of this emerging class of NIR fluorophores. Our water‐solubilizing method is easily implementable, and the nor ‐DHX‐hemicyanine skeleton maintains satisfying fluorescence quantum yields (5–20 %) under physiological conditions. Finally, the bioconjugation ability of fluorescent derivatives bearing a free carboxylic acid was demonstrated through the covalent labeling of a model protein, namely, bovine serum albumin.     

The action of norfloxacin complexes on Tetrahymena investigated by microcalorimetry

Cu(nor)₂·H₂O (1), Zn(nor)₂·4H₂O (2), Ni(nor)₂·2H₂O (3), [Cu(nor)(phen)]NO₃·4H₂O (4), [Zn(nor)(phen)]NO₃·2H₂O (5), and [Ni(nor)(phen)]NO₃·3H₂O (6) were synthesized and their action on Tetrahymena growth was studied by microcalorimetry. The growth constant (k), inhibitory ratio (I), and half-inhibiting concentration (IC₅₀) were calculated, which showed that the complexes had a strong inhibitory effect on Tetrahymena. All these complexes can inhibit the growth of Tetrahymena more strongly than norfloxacin. The norfloxacin?Cmetal complexes exhibited better inhibitory activity than nor?Cphen?Cmetal complexes. The power?Ctime curves of Tetrahymena growth in the presence of norfloxacin were also measured. It was found that all complexes showed higher inhibitory activity than norfloxacin. And the inhibitory mechanism was discussed preliminarily. The diverse inhibition may be due to the ability of the complexes to penetrate into cells and the effect of these complexes on the nucleic acid. Microcalorimetry has been used extensively in many biological and chemical investigations as a universal, non-destructive, continuously running, and highly sensitive tool.     

Effect of metal ions in organic synthesis. Part XIV. A mild,simple, and convenient method for the synthesis of 1-(arylamino)pyrrole derivatives by copper(II) ion-catalyzed reaction of (arylazo)alkenes and 1,3-dicarbonyl compounds

A mild, simple and convenient method for the synthesis of some 1-(arylamino)pyrrole derivatives by copper(II) ion-catalyzed reaction of (arylazo)alkenes and 1, 3-dicarbonyl compounds is reported. These reactions take place under magnetic stirring at room temperature, do not require a strong acid or base, nor expensive or difficultly available reagents, nor even complicated procedures. The synthesis seems to be successfully applicable to different (arylazo)alkenes, 1, 3-diketones and ß-ketoesters, and frequently occurs with good yields.     

A New Triterpene and New Sesquiterpenes from the Roots of Ligularia sagitta

One new triterpene and seven new eremophilane‐type sesquiterpenes were isolated from the roots of Ligularia sagitta, among them 1a , an O‐acetylated oleanane type triterpene, 2a and 3a , two 11‐nor eremophilane‐type sesquiterpenes, 4a, 5 , and 6 , three standard eremophilane‐type sesquiterpenes, and 7 and 8 , two tri‐nor eremophilane‐type sesquiterpenes. Their structures were established by extensive spectral analyses (1D, 2D‐NMR, IR, and MS). Compound 1a showed moderate cytotoxicity against two tumor cell lines.     

Direct use of allylic alcohols in the allylation of sulfonylimidates

We have developed catalytic allylation reactions of sulfonylimidates using allylic alcohols as allylating reagents. Stoichiometric amounts of neither activators nor bases are required in this reaction.     

4-Iodo-2-methyl-5-nitro­aniline exhibits neither strong hydrogen bonding nor intermolecular I⃛nitro interactions

In the title compound, C₇H₇IN₂O₂, the O atoms of the nitro group are disordered over two sets of sites and there is evidence that the intramolecular I⃛nitro interaction is repulsive. In the crystal structure, there are neither strong hydrogen bonds, nor intermolecular I⃛nitro interactions, nor aromatic π–π-stacking interactions.     

Preparation and benchmarking of novel cellulose nanopaper

Cellulose - Synthetic polymers and plastics which are currently used as barrier materials in packaging applications are neither renewable nor biodegradable. Nanopaper, which is obtained by breaking...     

Simulation study of intra- and intermicellar ordering in triblock-copolymer systems

We report a numerical study of the structure and phase behavior of a model for a triblock-copolymer solution. The aim of this study is to investigate the nature of the dense micellar phase that can form in such systems. The simulations were performed on a lattice model for PEO (poly(ethylene-oxide))-PPO (poly(propylene-oxide))-PEO polymers. At high volume fractions, the structure factor of the amphiphile-solvent system can be mapped onto that of a monodisperse hard-sphere fluid. Yet, a low-density hard-sphere model cannot account for the properties of the dilute micellar solution. Moreover, direct inspection of the snapshots of the suspension show that these model triblock-copolymer micelles are neither hard, nor spherical, nor monodisperse.     

Solvent-Free Synthesis of Thiophenol Using Uncatalyzed Transfer Hydrogenation

Clean and sustainable transfer hydrogenation for aryl sulfonamides and sulfonyl chlorides is described. The protocol is chemoselective and uses neither catalyst nor solvent.     

Exclusive 1,2-Reduction of Functionalised Conjugated Aldehydes with Sodium Triacetoxyborohydride

Functionalised α, β-unsaturated aldehydes were exclusively reduced to allylic alcohols with sodium-triacetoxyborohydride. Neither saturated alcohol nor saturated aldehydes are obtained. Conjugated ketones are not reduced.     

A new method for the pH calculation of solutions and mixtures of acids,bases and salts

The improved successive approximation method calculates the exact [H⁺] and pH value of solutions and mixtures of acids, bases and salts, and can be applied to titration data. The procedure consists in the calculation of the concentration of all species present in solution, selection of the appropriate rule of electroneutrality and introduction of suitable correction factors in order to obtain a final quadratic equation which is easily solved. Compared with existing methods of pH calculation, which are based on the Newton-Raphson iteration procedure, the proposed method requires a smaller number of iterations and a shorter calculation time. As there are no limitations on the number of compounds, nor on the number or values of acidity and basicity constants, nor on the concentration range, complex problems can be solved and titration curves plotted in a short time.     

Determination of certain phenothiazine drugs with diazotized p-nitroaniline

A colorimetric method for the determination of 7 phenothiazine drugs by interaction with diazotized p-nitroaniline has been developed. Neither the degradation products of the drugs nor the common excipients in pharmaceutical preparations interfere.     

Detection of some nitrogen compounds and the semiquantitative determination of diphenylamine with p-dimethylaminobenzaldehyde by capillary solid-state spot-tests

Capillary solid-state spot-tests for nitrogen compounds by reaction with p-dimethylamino-benzaldehyde are described. The tests are neither specific nor universally applicable for nitrogen compounds.     

Hartree–Fock and density functional theory calculations for the reaction mechanism of nitric oxide reductase cytochrome P450nor from Fusarium oxysporum

A reaction mechanism of a nitric oxide reductase, cytochrome P450nor (P450nor) from Fusarium oxysporum, was clarified by using Density functional theory and Hartree–Fock calculations. In this reaction mechanism, molecular orbital (MO) analysis revealed that the NO ligand dissociates from the heme iron immediately after one-electron reduction by NADH, and MO energy analysis revealed that NADH acts as a one-electron reducer, not as a two-electron reducer, and that NADH has a pivotal role different from other one-electron reducers. The role of NADH is to act as a double one-electron donor (i.e. one-electron transfer occurring twice) and to combine with the NO⁻ molecule by charge recombination reaction. Our quantum chemical calculations indicated that all reactions occurring in the heme pocket are too fast to become rate-limiting. Therefore, the rate-limiting steps in the proposed reaction mechanism are the process of capturing NO and NADH into the heme pocket and the process of expelling a product generated in the heme pocket. Kinetics of these processes was discussed based on large-amplitude vibration, which helps capturing and expelling processes in a widely opened heme pocket of P450nor. The reaction mechanism proposed here well explains published experimental data.