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111.
An efficient and facile synthesis of 17-chalconyl derivatives of pregnenolone and their evaluation as antimicrobial agents against various microbial strains is reported. The scheme involves the transformation of the starting pregnenolone acetate into pregnenolone, conversion of pregnenolone to the corresponding chalcone derivatives. The compounds 3a–3j showed significant antimicrobial activity against all microbial strains used for testing. 相似文献
112.
Faheem M Raheel U Riaz MN Kanwal N Javed F us Sahar Sadaf Zaidi N Qadri I 《Molecular biology reports》2011,38(6):3731-3740
More than one third of the world’s population living in tropical and subtropical areas of the world is at risk of dengue infections
and as many as 100 million people are yearly infected. This disease has reemerged during the past 20 years in the form of
an epidemic. Dengue is caused by one of four related serotypes of dengue virus and often leads to severe forms of the disease,
resulting commonly from secondary infections. Dengue virus is a mosquito borne virus, belongs to the family Flaviviridae and consists of a single stranded positive sense RNA genome. Like other RNA viruses it escapes defense mechanisms and neutralization
attempts by mutations, which make it more resistant and adaptable to its environment. Antiviral strategies and vaccine development
is thus impaired and hence to date there is no licensed vaccine available for dengue virus. Here we discuss various efforts
made towards the identification of potential vaccine targets for dengue as well as various strategies employed by research
groups/pharmaceutical companies towards the development of a successful dengue vaccine. 相似文献
113.
Ghassen Abid Yordan Muhovski Jean-Marie Jacquemin Dominique Mingeot Khaled Sassi André Toussaint Jean-Pierre Baudoin 《Plant Cell, Tissue and Organ Culture》2011,107(2):341-353
Two genotypes of common bean (Phaseolus vulgaris L.) were studied to determine the structural cause of seed abortion in this species. In the non-abortive control (wild-type,
cultivar BAT93), the histological analysis revealed a classical pattern of seed development and showed coordinated differentiation
of the embryo proper, suspensor, endosperm tissue and seed coat. In contrast, the ethyl methanesulfonate (EMS) mutant (cultivar
BAT93) showed disruption in the normal seed development leading to embryo abortion. Aborted embryos from these degenerate
seeds showed abnormalities in suspensor and cotyledons at the globular, heart, torpedo and cotyledon stages. Exploring the
feasibility of incorporating the available online bioinformatics databases, we identified 22 genes revealing high homology
with genes involved in Arabidopsis
thaliana embryo development and expressed in common bean immature seeds. The expression patterns of these genes were confirmed by
RT–PCR. All genes were highly expressed in seed tissues. To study the expression profiles of isolated genes during Phaseolus embryogenesis, six selected genes were examined by quantitative RT–PCR analysis on the developing embryos of wild-type and
EMS mutant plants. All selected genes were expressed differentially at different stages of embryo development. These results
could help to improve understanding of the mechanism of common bean embryogenesis. 相似文献
114.
115.
Absolute Configuration of Oplopanone Derivatives From Serphidium stenocephalum: ECD Spectra of Acyclic Ketones With Front‐Octant Contributions
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Nusrat Shafiq Muhammad Saleem Naheed Riaz Muhammad Imran Tousif Abdul Jabbar Rasool Bakhsh Tareen Gennaro Pescitelli 《Chirality》2014,26(1):39-43
The electronic circular dichroism (ECD) spectra of two sesquiterpenoids ( 1 and 2 ) related to oplopanone, obtained from a methanolic extract of the plant Serphidium stenocephalum (Artemisia stenocephala), were measured and reproduced by means of time‐dependent density functional theory (TDDFT) calculations, establishing their absolute configuration. The application of ketone octant rule for carbonyl n‐π* ECD band to compounds 1 and 2 , which include an acyclic carbonyl group, was critically assessed. The peculiar oplopanone skeleton makes a straightforward application of the octant rule impossible, because of the uncertainty related to the shape of the so‐called third nodal surface separating front and back octants. The various group contributions to the carbonyl n‐π* ECD band were estimated with TDDFT calculations on selected molecular models obtained by consecutive dissections from 1 . Chirality 26:39–43, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
116.
Abdul Wadood Muhammad Riaz Amir ul Mulk Momin Khan Sobia Ahsan Haleem Sulaiman Shams Sahib Gul Ayaz Ahmed Muhammad Qasim Farman Ali Zaheer Ul-Haq 《Bioinformation》2014,10(5):299-307
Urease is an important enzyme both in agriculture and medicine research. Strategies based on urease inhibition is critically
considered as the first line treatment of infections caused by urease producing bacteria. Since, urease possess agro-chemical and
medicinal importance, thus, it is necessary to search for the novel compounds capable of inhibiting this enzyme. Several
computational methods were employed to design novel and potent urease inhibitors in this work. First docking simulations of
known compounds consists of a set of arylidine barbiturates (termed as reference) were performed on the Bacillus pasteurii (BP)
urease. Subsequently, two fold strategies were used to design new compounds against urease. Stage 1 comprised of the energy
minimization of enzyme-ligand complexes of reference compounds and the accurate prediction of the molecular mechanics
generalized born (MMGB) interaction energies. In the second stage, new urease inhibitors were then designed by the substitution
of different groups consecutively in the aryl ring of the thiobarbiturates and N, N-diethyl thiobarbiturates of the reference ligands..
The enzyme-ligand complexes with lowest interaction energies or energies close to the calculated interaction energies of the
reference molecules, were selected for the consequent chemical manipulation. This was followed by the substitution of different
groups on the 2 and 5 positions of the aryl ring. As a result, several new and potent diethyl thiobarbiturates were predicted as
urease inhibitors. This approach reflects a logical progression for early stage drug discovery that can be exploited to successfully
identify potential drug candidates. 相似文献
117.
Background
The increasing prevalence of obesity in pregnant women is associated with adverse maternal and neonatal outcomes, and increased costs to healthcare, the economy and broader society.Objectives
To assess the efficacy of behavioural interventions for managing gestational weight gain (GWG) in the pre-conceptual and pregnancy period in overweight, obese and morbidly obese women.Search Methods
A search was performed for published studies in the English language, from date? 2000–31 December 2012 in five electronic databases; PubMed, Scopus, Cochrane Library, CINAHL and PsycINFO.Selection criteria
Studies were included if they compared the efficacy or effectiveness of a particular behavioural intervention in pregnant or pre-conceptual women with standard maternity care. Studies that included women with co-morbid conditions such as diabetes mellitus and polycystic ovarian syndrome were excluded to help isolate the effect of the intervention.Results
Fifteen studies involving 3,426 participants were included. One study (n = 692) focused on the pre-conceptual period and the remaining 14 (n = 2,734) in the pregnancy period. Pooled mean difference for GWG indicated a lower GWG in the intervention groups when compared to standard maternity care groups (n = 1771, mean difference (MD) −1.66 kg, 95% CI −3.12 to −0.21 kg). With respect to the types of participants, considerable heterogeneity between studies was shown in the obese subgroup [Tau2 = 15.61; Chi2 = 40.80, df = 3 (P<0.00001); I2 = 93%].Conclusions
Behavioural interventions in pregnancy may be effective in reducing GWG in obese women without comorbid conditions, but not overweight or morbidly obese women. Behavioural interventions had no effect on postpartum weight loss or retention, gestation week of delivery and infant birth weight in overweight, obese and morbidly obese women. 相似文献118.
Alan M. Friedlander David Obura Riaz Aumeeruddy Enric Ballesteros Julie Church Emma Cebrian Enric Sala 《PloS one》2014,9(1)
We report a reef ecosystem where corals may have lost their role as major reef engineering species but fish biomass and assemblage structure is comparable to unfished reefs elsewhere around the world. This scenario is based on an extensive assessment of the coral reefs of Farquhar Atoll, the most southern of the Seychelles Islands. Coral cover and overall benthic community condition at Farquhar was poor, likely due to a combination of limited habitat, localized upwelling, past coral bleaching, and cyclones. Farquhar Atoll harbors a relatively intact reef fish assemblage with very large biomass (3.2 t ha−1) reflecting natural ecological processes that are not influenced by fishing or other local anthropogenic factors. The most striking feature of the reef fish assemblage is the dominance by large groupers, snappers, and jacks with large (>1 m) potato cod (Epinephelus tukula) and marbled grouper (E. polyphekadion), commonly observed at many locations. Napoleon wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum) are listed as endangered and vulnerable, respectively, but were frequently encountered at Farquhar. The high abundance and large sizes of parrotfishes at Farquhar also appears to regulate macroalgal abundance and enhance the dominance of crustose corallines, which are a necessary condition for maintenance of healthy reef communities. Overall fish biomass and biomass of large predators at Farquhar are substantially higher than other areas within the Seychelles, and are some of the highest recorded in the Indian Ocean. Remote islands like Farquhar Atoll with low human populations and limited fishing pressure offer ideal opportunities for understanding whether reefs can be resilient from global threats if local threats are minimized. 相似文献
119.
In this paper, the heat transfer effect on the unsteady boundary layer flow of a Casson fluid past an infinite oscillating vertical plate with Newtonian heating is investigated. The governing equations are transformed to a systems of linear partial differential equations using appropriate non-dimensional variables. The resulting equations are solved analytically by using the Laplace transform method and the expressions for velocity and temperature are obtained. They satisfy all imposed initial and boundary conditions and reduce to some well-known solutions for Newtonian fluids. Numerical results for velocity, temperature, skin friction and Nusselt number are shown in various graphs and discussed for embedded flow parameters. It is found that velocity decreases as Casson parameters increases and thermal boundary layer thickness increases with increasing Newtonian heating parameter. 相似文献
120.