首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
《Cell biology international》2019,43(12):1519-1519
The above article from Cell Biology International, published online on 07 October 2013 in Wiley Online Library ( wileyonlinelibrary.com ) has been retracted by agreement between the authors, the journal Editor‐in‐Chief and John Wiley & Sons Ltd. The retraction has been agreed due to an error in the detection method used.  相似文献   

2.
Two estrogen receptors (ERs), denoted ERα and ERβ, have been identified in humans and various animal species, including the Japanese quail. Estrogens play a key role in sexual differentiation and in activation of sexual behavior in Japanese quail. The distribution of ERα in the brain of male and female adult quail has previously been studied using immunohistochemistry, whereas in situ hybridization has been employed to study the distribution of ERβ mRNA in males only. In this article, we used in situ hybridization to study the distribution of mRNAs for both ERα and ERβ in brain areas controlling sexual behavior of Japanese quail. Our results show that both ERα mRNA and ERβ mRNA are localized in areas important for sexual behavior, such as the preoptic area and associated limbic areas, in both males and females. Moreover, we found differences in distribution of mRNA for the two receptors in these areas. The results of this article support previously reported data and provide novel data on localization of ER mRNAs in adult quail brain of both sexes. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005  相似文献   

3.
Myung Ho Hyun 《Chirality》2015,27(9):576-588
Crown ether‐based chiral stationary phases (CSPs) have been known to be useful for the resolution of racemic primary amino compounds. In particular, CSPs based on (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid have been reported to be useful for the resolution of secondary amino compounds as well as primary amino compounds. In this article, the process of developing various CSPs based on (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid to improve the chiral recognition efficiency and/or the stability of the CSPs and their applications to the resolution of various primary and nonprimary amino compounds are reviewed. Chirality 27:576588, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   

4.
(S)‐(?)‐1‐(1′‐napthyl)‐ethanol (S‐NE) is an important intermediate for the preparation of mevinic acid analogs, which is used for the treatment of hyperlipidemia. The objectives of the study were to isolate a microorganism that could effectively reduce 1‐acetonaphthone (1‐ACN) to S‐NE, to determine the influence that the physicochemical parameters would have on the reduction by the isolated microorganism, and to attempt large‐scale studies with the microorganism. Over the years fungi have been considered a promising biocatalyst and it has been presumed that many fungal species have not been isolated and therefore the current study focused on possible isolation of these microorganisms. A total of 72 fungal isolates were screened for their ability to reduce 1‐ACN to its corresponding alcohol. The isolate, EBK‐62, identified as Alternaria alternata, was found to be the most successful at reducing the ketone to the corresponding alcohol in the submerged culture. The reaction conditions were systematically optimized for the reducing agent A. alternata EBK62, which showed high stereospecificity and good conversion for the reduction. The preparative scale study was carried out in a 2 L bioreactor and a total of 4.9 g of S‐NE in optically pure form (>99% enantiomeric excess) was produced in 48 h. Chirality 28:669–673, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

5.
Organocatalytic enantioselective synthesis of α‐indolyl phosphonates has been successfully carried out via asymmetric Friedel‐Crafts alkylation of substituted indoles with (E)‐dialkyl 3‐oxoprop‐1‐enylphosphonates in 48–82% yield and 73–96% ee. Chirality, 2009. © 2008 Wiley‐Liss, Inc.  相似文献   

6.
The reduction of the axially chiral N‐(o‐aryl)‐5,5‐dimethyl‐2,4‐oxazolidinediones by NaBH4 yielded axially chiral N‐(o‐aryl)‐4‐hydroxy‐5,5‐dimethyl‐2‐oxazolidinone enantiomers having a chiral center at C‐4, with 100% diastereoselectivity as has been shown by their 1H and 13C NMR spectra and by enantioselective HPLC analysis. The resolved enantiomeric isomers were found to interconvert thermally through an aldehyde intermediate formed upon ring cleavage via a latent ring‐chain‐ring tautomerization. It was found that the rate of enantiomerization depended on the size and the electronic effect of the ortho substituent present on the aryl ring bonded to the nitrogen of the heterocycle. Chirality 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

7.
The liquid chromatographic separation of permethrin enantiomers on chiral β‐cyclodextrin‐based stationary phase has been investigated. All four enantiomers are obtained by using simple methanol and water mobile phase, under gradient mode. The method was optimized and validated. The relationship between temperature and chromatographic parameters: k′ (capacity factor), α (separation factor) and Rs (resolution factor) was studied. Van't Hoff's curves for each enantiomer were plotted for temperature range 288–318 K. It was noticed that the response factor ratio of permethrin isomers differ and calculated value is found to be 1.66 (cis/trans, for n = 5). This method has been used for determining permethrin enantiomer ratio for a few samples of working standards and one formulation. Chirality 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

8.
Retraction: Kamath PR, Joseph MM, Ajees AA, et al. Bisindole‐oxadiazole hybrids, T3P mediated synthesis and appraisal of their apoptotic, antimetastatic and computational Bcl‐2 binding potential. J Biochem Mol Toxicol . 2017;31:e21962. https://doi.org/10.1002/jbt.21962 The above article from the Journal of Biochemical and Molecular Toxicology , published online on 19 July 2017 in Wiley Online Library ( https://onlinelibrary.wiley.com/doi/abs/10.1002/jbt.21962 ) and in Volume 31, Issue 11, has been retracted by agreement of the Journal Editor‐in‐Chief, Dr Hari Bhat, and Wiley Periodicals, Inc. The retraction has been agreed due to the absence of access to the original data needed to answer questions about the reliability of some of the findings presented in the paper.  相似文献   

9.
In order to assign the absolute configurations of 8‐tert‐butyl‐2‐hydroxy‐7‐methoxy‐8‐methyl‐9‐oxa‐6‐azaspiro[4.5]dec‐6‐en‐10‐one ( 2a , 2b ), their esters ( 5a , 5b , 5c , 5d ) with (R)‐ or (S)‐2‐methoxyphenylacetic acid ( 4a , 4b ) have been synthesized. The absolute configurations of these compounds have been determined on the basis of NOESY correlations between the protons of the tert‐butyl group and the cyclopentane fragment of the molecules. The crucial part of this analysis was assignment of the absolute configuration at C‐5. Additionally, by calculation of the chemical shift anisotropy, δRS, for the relevant protons, it was also possible to confirm the absolute configurations at the C‐2 centres of compounds 2a , 2b and 5a , 5b , 5c , 5d . Chirality, 25:422–426, 2013.© 2013 Wiley Periodicals, Inc.  相似文献   

10.
A new set of optically active 2,3,3‐ and 2,7,7‐trimethyl‐substituted γ‐aminonorbornan‐2‐ols have been obtained from 2‐methylenenorbornane‐1‐carbonitriles derived from (+)‐camphor and (?)‐fenchone and probed as chiral ligands for the enantioselective addition of diethylzinc to benzaldehyde. This has allowed the study of the structural factors influencing the chirality transfer, such as variation of the relative configuration at C(2) and steric hindrance at C(2), C(3), and C(7) positions of norbornane, which result in the observance of the important role played by the gem‐dimethyl position in γ‐aminonorbornan‐2‐exo‐ols. An empirical rationalization of the obtained experimental results has been realized on the basis of energetically‐favored diastereomeric Noyori‐like transition states. Chirality 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

11.
A simple and straightforward four‐step synthesis of novel diastereomeric L‐phenylalanine‐derived pyrazolidin‐3‐ones is described. The absolute configuration of the novel C(5) stereogenic centre has been unambiguously determined by single crystal X‐ray analysis and via chemical interconversions. A series of novel thiourea derived pyrazolidinones have been prepared and tested as potential organocatalysts. N(1) un‐substituted pyrazolidinones can be used for the construction of a novel type of bicyclic heterocycles and other selective derivatizations. Chirality 25:541–555, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

12.
The above article, published in the Journal of Cellular and Molecular Medicine on 14 September 2016 in Wiley Online Library (wileyonlinelibrary.com), and in Volume 19, pp. 2136‐2142, has been retracted by agreement between the authors, the journal Editor in Chief, Stefan Constantinescu, and John Wiley & Sons Ltd. The retraction has been agreed due to unattributed overlap of the language used in the “Materials and method” and “Discussion” sections of this study and the following article published in Lung Cancer: “CYP2E1 Rsa I/Pst I polymorphism is associated with lung cancer risk among Asians” by Ping Zhan, Jing Wang, Yu Zhang, Li‐Xin Qiu, Su‐feng Zhao, Qian Qian, Shu‐Zhen Wei, Li‐Ke Yu and Yong Song, Volume 69, 2010, pages 19‐25. REFERENCE Shen Z‐T, Wu X‐H, Li B, Shen J‐S, Wang Z, Li J, Zhu X‐X. CYP2E1 Rsa Ι/Pst Ι polymorphism and lung cancer susceptibility: a meta‐analysis involving 10,947 subjects. J Cell Mol Med. 2015;19:2136‐2142. https://doi.org/10.1111/jcmm.12579  相似文献   

13.
A library of 175 dipeptidomimetics and tripeptidomimetics containing an α‐amino boronic acid or boronate has been synthesized, and the activity toward Mycobacterium tuberculosis, Candida albicans, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa has been screened. Although there is no clear structure–activity relationship, several compounds exhibit promising activity against different pathogens. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.  相似文献   

14.
A sensitive and selective spectrofluorimetric method has been developed for the rapid determination of aluminium. This method is based on the complex formation between aluminium and 2‐hydroxy‐1‐naphthylidene‐(8‐aminoquinoline) (HNAQ). The optimum conditions for the complex formation were a metal‐to‐ligand (M : L) stoichiometric ratio of 1:1, a pH of 5.5 and a 0.20 m acetate buffer. The fluorescence of the complex was monitored at an emission wavelength of 502 nm with excitation at 438 nm. Under these conditions, linear calibration curves were obtained in the ranges 0.05–1 and 1–5 ppm. The detection limit was 3.4 ppb for the former and 13.5 ppb for the latter. The maximum relative standard deviation of the method for an aluminium standard of 200 ppb was 1.5% (n = 5). This method was successfully applied for the determination of aluminium in drinking water, pharmaceutical antacid tablets and suspension samples. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

15.
Epilepsy, one of the most frequent neurological disorders, is still insufficiently treated in about 30% of patients. As a consequence, identification of novel anticonvulsant agents is an important issue in medicinal chemistry. In the present article we report synthesis, physicochemical, and pharmacological evaluation of N‐trans‐cinnamoyl derivatives of R and S‐2‐aminopropan‐1‐ol, as well as R and S‐2‐aminobutan‐1‐ol. The structures were confirmed by spectroscopy and for derivatives of 2‐aminopropan‐1‐ols the configuration was evaluated by means of crystallography. The investigated compounds were tested in rodent models of seizures: maximal electroshock (MES) and subcutaneous pentetrazol test (scPTZ), and also in a rodent model of epileptogenesis: pilocarpine‐induced status prevention. Additionally, derivatives of 2‐aminopropan‐1‐ols were tested in benzodiazepine‐resistant electrographic status epilepticus rat model as well as in vitro for inhibition of isoenzymes of cytochrome P450. All of the tested compounds showed promising anticonvulsant activity in MES. For R(–)‐(2E)‐N‐(1‐hydroxypropan‐2‐yl)‐3‐phenylprop‐2‐enamide pharmacological parameters were found as follows: ED50 = 76.7 (68.2–81.3) mg/kg (MES, mice i.p., time = 0.5 h), ED50 = 127.2 (102.1–157.9) mg/kg (scPTZ, mice i.p., time = 0.25 h), TD50 = 208.3 (151.4–230.6) mg/kg (rotarod, mice i.p., time = 0.25 h). Evaluation in pilocarpine status prevention proved that all of the reported compounds reduced spontaneous seizure activity and act as antiepileptogenic agents. Both enantiomers of 2‐aminopropan‐1‐ols did not influence cytochrome P450 isoenzymes activity in vitro and are likely not to interact with CYP substrates in vivo. Chirality 28:482–488, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

16.
A series of new chiral molecular tweezers, di‐(R,R)‐1‐[10‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐9‐anthryl]‐2,2,2‐trifluoroethyl phthalate (2), isophthalate (3) and terephthalate (4), were synthesized and their structure studied by NMR and molecular mechanics. Their effectiveness as chiral solvating agents for the determination of the enantiomeric purity of chiral compounds using NMR was demonstrated. Chirality 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

17.
The preparation of all four stereoisomers of the proline analog that bears a phenyl group attached to the β carbon either cis or trans to the carboxylic acid (cis‐ and trans‐β‐phenylproline, respectively) has been addressed. The methodology developed allows access to multigram quantities of the target amino acids in enantiomerically pure form and suitably protected for use in peptide synthesis. Racemic precursors of cis‐β‐phenylproline and trans‐β‐phenylproline were prepared from easily available starting materials and subjected to high‐performance liquid chromatography enantioseparation. Semipreparative columns (250 × 20 mm) containing chiral stationary phases based on amylose (Chiralpak IA) (Daicel‐Chiral Technologies Europe, Illkirch, France) or cellulose (Chiralpak IC) were used respectively for the resolution of the cis‐ and trans‐β‐phenylproline precursors. Chirality, 24:1082‐1091, 2012. © 2012 Wiley Periodicals, Inc.  相似文献   

18.
Temporal and spatial regulation of genes mediated by tissue‐specific promoters and conditional gene expression systems provide a powerful tool to study gene function in health, disease, and during development. Although transgenic mice expressing the Cre recombinase in the gastric epithelium have been reported, there is a lack of models that allow inducible and reversible gene modification in the stomach. Here, we exploited the gastrointestinal epithelium‐specific expression pattern of the three trefoil factor (Tff) genes and bacterial artificial chromosome transgenesis to generate a novel mouse strain that expresses the CreERT2 recombinase and the reverse tetracycline transactivator (rtTA). The Tg(Tff1‐CreERT2;Tff2‐rtTA;Tff3‐Luc) strain confers tamoxifen‐inducible irreversible somatic recombination and allows simultaneous doxycycline‐dependent reversible gene activation in the gastric epithelium of developing and adult mice. This strain also confers luciferase activity to the intestinal epithelium to enable in vivo bioluminescence imaging. Using fluorescent reporters as conditional alleles, we show Tff1‐CreERT2 and Tff2‐rtTA transgene activity in a partially overlapping subset of long‐term regenerating gastric stem/progenitor cells. Therefore, the Tg(Tff1‐CreERT2;Tff2‐rtTA;Tff3‐Luc) strain can confer intermittent transgene expression to gastric epithelial cells that have undergone previous gene modification, and may be suitable to genetically model therapeutic intervention during development, tumorigenesis, and other genetically tractable diseases. Birth Defects Research (Part A) 106:626–635, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号