Synthesis of beta-amino acids: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) for activation of Fmoc-/Boc-/Z-alpha-amino acids

A new and efficient method for the homologation of urethane protected alpha-amino acids to its beta-homomers by the Arndt-Eistert method using TBTU as a coupling agent is described. Several Fmoc-/Boc-/Z-protected alpha-amino diazoketone derivatives have been obtained as crystalline solids in good yield. The method is found to be rapid and stereospecific

Low temperature plasma-catalytic NOx synthesis in a packed DBD reactor: effect of support materials and supported active metal oxides

The direct synthesis of NOx from N2 and O2 by non-thermal plasma at an atmospheric pressure and low temperature is presented, which is considered to be an attractive option for replacement of the Haber-Bosch process. In this study, the direct synthesis of NOx was studied by packing different catalyst support materials in a dielectric barrier discharge (DBD) reactor. The support materials and their particle sizes both had a significant effect on the concentration of NOx. This is attributed to different surface areas, relative dielectric constants and particles shapes. The nitrogen could be fixed at substantially lowered temperatures by employing non-thermal plasma-catalytic DBD reactor, which can be used as an alternative technology for low temperature synthesis. The γ-Al2O3 with smallest particles size of 250–160 μm, gave the highest concentration of NOx and the lowest specific energy consumption of all the tested materials and particle sizes. The NOx concentration of 5700 ppm was reached at the highest residence time of 0.4 s and an N2/O2 feed ratio of 1 was found to be the most optimum for NOx production. In order to intensify the NOx production in plasma, a series of metal oxide catalysts supported on γ-Al2O3 were tested in a packed DBD reactor. A 5% WO3/γ-Al2O3 catalyst increased the NOx concentration further by about 10% compared to γ-Al2O3, while oxidation catalysts such as Co3O4 and PbO provided a minor (∼5%) improvement. These data suggest that oxygen activation plays a minor role in plasma catalytic nitrogen fixation under the studied conditions with the main role ascribed to the generation of microdischarges on sharp edges of large-surface area plasma catalysts. However, when the loading of active metal oxides was increased to 10%, NO selectivity decreased, suggesting possibility of thermal oxidation of NO to NO2 through reaction with surface oxygen species

Homologation of alpha-amino acids to beta-amino acids using Boc(2)O

The use of Boc(2)O as a coupling agent in the homologation of N-urethane protected-alpha-amino acid to its beta-homomers by the Arndt-Eistert method is described. The homologation gives good yields without racemization. The use of Boc(2)O as a coupling agent not only allows the easy scale up of the process but also it is cost effective

Microwave assisted Wolff rearrangement: A facile method for the synthesis of Fmoc-β-amino acids

The Wolff rearrangement of α-diazoketones, derived from Fmoc-α-amino acids, under no base conditions on exposure to microwave irradiation for 40 to 60 sec to Fmoc-β-amino acids with retention of configuration in good yield (91-95%) is described

Efficiency of Paddy Farms in India: an Empirical Evidence of TBP Area of Karnataka state

The study on efficiency of paddy farms revealed that majority of the farmers were operating in medium efficiency level (70%) followed by low efficiency level (17%) and high efficiency level(13%) with respect to nitrogen. Similar trend was noticed in plant protection chemicals wherein farmers operating in medium efficiency level (74%) were higher than those of high (13%) and low efficiency levels (13%). The percentage excess of nitrogen usage over the frontier level ranged from 38.86% to 91.03% and plant protection chemicals from 42.53% to 70.54% with increase in nitrogen levels indicating inputs like nitrogen and plant protection chemicals were used indiscriminately in the study area in view of practice of their own method of cultivation. It is suggested that farmers should be trained about adoption of Integrated Nutrient Management (INM) and Integrated Pest Management (IPM) practices in paddy cultivation in TBP area. Key words: Integrated Nutrient Management, IPM, Paddy, Frontier, MVP, OC, Efficienc

Agronomic performance of chickpea affected by drought stress at different growth stages

Susceptibility to drought stress has restrained chickpea productivity at a global level, and the development of drought-tolerant varieties is essential to maintain its productivity. Therefore, the present study was conducted to evaluate genetic divergence in selected genotypes of chickpea and their morpho-physiological responses under irrigated and stressed conditions to identify the traits that account for the better performance of these genotypes under stressed conditions, as well as genotypes with improved drought tolerance. The genotypes were evaluated for two years under irrigated and drought stressed conditions, and significant variation was found amongst the genotypes for different morpho-physiological and yield traits. The maximum reduction was observed for plant yield (33.23%) under stressed conditions. Principle component analysis (PCA)-based biplots and correlation studies established its strong positive correlation with relative water content (RWC), membrane stability index (MSI), chlorophyll index (CI), secondary branches (SB) and yield traits and negative correlations with drought susceptibility index (DSI), days to maturity (DM) and 100 seed weight (100 SW) under drought stress, suggesting their use in selecting drought-tolerant germplasm. Ten genotypes with high values of RWC, MSI, CI, SB, yield traits and lower DSI were identified as drought-tolerant and might serve as ideal donors in the forthcoming breeding of elite chickpea cultivars. The seed-filling stage began earlier in these genotypes, with significantly reduced days to maturity under stressed conditions. Our results indicate selection for earliness offers a promising strategy for the development of drought-tolerant chickpea cultivars

Effect of Sm Doping on Structural and Dielectric Properties of CoFe2O4 Ferrite

Samarium doped cobalt ferrite, CoSmxFe2 – xO4 in which x varies as 0.0, 0.1, 0.3 and 0.5 were synthesized by conventional solid state reaction method. The impact of samarium doping on structural and dielectric properties is studied. The phase formation is confirmed by using XRD technique. The reflection peak broadening increases with increase in Sm concentration. The grain size is calculated by using scanning electron microscope image. The variation in dielectric constant (ɛʼ) and dielectric loss (tanδ) as a function of frequency in the range 20 Hz to 1 MHz is studied. The dielectric constant is enhanced with increase in Sm concentration and decreases with increase in frequency

Characterization of ASR gene and its role in drought tolerance in chickpea (Cicer arietinum L.)

Chickpea has a profound nutritional and economic value in vegetarian society. Continuous decline in chickpea productivity is attributed to insufficient genetic variability and different environmental stresses. Chickpea like several other legumes is highly susceptible to terminal drought stress. Multiple genes control drought tolerance and ASR gene plays a key role in regulating different plant stresses. The present study describes the molecular characterization and functional role of Abscissic acid and stress ripening (ASR) gene from chickpea (Cicer arietinum) and the gene sequence identified was submitted to NCBI Genbank (MK937569). Molecular analysis using MUSCLE software proved that the ASR nucleotide sequences in different legumes show variations at various positions though ASR genes are conserved in chickpea with only few variations. Sequence similarity of ASR gene to chickpea putative ABA/WDS induced protein mRNA clearly indicated its potential involvement in drought tolerance. Physiological screening and qRT-PCR results demonstrated increased ASR gene expression under drought stress possibly enabled genotypes to perform better under stress. Conserved domain search, protein structure analysis, prediction and validation, network analysis using Phyre2, Swiss-PDB viewer, ProSA and STRING analysis established the role of hypothetical ASR protein NP_001351739.1 in mediating drought responses. NP_001351739.1 might have enhanced the ASR gene activity as a transcription factor regulating drought stress tolerance in chickpea. This study could be useful in identification of new ASR genes that play a major role in drought tolerance and also develop functional markers for chickpea improvement