Gold(I)-catalysed synthesis of a furan analogue of thiamine pyrophosphate.

An analogue of thiamine having a furan ring in place of the thiazolium ring has been synthesised by a short and efficient route, involving gold(I)-catalysed cyclisation of an alkynyl alcohol to form the furan ring. The furan analogue of thiamine diphosphate (ThDP) was also made and tested for binding to and inhibition of pyruvate decarboxylase (PDC) from Zymomonas mobilis (overexpressed in E. coli with a N-terminal His-tag). It is a very strong inhibitor, with a K i value of 32.5 pM. It was also shown that the furan analogue of thiamine can be functionalised at the C-2 position, which will allow access to mimics of reaction intermediates of various ThDP-dependent enzymes.This work was supported by a studentship from the Cambridge Commonwealth Trust (A.I.)This is the final version. It was first published by the Beilstein-Institut at http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?publicId=1860-5397-10-27

Structural and spectroscopic analysis of wurtzite (ZnO)1−x(Sb2O3)x composite semiconductor

Abstract The structural, vibrational and impedance analysis for (ZnO) 1− x (Sb 2 O 3 ) x composite synthesized by solid state reaction technique were carried out in the present investigation. X-ray diffraction (XRD) study showed that (ZnO) 1− x (Sb 2 O 3 ) x composite has hexagonal (wurtzite) crystal structure. Variation in lattice constants with Sb-doping indicated the proper incorporation of Sb dopant in ZnO host matrix. The results of Raman spectroscopy test suggested the signature of E 2 (high) and E 1 (TO) Raman modes, and verified the wurtzite structure of (ZnO) 1− x (Sb 2 O 3 ) x composite. Two additional phonon bands (671, 712) cm −1 appeared in Raman spectra of composite samples due to the existence of the lattice defects caused by Sb doping or may be other intrinsic lattice defects formed during the synthesis of (ZnO) 1− x (Sb 2 O 3 ) x composite. The frequency dependent on the electrical characteristics, such as, impedance ( Z ), dielectric constant ( e ) and AC conductivity ( σ ) have been studied in a range of frequencies for different Sb concentration at room temperature. The electrical measurement results showed that the impedance increased with Sb dopant concentration, while dielectric constant and AC conductivity decreased with Sb dopant concentration

A study of English teachers and students’ perception about the differences between annual and semester system of education at postgraduate level in Mardan

AbstractThis research study tried to seek the perception of English teachers and students’ about the differences between Annual and Semester system in terms of students’ learning strategies at postgraduate level. A public sector university in Mardan (established in February 2009) provided the researchers a population who were new to Semester system and who had been seeking education in Annual system before joining it. In order to achieve the objective of the study, a questionnaire was distributed among a randomly selected 120 students having experience of both the educational systems, and interviews with 10 teachers were conducted to record their perception towards both systems of education.The analysis of the data got from both the tools showed that there was found a significant difference between Annual and Semester system in terms of students learning strategies. In Annual system students used to get ample time to master the target subjects, whereas in Semester system, the students had to synthesize the subjects and were not only made to undergo rigorous evaluation in terms of both intellectual and emotional growth

(2E)-3-(4-Chloro­phen­yl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one

In the mol­ecule of the title compound, C13H10ClNO, the benzene and pyrrole rings are oriented at a dihedral angle of 7.37 (12)°. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric R 2 2(10) dimers. There are C—H⋯π inter­actions between benzene and pyrrole rings and a benzene C—H group. A weak π–π inter­action between the pyrrole rings [centroid–centroid distance 3.8515 (11) Å] further stabilizes the structure. There is also a π inter­action between the pyrrole ring and the carbonyl group, with a carbon–centroid distance of 3.4825 (18) Å

Estimation of Genetic Variability, Heritibility and Correlation for Some Morphological Traits in Spring Wheat

This study was conducted to assess correlation among the six wheat genotypes and their nine crosses at cool climatic conditions of Rawalakot, Azad Jammu & Kashmir. High heritability was observed in flag leaf area, peduncle length and spike length, whereas 1000-grain weight, number of spikelets per spike and plant height showed moderate heritability. Peduncle length, grain yield and plant height, flag leaf area and days to 50% heading showed low genetic advance. Positive direct effect was observed by flag leaf area, numbers of tillers per plant, plant height and number of spikelets per spike while days to 50% heading, number of spikelets per spike and 1000-grain weight showed direct negative effects on yield. High genotypic and  phenotypic  variability  was  observed  by  plant  height,  peduncle  length  and  grain  yield  per  plant. Values of phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all the traits under study. Key words: Spring Wheat, Heritability, Genetic Variability, Correlation and Flag leaf

Marker Assisted Selection for Relative Water Content, Excised leaf Water Loss and Cell Membrane Stability in Cotton

Background: Drought stress is a major limitation in agricultural productivity. In cotton, drought tolerance is a multi-genic trait. The quantitative trait loci (QTLs), conferring drought tolerance in cotton, could be exploited for stress breeding using marker assisted selection.Methods: We have screened drought related varieties of Pakistan using DNA markers to identify reported QTLs for drought tolerance. A total of 44 of these varieties were selected. All varieties were sown in the field to record relative water content, excised leaf water loss and cell membrane stability under drought stress condition. QTLs for relative water content, excised leaf water loss and cell membrane stability were checked from all varieties by using DNA markers NAU-2954, NAU-2715, NAU-6672, NAU-8406 and NAU-6790.Results: Genotypic and phenotypic results showed that the QTL for relative water content qtlRWC-1 present on chromosome 23, linked marker NAU-2954, could be a major QTL conferring drought tolerance in cotton. Using Marker Assisted Selection the variety CRIS-134 showed all concerned QTLs for drought tolerance.Conclusion: QTL for relative water content qtlRWC-1 could be a major QTL for drought stress tolerance in cotton. The variety CRIS-134 may be used for breeding drought tolerant cultivar

Synthesis, Characterization and AntibacterialActivity of Azomethine Derivatives Derived from 2-Formylphenoxyacetic Acid

A series of eight new azomethine derivatives were synthesized by reacting 2-formylphenoxyacetic acid with aromatic amines. The chemical structures of these compounds were confirmed by means of 1H-NMR, 13C-NMR, MS and elemental analysis. The compounds were assayed by the disc diffusion method for antibacterial against Staphylococcus aureus and Escherichia coli. Among the compounds tested, 2a, 2b, 2e, 2g and 2h exhibited good antibacterial activity, almost equal to that of Ciprofloxacin used as standard

Synthesis and spectroscopic studies of new Schiff bases

Abstract: Five novel Schiff bases have been prepared from o-formylphenoxyacetic acid and a series of aminothiazoles to form a number of potentially biologically active compounds. The structures of these Schiff bases have been characterized using IR and 1 H-and 13 C-NMR spectroscopy