A new proposed model of aldose reductase enzyme inhibition on the basis of an artificial intelligence approach: A computer automated structure evaluation (case) study

A large number of inhibitors of aldose reductase enzyme were submitted to the CASE (computer automated structure evaluation) program in order to ascertain the topological features relevant to activity. On the basis of the twenty-six biophores (activating fragments) and one biophobe (inactivating fragment), a new proposed interaction model was suggested for an aldose reductase enzyme with the chemical inhibitors. The critical relationship between enzyme inhibition and the structure of inhibitors is believed to depend on the relative positions of subordinate regions within the inhibitor structure.     

Platinum-Group Element Distribution in Some Ore Deposits: Results of EPMA and Micro-PIXE Analyses

The distribution of platinum-group elements (PGE) in the Main Sulfide Zone of the Great Dyke of Zimbabwe, in the arsenide ores of Vammala and Kylmäkoski mines in Finland, and in the chromite-Ni arsenide ores from the Ronda and Beni Bousera massifs (Spain and Morocco) has been studied by means of different optical and microanalytical techniques. The results show a bimodal distribution of PGE in the ores from the Great Dyke and the Vammala and Kylmäkoski mines where Pd, Pt and, to lesser extent, Rh occur both as discrete platinum-group minerals and in solid solution in sulfides, arsenides and sulfarsenides. In the ores from Ronda and Beni Bousera, platinum-group elements occur only in solid solution in arsenides and sulfarsenides.Trace electron probe (EPMA) and micro-PIXE analyses of Pd in sulfides, arsenides and sulfarsenides produce comparable results at concentration levels well above their limit of detection (LOD). These are 27–29ppm by EMPA and 2.5–7ppm by micro-PIXE. Whereas trace EPMA on arsenides and sulfarsenides measure Pt concentrations above 33–35ppm, the proximity of the Pt L lines and the As K line severely degrade de detection limit for Pt in micro-PIXE analyses, increasing the LOD up to 440ppm. The rest of PGE were randomly detected by both methods at concentrations close to their LOD.     

Cation sensors based on terpyridine-functionalized boradiazaindacene

A new class of highly luminescent dyes is reported. The characteristic feature of these compounds is that a terpyridine fragment is closely appended to a boradiazaindacene moiety in such a way that cation binding to the vacant terpyridine causes strong perturbations of the photophysical properties of the boradiazaindacene unit. In particular, these sensors are especially applicable to the fluorescence detection of trace quantities of zinc(II) ions in solution. The mechanism of the cation-induced quenching process has been investigated by a combination of electrochemistry, UV/Vis absorption, emission, and NMR spectroscopy. Highly luminescent arrays can be formed by doping transparent polymers with low concentrations of these new dyes. In such materials, the change in photophysical properties upon cation binding is so marked that "cation writing" becomes feasible under routine conditions.     

血清游离羟脯氨酸的快速检测

采用6300黄金系统氨基酸分析仪，在锂柱140min程序生理体液分析方法基础上，建立了血清游离羟脯氨酸（HYP）快速测定方法，并用该法检测了正常人及肾病（有或无肾小铧与肾间质纤维化）病人血清中游离HYP的含量；用该法完成分析的时间为24min，比原方法缩短了116min；该法重复性良好，日内RSD2．3％，日间RSD3．7％，回收率97％；纤维化组血清羟脯氨酸浓度显著高于无纤维化组（P＜0．001）和健康对照组（P＜0．001），用该指标显著增高判断肾纤维化，敏感性100％，特异性915，假阳性9％；该法是一种快速、准确、可靠的血清因浆羟脯氨酸定量检测方法，有利于大批量样品的快速测定，并可为临床判断肾病病人肾纤维化提供辅助诊断指标。     

GAMMA AND PULSE RADIOLYSIS STUDIES OF THE REACTION BETWEEN SUPEROXIDE IONS AND OXYHEMOGLOBIN-METHEMOGLOBIN SYSTEM

Abstract— The radiolytic studies of oxyhemoglobin or methemoglobin in neutral aerated aqueous solutions with formate ions, lead to three conclusions:
The oxidation of oxyhemoglobin by O^-₂ is not important. The observed low oxidation yield is probably due to the slow reaction with hydrogen peroxide produced by O^-₂ disproportionation.
The reduction of methemoglobin in γ radiolysis reaches a plateau which could be explained by structural considerations.
The reduction of methemoglobin by O^-₂ ions, if it occurs, is relatively slow: k = 1.4 × 10³ M ^-1 s^-1. But a problem remains concerning the spectral characteristics of the product.     

Synthesis of functionalized pyrrole and indole derivatives through carbometallation of lithiated double bonds

Bis(2-lithioallyl)amines derived from bis(2-bromoallyl)amines undergo intramolecular carbometallation of a lithiated double bond, giving dilithiated dihydropyrroles. The cyclizations are promoted by N,N,N',N'-tetramethylethylenediamine (TMEDA). Reaction of these intermediates with electrophiles allows the preparation of some new fused and nonfused five-membered functionalized heterocycles. Although 2-lithioallylamines do not suffer intermolecular carbometallation, dimerization products are obtained with their copper or zirconium derivatives. Finally, the application of this new reaction to 2-lithio-N-(2-lithioallyl)anilines leads to 3-lithiomethylindole derivatives, which are transformed to functionalized indole derivatives by reaction with electrophiles.     

手性Ru复合物催化剂的固载化及其不对称氢转移反应催化应用

Chiral Ru-BsDPEN, (1R,2R)-N-p-benzenesulfonyl-1,2-diphenylethylenediamine, catalyst has been immobilized on a mesoporous molecular sieve of MCM-41 type successfully. A hybrid mesoporous molecular sieve was synthesized using a precursor bearing benzene group, which in organosilica were sulfonylated and reacted with (1R,2R)-l,2-diphenylethylenediamine and [RuC1E(p-cymene)]2 successively to afford immobilized catalyst. The Brunauer-Emmett-Teller (BET) surface area and Barrett-Joyner-Halenda (BJH) pore size decreased after immobilization of catalyst onto the mesoporous material. Enantioselective transfer hydrogenation of ketones catalyzed by immobilized catalyst showed the highest yield of 22.36% and e.e. value of 31.47% by using acetophenone as substrate when reaction time was 48 and 16 h respectively.     

New flavonol tetraglycosides from Astragalus caprinus

A new flavonol tetraglycoside, together with four acylated derivatives, were isolated from the leaves of Astragalus caprinus. Their structures were elucidated by spectroscopic methods, mainly 2D NMR, as kaempferol-3-O-[[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][alpha-L-rhamnopyranosyl(1-->2)]]-beta-D-galactopyranoside (1), its 3(Gal)-p-coumaric (2) and 3(Gal)-ferulic (3) esters, and its 4(Gal)-p-coumaric (4) and 4(Gal)-ferulic (5) esters.     

A new and efficient synthesis of 4-functionalized benzo[b]furans from 2,3-dihalophenols

Tandem Sonogashira coupling/5-endo-dig cyclization reactions on 2,3-dihalophenols suppose a straightforward entry to 4-halobenzo[b]furans, which can be easily transformed into 4-functionalized benzo[b]furans, that are difficult to synthesize by other procedures. On the other hand, the starting 2,3-dihalophenols are efficiently prepared from commercially available 3-halophenols, via their N,N-diethyl carbamates by selective lithiation at the 2-positions by treatment with s-BuLi/TMEDA or LDA at low temperature and reaction with halogen electrophilic reagents.