Lewis acid-catalyzed diastereoselective hydroarylation of benzylidene malonic esters

Herein we report that simple Lewis acids catalyze the hydroarylation of benzylidene malonates with phenols. Ultimately, 3,4-disubstituted dihydrocoumarins are obtained via a hydroarylation-lactonization sequence. Moreover, the dihydrocoumarins are formed with a high degree of diastereoselectivity favoring the trans stereoisomer

Mild Decarboxylative Allylation of Coumarins

Allyl esters of 3-carboxylcoumarins undergo facile decarboxylative coupling at just 25–50 °C. This represents the first extension of decarboxylative C–C bond-forming reactions to the coupling of aromatics with sp3-hybridized electrophiles. Finally, the same concept can be applied to the sp2–sp3 couplings of pyrones and flavones. Thus, a variety of biologically important heteroaromatics can be readily functionalized without the need for strong bases or stoichiometric organometallics that are typically required for more standard cross-coupling reactions

AN INTEGRATED FRAMEWORK FOR QUALITY EVALUATION OF FRUITS AND VEGETABLE STORE LOCATED IN THE SUPERMARKET UNDER UTOPIAN ENVIRONMENT

Customer satisfaction depends on the availability of different varieties of fruits and vegetables in a supermarket store as well as the quality of this supermarket store for fruits and vegetables. The store may contain different variety of fruits and vegetables in a utopian environment. Apart from this, there are several quality parameters of a fruits and vegetable store. The quality evaluation of fruits and vegetable stores located in a supermarket is a big challenge for managerial personnel. Here, a quality evaluation framework is proposed for the fruits and vegetable store. The committee of experts identifies and finalizes the quality evaluation parameters through a brainstorming session. Fuzzy AHP is used to calculate the weights of evaluation parameters. A fuzzy TOPSIS generally ranks for the alternative stores. An improved fuzzy TOPSIS, which is named fuzzy k-TOPSIS, is proposed here to evaluate the quality of fruits and vegetable stores located in a supermarket. The fuzzy k-TOPSIS will provide rank as well as classification of the alternatives. A numerical example is demonstrated for a better understanding of the proposed framework

UBE3A and Its Link With Autism

UBE3A is a dual function protein consisting of ubiquitin ligase as well as transcriptional co-activator function. UBE3A gene is imprinted in the brain with preferential maternal-specific expression particularly in the neuron and loss of activity of the maternally inherited UBE3A causes Angelman syndrome (AS), characterized by severe mental retardation, lack of speech, seizures and autistic features. Interestingly, duplication, triplication, or gain-of-function mutations in the UBE3A gene are also linked with autism clinically distinguished by social impairments and stereotyped behaviors. These findings indicate that the expression and activity of UBE3A must be tightly regulated during brain development and UBE3A might be playing a crucial role in controlling synaptic function and plasticity through proteasome-mediated degradation as well as transcriptional regulation of its target proteins. In fact, several recent reports demonstrated the role of UBE3A in the modulation of synaptic function and plasticity. This review focuses on the critical role of UBE3A in regulating the synaptic function and how its altered activity is associated with autism

Mechanistic origin of the stereodivergence in decarboxylative allylation

A stereochemical test has been used to probe the mechanism of decarboxylative allylation. This probe suggests that the mechanism of DcA reactions can change based on the substitution pattern at the α-carbon of the nucleophile, however reaction via stabilized malonate nucleophiles is the lower energy pathway. Lastly, this mechanistic proposal has predictive power and can be used to explain chemoselectivities in decarboxylative reactions that were previously confounding

Effect of microbial load on the condition index of the edible oyster, Saccostrea cucullata in the Sundarbans, India

The effect of microbial load on the condition Index of the edible oyster, Saccostrea cucullata were analysed on monthly basis during 2010 and 2011 from the three different stations (Namkhana, Frasergaunge and Sajnekhali) of Indian Sundarbans. The results showed significant variation with respect to microbial load between stations and seasons, which is reflected in the tissue of edible oyster. Significant positive correlations were observed between microbial load of the ambient environment and the tissue system of oyster. The Condition Index of the oyster species also exhibited negative correlation with the microbial load of oyster tissue, which confirms the negative stress induced by microbes on the growth and survival of the species

Diversity of Birds Fauna in Jhargram, West Bengal, India

Jhargram is a newly formed district, separated from Paschim Medinipur district on 4th April, 2017. The biodiversity of Jhargram is very rich, especially on avifaunal diversity due to its well vegetation, less human interference, low pollution level and good environmental health. The following paper represents the survey report on birds for two years, annotated checklist of bird species with Latin name and IUCN status, graphical representation of species composition on different families, study area and study protocol, devices used and some interesting photographs that collect during field surveys. The exhaustive field study showed 132 species in 109 genera under 58 families within 20 orders from Jhargram town and its outskirts. Some avian species are local migrant, while some are long distant migrant, occasional dweller, and maximum are resident. The rich diversity indicates a good environmental quality, lower pollution rate. This is the first hand study that reveals avifaunal diversity from Jhargram for first time and some rare species of birds from Jhargram are reported on this article

Thermodynamic and kinetic characteristics of an a-amylase from Bacillus licheniformis SKB4

An amylolytic bacterial strain, Bacillus licheniformis SKB4 produced maximum amylase at pH 6.5 at 42 °C, and at late stationary phase (24 h) of growth. Starch and peptone were found the best supporting carbon and nitrogen source with C:N ratio of 1:2 for amylase production. The purified enzyme was non-responsive to most of the metal ions except K+ and Mg++ (1.0 mM). The enzyme was stable and active at pH 6.5. The enzyme showed optimum temperature at 90 °C with 10 min of half life (t½) at 100 °C. The Q10 of the enzyme was 1.0. The thermodynamic principles like activation energy, free energy for substrate binding and transition state of the enzyme were found 31.53, 5.53 and -17.4 KJ/Mol of starch, respectively. The kinetic constant like Vmax, Km, K catand catalytic efficiency (Kcat/Km)for starch were found to be 1.04 μmol mg-1 min-1, 6.2 mg ml-1,2 × 103 S-1 and 3.22 × 102 ml mg-1 S-1,respectively. All these findings suggested that this amylase has unique characteristics for starch hydrolysis in respect to thermostability and kinetic properties