From oligomers to molecular giants of soybean oil in supercritical carbon dioxide medium: 1. Preparation of polymers with lower molecular weight from soybean oil

Polymers with a low molecular weight derived from soybean oil have been prepared in a supercritical carbon dioxide medium by cationic polymerization. Boron trifluoride diethyl etherate was used as an initiator. Influences of polymerization temperature, amount of initiator, and carbon dioxide pressure on the molecular weight were investigated. It is shown that the higher polymerization temperature favors polymers with relatively higher molecular weights. Larger amounts of initiator also provide polymers with higher molecular weights. Higher pressure favors polymers with relatively higher molecular weights. The applications of these soy-based materials will be in the lubrication and hydraulic fluid areas.     

Design,synthesis, biological evaluation and molecular modelling studies of novel quinoline derivatives against Mycobacterium tuberculosis

We herein describe the synthesis and antimycobacterial activity of a series of 27 different derivatives of 3-benzyl-6-bromo-2-methoxy-quinolines and amides of 2-[(6-bromo-2-methoxy-quinolin-3-yl)-phenyl-methyl]-malonic acid monomethyl ester. The antimycobacterial activity of these compounds was evaluated in vitro against Mycobacterium tuberculosis H37Rv for nine consecutive days upon a fixed concentration (6.25 μg/mL) at day one in Bactec assay and compared to untreated TB cell culture as well as one with isoniazide treated counterpart, under identical experimental conditions. The compounds 3, 8, 17 and 18 have shown 92–100% growth inhibition of mycobacterial activity, with minimum inhibitory concentration (MIC) of 6.25 μg/mL. Based on our molecular modelling and docking studies on well-known diarylquinoline antitubercular drug R207910, the presence of phenyl, naphthyl and halogen moieties seem critical. Comparison of docking studies on different stereoisomers of R207910 as well as compounds from our data set, suggests importance of electrostatic interactions. Further structural analysis of docking studies on our compounds suggests attractive starting point to find new lead compounds with potential improvements.     

Genetic Heterogeneity Reveals On-Going Speciation and Cryptic Taxonomic Diversity of Stream-Dwelling Gudgeons (Teleostei,Cyprinidae) in the Middle Danubian Hydrosystem (Hungary)

Although stream-dwelling gudgeons (Cyprinidae, genus: Gobio) are widespread in Central Europe, the taxonomy of this group and the distribution of its species are still unexplored in detail. The aims of our study are to ascertain taxonomic composition and distribution of the former Gobio gobio superspecies in the inner area of the Carpathian Basin. Since the presence of cryptic species is suspected in this area, we examined the taxonomic and phylogenetic relationships of Central European Gobio taxa by sequencing the mitochondrial DNA control region (mtCR). Additionally, we characterized the genetic structure of 27 stream-dwelling gudgeon populations of this area by Amplified Fragment Length Polymorphism (AFLP). Results of mtCR analysis proved the presence of three species already known as G. obtusirostris (dominant in NW-Hungary), G. gobio (sporadic) and G. carpathicus (sporadic). Additionally, the analysis revealed the existence of one doubtful taxon, G. sp1 (dominant in NE-Hungary), and a new isolated haplogroup (dominant in SW-Hungary). Although Network analysis showed significant detachment among haplogroups, their genetic distances were quite small. Therefore Bayesian phylogenetic analysis showed weak nodal support for the branching pattern both for newly described haplotypes, and for the already accepted species. AFLP data showed distinct population structure and a clear pattern of isolation was revealed by distance of stocks. At the same time, level of separation was not affected by the altitudinal position of sites. Moreover we found three major clusters of populations which were separated according to hydrographic regions, and corresponded to the findings of mtCR analysis. Our results suggest the on-going speciation of gudgeons in the Carpathian Basin, however the separation of haplogroups seems to only be an intermediate phase. The discovered natural pattern seems to be only slightly influenced by anthropogenic impacts. Additionally our results put into question the suitability of the recently accepted within Gobio genus taxonomy.     

Genetic diversity among chicken breeds estimated through randomly amplified polymorphic DNA.

The randomly amplified polymorphic DNA (RAPD) markers were used to detect polymorphism among five breeds of chicken i.e. White Leghorn and Rhodes Island Red (selected for part period egg production and egg mass respectively), Red Cornish and White Plymouth Rock (selected for early body weights) and Kadaknath (native breed). Twelve of the fifty random primers screened yielded distinct polymorphic RAPD profiles. Of the total 96 fragments amplified, about 25% showed polymorphism. Using the RAPD data matrix, the within population and between population genetic similarity was estimated. The selected improved breeds showed higher within population genetic similarity in comparison to the native breed. The two meat type breeds showed a high level of genetic similarity between themselves. The White Leghorn breed showed a low genetic similarity with other breeds. The native breed showed highest similarity with Rhodes Island Red. The dendogram was constructed to show phylogenetic relationship among these breeds. As expected, the genetic distances were lowest within similar type breeds and were highest between dissimilar type breeds. The results indicated the effectiveness of RAPD in detecting polymorphism between chicken populations and their applicability in population studies and establishing genetic relationships among the chicken populations.     

Drought Induces Oxidative Stress and Enhances the Activities of Antioxidant Enzymes in Growing Rice Seedlings

When rice seedlings grown for 10 and 20 days were subjected to in vitro drought stress of −0.5 and −2.0 MPa for 24 h, an increase in the concentration of superoxide anion (O₂^.−), increased level of lipid peroxidation and a decrease in the concentration of total soluble protein and thiols was observed in stressed seedlings compared to controls. The concentration of H₂O₂ as well as ascorbic acid declined with imposition of drought stress, however glutathione (GSH) concentration declined only under severe drought stress. The activities of total superoxide dismutases (SODs) as well as ascorbate peroxidase (APX) showed consistent increases with increasing levels of drought stress, however catalase activity declined. Mild drought stressed plants had higher guaiacol peroxidase (GPX) and chloroplastic ascorbate peroxidase (c-APX) activity than control grown plants but the activity declined at the higher level of drought stress. The activities of enzymes involved in regeneration of ascorbate i.e. monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were higher in drought stressed plants compared to controls. Results suggest that drought stress induces oxidative stress in rice plants and that besides SOD, the enzymes of ascorbate-glutathione cycle, which have not been studied in detail earlier under stressful conditions, appear to function as important component of antioxidative defense system under drought stress.     

Genetic characterization of Chikungunya virus from New Delhi reveal emergence of a new molecular signature in Indian isolates

ABSTRACT: BACKGROUND: Chikungunya (CHIK) is currently endemic in South and Central India and exist as co-infections with dengue in Northern India. In 2010, New Delhi witnessed an outbreak of CHIK in the months October-December. This was the first incidence of a dominant CHIK outbreak in Delhi and prompted us to characterize the Delhi virus strains. We have also investigated the evolution of CHIK spread in India. FINDINGS: Clinical samples were subjected to RT-PCR to detect CHIK viral RNA. The PCR amplified products were sequenced and the resulting sequences were genetically analyzed. Phylogenetic analysis based on partial sequences of the structural proteins E1 and E2 revealed that the viruses in the latest outbreak exhibited ECSA lineage. Two novel mutations, E1 K211E and E2 V264A were observed in all Delhi isolates. In addition, CHIKV sequences from eight states in India were analyzed along with Delhi sequences to map the genetic diversity of CHIKV within the country. Estimates of average evolutionary divergence within states showed varying divergence among the sequences both within the states and between the states. We identified distinct molecular signatures of the different genotypes of CHIKV revealing emergence of a new signature in the New Delhi clade. Statistical analyses and construction of evolutionary path of the virus within the country revealed gradual spread of one specific strain all over the country. CONCLUSION: This study has identified unique mutations in the E1 and E2 genes and has revealed the presence of ancestral CHIKV population with maximum diversity circulating in Maharashtra. The study has further revealed the trend of CHIK spread in India since its first report in 1963 and its subsequent reappearance in 2005.     

Discovery of conformationally rigid 3-azabicyclo[3.1.0]hexane-derived dipeptidyl peptidase-IV inhibitors

The induction of conformationally restricted N-(aryl or heteroaryl)-3-azabicyclo[3.1.0]hexane derivatives at P₂ region of compounds of 2-cyanopyrrolidine class was explored to develop novel DPP-IV inhibitors. The synthesis, structure–activity relationship, and selectivity against related proteases are delineated.     

Autoinhibitory Interdomain Interactions and Subfamily-specific Extensions Redefine the Catalytic Core of the Human DEAD-box Protein DDX3

DEAD-box proteins utilize ATP to bind and remodel RNA and RNA-protein complexes. All DEAD-box proteins share a conserved core that consists of two RecA-like domains. The core is flanked by subfamily-specific extensions of idiosyncratic function. The Ded1/DDX3 subfamily of DEAD-box proteins is of particular interest as members function during protein translation, are essential for viability, and are frequently altered in human malignancies. Here, we define the function of the subfamily-specific extensions of the human DEAD-box protein DDX3. We describe the crystal structure of the subfamily-specific core of wild-type DDX3 at 2.2 Å resolution, alone and in the presence of AMP or nonhydrolyzable ATP. These structures illustrate a unique interdomain interaction between the two ATPase domains in which the C-terminal domain clashes with the RNA-binding surface. Destabilizing this interaction accelerates RNA duplex unwinding, suggesting that it is present in solution and inhibitory for catalysis. We use this core fragment of DDX3 to test the function of two recurrent medulloblastoma variants of DDX3 and find that both inactivate the protein in vitro and in vivo. Taken together, these results redefine the structural and functional core of the DDX3 subfamily of DEAD-box proteins.