Synthesis of Pyrrolo[2′,3′:4,5]Furo[3,2-c]Pyridine-2-Carboxylic Acids

1H-Pyrrolo[2′,3′:4,5]furo[3,2-c]pyridine-2-carboxylic acid (6a) and its 1-methyl (6b) and 1-benzyl (6c) derivatives were synthesized. 3-(5-Methoxycarbonyl-4H-furo[3,2-b]-pyrrole-2-yl)propenoic acid (1) was converted to the corresponding azide 2, which in turn was cyclized to give 3 by heating in diphenylether. The pyridone 3 obtained was aromatized with phosphorus oxychloride, then reduced with zinc in acetic acid to give methyl 1H-pyrrolo[2′,3′:4,5]furo[3,2-c]pyridine-2-carboxylate (5), which by hydrolysis gave the corresponding carboxylic acid 6a.     

Analysis of [2H7]methionine, [2H4]methionine,methionine, [2H4]homocysteine and homocysteine in plasma by gas chromatography–mass spectrometry to follow the fate of administered [2H7]methionine

Homocysteine plays a key role in several pathophysiological conditions. To assess the methionine–homocysteine kinetics by stable isotope methodology, we developed a simultaneous quantification method of [²H₇]methionine, [²H₄]methionine, methionine, [²H₄]homocysteine and homocysteine in rat plasma by gas chromatography–mass spectrometry (GC–MS). [¹³C]Methionine and [¹³C]homocysteine were used as analytical internal standards to account for losses associated with the extraction, derivatization and chromatography. For labeled and non-labeled homocysteine measurements, disulfide bonds between homocysteine and other thiols or proteins were reduced by dithiothreitol. The reduced homocysteine and methionine species were purified by cation-exchange chromatography and derivatized with isobutyl chlorocarbonate in water–ethanol–pyridine. Quantification was carried out by selected ion monitoring of the molecular-related ions of N(O,S)-isobutyloxycarbonyl ethyl ester derivatives on the chemical ionization mode. The intra- and inter-day precision of the assay was less than 6% for all labeled and non-labeled methionine and homocysteine species. The method is sensitive enough to determine pharmacokinetics of labeled methionine and homocysteine.     

EFFICIENT METHODS FOR THE SYNTHESIS OF [2-15N]GUANOSINE AND 2′-DEOXY[2-15N]GUANOSINE DERIVATIVES

The nucleophilic addition–elimination reaction of 2′,3′,5′-tri-O-acetyl-2-fluoro-O ⁶-[2-(4-nitrophenyl)ethyl]inosine (8) with [¹⁵N]benzylamine in the presence of triethylamine afforded the N ²-benzyl[2-¹⁵N]guanosine derivative (13) in a high yield, which was further converted into the N ²-benzoyl[2-¹⁵N] guanosine derivative by treatment with ruthenium trichloride and tetrabutyl-ammonium periodate. A similar sequence of reactions of 2′,3′,5′-tri-O-acetyl-2-fluoro-O ⁶-[2-(methylthio)ethyl]inosine (9) and the 6-chloro-2-fluoro-9-(β-D-ribofuranosyl)-9H-purine derivative (11), which were respectively prepared from guanosine, with potassium [¹⁵N]phthalimide afforded the N ²-phthaloyl [2-¹⁵N]guanosine derivative (15; 62%) and 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-6-chloro-2-[¹⁵N]phthalimido-9H-purine (17; 64%), respectively. Compounds 15 and 17 were then efficiently converted into 2′,3′,5′-tri-O-acetyl[2-¹⁵N]guanosine. The corresponding 2′-deoxy derivatives (16 and 18) were also synthesized through similar procedures.     

L2[o,r2]上的人口算子

用LZ〔0,:。〕表示通常意义下的Hilbert空间.在空间L“〔0,1。〕中,人口发展算子A“2’定义如下:定义域。‘A,={。‘·,卜‘·,dP(了) dr一“(r)p(,)〔LZ〔o,:,〕;p(o)_。f犷,,_,.,、:,_、*,_、J_1、*‘_、二。,,、‘,*、‘_、__dp(:)=夕l无(r)h(了)户(,)d了卜对p(1)〔D(A),(AP)(7)=一丝书井三 rJ九一’一“一’J‘一‘一’dT一“(r)P(犷),其中,1。为社会中人能活到的最大年龄,〔;,,12〕为妇女育龄区间,h(1)表示生育模式,k(下)表示女性比例函数,那(犷)表示相对死亡率,口>o为妇女总和生育率.拼(r),k(了),h(了)满足下面条件(I).召(,),…     

Urinary cell cycle arrest biomarker [TIMP-2]·[IGFBP7] in patients with hepatorenal syndrome

Abstract

Background: Patients with hepatorenal syndrome carry a high short-term mortality. Early diagnosis and treatment are essential for patients’ outcome. Nevertheless diagnosis of HRS remains difficult. First-line therapy terlipressin is often associated with severe complications. Biomarkers become more on focus for an early diagnosis.

Objective: The aim of this study was to test the diagnostic accuracy of urinary [TIMP-2]·[IGFBP7] for HRS patients and prognostic value for therapy responding patients.

Material and methods: NephroCheck^® measures urinary concentrations of TIMP-2 and IGFBP-7, both indicating stress of renal cells and associated with induction of cell cycle arrest. 22 HRS patients and 30 patients with normal kidney function were included. [TIMP-2]·[IGFBP7] was measured using NephroCheck^®. HRS patients receiving terlipressin were also examined.

Results: [TIMP-2]·[IGFBP7] values did not differ significantly (1.3?±?2.09 vs. 1.03?±?1.03; p?=?0.55). Furthermore, there was no significant difference of [TIMP-2]·[IGFBP7] regarding response of terlipressin (1.32?±?2.39 vs. 0.81?±?1.05; p?=?0.56). Low [TIMP-2]·[IGFBP7] values were significantly associated with higher mortality (p?=?0.01).

Conclusions: The results of this study suggest that [TIMP-2]·[IGFBP7] is not suitable for diagnostic of HRS and prediction of therapy response, but there might be evidence for prognostic value of [TIMP-2]·[IGFBP7] in regard to mortality of liver cirrhosis patients.     

生物工程技术讲座[八]

应用微细胞检测基因产物的方法由于质粒和噬菌体等的DAN分子能在细胞内进行自我复制,以及DNA重组技术的普及,质粒DNA做为异源性DNA分子的载体,在基因工程中目前已被广泛应用。在克隆或分析真核生物或原核生物的多种不同基因时,常用检测基因表达来确定其存在。把含有某一目的基因的DNA片段和载体质粒的DNA进行重组,再通过重组DNA在受体细胞中的转录、翻译、     

Synthesis of novel spiro[pyrazolo[4,3-d]pyrimidinones and spiro[benzo[4,5]thieno[2,3-d]pyrimidine-2,3′-indoline]-2′,4(3H)-diones and their evaluation for anticancer activity

An efficient and novel method for the preparation of spiro[pyrazolo[4,3-d]pyrimidin]-7′(1′H)-ones by the condensation of 4-amino-1-methyl-3-propylpyrazole-5-carboxamide with ketones under mild conditions using catalytic InCl₃ was reported. This method has been extended for the synthesis of novel spiro[benzo[4,5]thieno[2,3-d]pyrimidine-2,3′-indoline]-2′,4(3H)-dione which are having potential applications in medicinal chemistry. All the synthesized compounds were evaluated for their anti-proliferative properties in vitro against cancer cell lines and several compounds were found to be active. Further in vitro studies revealed that inhibition of sirtuins could be the possible mechanism of action of these molecules.     

[B2-Lys]-胰岛素的制备与性质

本文报道了用化学半合成途径从天然猪胰岛素制备[B2-Lys]-胰岛素的过程。人胎盘细胞膜胰岛素受体结合试验表明:[B2-Lys]-胰岛素的受体结合能力只有天然胰岛素的80％,降兔血糖作用与时间关系的结果表明它没有长效作用。本文还对这些结果进行了讨论。     

光合作用中的[H]与呼吸作用中的[H]相同吗？

答：这里的[H]并不是指氢离子（H＋）,而是指辅酶中的氢（还原性氢）,[H]的产生与利用即NADH、FADH。和NADPH的产生与利用。光合作用与呼吸作用中产生和利用的[H]不同,光合作用产生及利用NADPH．而呼吸作用产生与利用的[H]主要是NADH与FADH2。     

An Efficient Method for the Synthesis of [4–15N]Cytidine, 2′-Deoxy[4–15N]Cytidine, [6–15N]adenosine,and 2′-Deoxy [6–15N]adenosine Derivatives

Abstract

Nucleophilic substitution reactions of 4-azolyl-1 β-P-D-ribofuranosylpyrimidin-2(1H)-one and 6-azolyl-9-β-D-ribofuranosyl-9H-purine derivatives, which were converted from uridine and inosine, with [¹⁵N]phthalimide in the presence of triethylamine or DBU gave N ⁴-phthaloyl[4-¹⁵N]cytidine and N ⁶-phthaloyl[6-¹⁵N]- adenosine derivatives, respectively, in high yields. Similar reactions of those azolyl derivatives with succinimide afforded N ⁴-succinylcytidine and N ⁶-succinyladenosine derivatives in high yields. The corresponding 2′-deoxyribonucleosides were also synthesized efficiently through the same procedure.

     

Discovery of novel tricyclic pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4-amine derivatives as VEGFR-2 inhibitors

In an effort to develop ATP-competitive VEGFR-2 selective inhibitors, a novel series of tricyclic pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4-amine derivatives were designed and synthesized. These compounds were characterized by IR, ¹H NMR, ¹³C NMR, elemental and mass spectral analyses. Docking studies have given a partial insight into the molecular determinants of the activity of this novel series in VEGFR-2 kinase active site. Moreover, these compounds were assessed at 10 μM for their selective inhibitory activities over a panel of 6 human kinases, namely VEGFR-1/Flt-1, VEGFR-2/KDR, EGFR, CDK5/p25, GSK3α and GSK3β. Compound N-(4,6-dimethylthieno[2,3-b]pyridine)-7,9-dimethylpyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4-amine (9d) exhibited the most potent and selective inhibitory activity against VEGFR-2/KDR over the six human kinases, with an IC₅₀ value 2.6 μM. The identification of this hit candidate could aid the design of new tricyclic-based VEGFR-2 kinase modulators.     

云南高黎贡山[虫脩]目昆虫五新种及污色无翅刺[虫脩]雄性的发现（[虫脩]：异[虫脩]科，[虫脩]科）

记述云南高黎贡山[虫脩]目异[虫脩]科和[虫脩]科5个新种,即刺胸阿异[虫脩]Aruanoidea notata,sp．nov．,高山短肛[虫脩]Baculum altissimum,sp．nov．,光亮拟短肛[虫脩]Parabaculum laevigatum,sp．nov．,双角刺[虫脩]Cnipsomorpha biangulatus,sp．nov．,黑缘介[虫脩]Interphasma marginatum,sp．nov．,并且首次记述了污色无翅刺蟾Cnipsomorpha colorantis（Chen et He）的雄性。模式标本分别存放于北京林业大学与中国林业科学研究院昆虫标本馆。     

绿藻[FeFe]氢化酶

该文介绍了绿藻[FeFe]氢化酶的研究现状,包括酶的结构、催化中心、金属簇的性质,以及对氧的敏感性和可能的解决办法。并且对已报道的绿藻[FeFe]氢化酶基因及其调控等问题作了介绍。     

Assay of Δ1-piperideine-2-carboxylate and synthesis of l-[14C]pipecolate from dl-[14C]pipecolate

Four assay methods were tested for the measurement of Δ¹-piperideine-2-carboxylate, a proposed alicyclic ketimino acid intermediate in the pathway of lysine metabolism to l-pipecolate, and the product of d-amino acid oxidase on d-pipecolate. The method using Δ¹-piperideine-2-carboxylate reductase from Pseudomonas putida was found to be most sensitive and specific. Measurement of Δ¹-piperideine-2-carboxylate by reduction with NaBH₄ and ninhydrin assay of the resultant pipecolate, by direct acidic ninhydrin assay, and by o-aminobenz-aldehyde assay were less desirable because of lower sensitivity and specificity. Two synthetic methods for preparing l-[¹⁴C]pipecolate from the racemic dl-[¹⁴C]pipecolate were investigated. Incubation of dl-[¹⁴C]pipecolate with a combination of d-amino acid oxidase and Δ¹-piperideine-2-carboxylate reductase or d-amino acid oxidase and NaBH₄ totally inverted the d-isomer to the l-isomer, with $\text{Δ}{}^1\text{-[}{}^{14}\text{C]piperideine-2-carboxylate}$ as an intermediate in each cycle of interconversion. No purification except desalting through a Dowex 50 (H⁺) column was necessary in order to recover l-[¹⁴C]pipecolate in pure form. The yield was 95–97% compared to <50% in the conventional method.     

Discovery of novel 5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine derivatives as γ-secretase modulators (Part 2)

γ-Secretase modulators (GSMs), which lower pathogenic amyloid beta (Aβ) without affecting the production of total Aβ or Notch signal, have emerged as a potential therapeutic agent for Alzheimer’s disease (AD). A novel series of 5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine derivatives was discovered and characterized as GSMs. Optimization of substituents at the 8-position of the core scaffold using ligand-lipophilicity efficiency (LLE) as a drug-likeness guideline led to identification of various types of high-LLE GSMs. Phenoxy compound (R)-17 exhibited especially high LLE as well as potent in vivo Aβ₄₂-lowering effect by single administration. Furthermore, multiple oral administration of (R)-17 significantly reduced soluble and insoluble brain Aβ₄₂, and ameliorated cognitive deficit in novel object recognition test (NORT) using Tg2576 mice as an AD model.     

P[4]、P[6]和P[8]型轮状病毒VP8*核心区蛋白的表达和纯化

为进一步深入研究我国人群中轮状病毒主要流行的P[4]、P[6]和P[8]型毒株的受体结合特点及结构基础,本研究将P[4]、P[6]和P[8]型毒株VP8*核心区(VP8*core)基因分别构建到原核表达载体pGEX4T-1和pET30a中,利用大肠杆菌表达获得轮状病毒P[4]、P[6]和P[8]型毒株VP8*核心区蛋白,并通过亲和层析分别纯化得到VP8*core-GST融合蛋白和VP8*-his标签蛋白,SDS-PAGE显示蛋白大小分别为46kDa和20kDa。综上,本研究成功构建了pGEX4T-1-VP8*core和pET30a-VP8*core重组质粒,利用原核表达系统得到VP8*coreGST融合蛋白和VP8*core-his蛋白,为VP8*蛋白的功能和结构研究提供基础。     

Efficient Synthesis of [2-15N]Guanosine and 2′-Deoxy[2′-15N]Guanosine Derivatives Using N-(tert-Butyldimethylsilyl)[15N]Phthalimide as a 15N-Labeling Reagent

Nucleophilic aromatic substitution of 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-6-chloro-2-fluoro-9 H-purine with N-(tert-butyldimethylsilyl)[ ¹⁵ N]phthalimide in the presence of a catalytic amount of CsF at room temperature in DMF efficiently afforded the 6-chloro-2-[ ¹⁵ N]phthalimidopurine derivative, which was subsequently converted to the [2-¹⁵N]guanosine derivative was also efficiently synthesized through a similar procedure.     

Crystal structure and properties of [TTF]2.5[V(mnt)3 ]·0.5CH2ClCH2Cl[TTF = tetrathiafulvalene and mnt = 1,2-dicyanoethylene-1,2-dithiolate(2−)]

The title salt was obtained by a reaction of [TTF]₃ [BF₄]₂ (TTF = tetrathiafulvalene) with [NMe₄]₂ [V(mnt)₃] [mnt = 1,2-dicyanoethylene-1,2- dithiolate(2−)] in a mixture of 1,2-dichloroethane and acetonitrile (3:2 ν/ν). A single crystal X-ray analysis of it revealed a TTF columnar structure consisting of both TTF⁰ and the TTF^·+ radical cation and the distorted octahedral geometry of the [V(mnt)₃]²⁻ anion. The salt crystallizes in a monoclinic system, space group C2/c with unit cell constants a = 25.428(3), b = 12.434(2), c = 25.477(3) Å, β = 92.428(3)° and Z = 8. The structure was solved by the direct method and refined, on the basis of 3854 [|F_o| > 3σ(F)] observed data, to an R value of 0.078. The salt e`xhibits electrical conductivity of 1.7 x 10⁻⁴ S cm⁻¹ at 25°C for a compacted pellet.