Production Optimization and Characterization of Recombinant Cutinases from Thermobifida fusca sp. NRRL B-8184

Two genes, cut1 and cut2, of Thermobifida fusca NRRL B-8184 with cutin-hydrolyzing activity were cloned and expressed in Escherichia coli BL21 (DE3) separately. Enhanced expression was achieved after screening of six different media, optimization of the culture conditions and medium components. Among the screened media, modified Terrific Broth was found to be the best for maximum production of recombinant cutinases in E. coli BL21 (DE3). Under optimal conditions, the production of recombinant Cut1 and Cut2 (cutinases) were found to be 318?±?0.73 and 316?±?0.90 U/ml, respectively. The production of recombinant cutinases was increased by 11-fold as compared with T. fusca NRRL B-8184 wild-type strain. Both the recombinant cutinases were purified to homogeneity. They were found to be thermostable, organic solvent, and surfactant tolerant. Both the cutinase were active in a broad range of temperature (40–80 °C) and pH (6.8–9) with optimum activity at pH 8.0 and 55 °C.     

Synthesis and Characterization of Naphthalene‐Based Banana‐Shaped Liquid Crystals for Photoswitching Properties

A series of banana‐shaped monomers containing naphthalene as central units, azobenzene in side arms with terminal alkenes were synthesized and characterized. Polarizing optical microscopy, DSC and X‐ray diffraction measurements reveal that one compound processes a nematic phase while other four compounds exhibit B₆ phase. The absorption spectrum of trans‐azobenzene displays high‐intensity π‐π* transition at 365 and low‐intensity n‐π* transition at 450 nm. These molecules exhibit strong photoisomerisation behaviour in solutions in which trans to cis isomerisation takes 55 seconds whereas reverse process takes about 32 hours. Such a long thermal back relaxation is useful for creation of optical image storage devices.     

Groundwater dynamics of a saline impacted coastal aquifer of western Maharashtra,India: insights from a radiotracer study

This paper presents application of a radiotracer technique in coastal groundwater for assessing the aquifer dynamics, which is very crucial for understanding flow conditions of an aquifer and its vulnerability to salinity and other contamination. Groundwater dynamics in shallow and deep zones of Palghar Taluk located in west coast of Thane district were studied using point dilution method. ⁸²Br in the form of NH₄Br solution was used as the radiotracer and loggings were carried out by NaI (Tl) scintillation detector. From the analysis of the radiotracer activity loggings, it is found that shallow groundwater is relatively dynamic as compared to deeper groundwater at the two studied sites. The groundwater velocity is about 40–50 cm/day in the shallow zone while it is in the range of 4–40 cm/day in the deep zone. High salinity in deeper parts could be due to seawater intrusion through fractured basalt, which is diluted/flushed in the shallow zone by rain and river water. These findings are helpful in assessing groundwater dynamics in shallow and deep zones of this region and also on the impact of pumping activity on groundwater dynamics.     

MgSiO3 NPs catalyzed intramolecular cycloaddition reaction: A simple and stereoselective synthesis of unprecedented julolidine analogs

A new julolidine hybrid analogs have been accomplished in a regio and stereo controlled manner using heterogenous MgSiO₃ nanoparticles (NPs) catalyzed intramolecular dipolar cycloaddition reaction as a key step. The synthesized catalyst was used in the preparation of various new julolidine analogs with a good yield ranging from 65 to 85%. Further, catalyst could be recycled in several times without loss of significant activity which was an added advantage to the principles of green chemistry.     

Exclusive Formation of 1‐Aryl‐3‐(5‐nitro‐2‐furyl)‐4‐aroylpyrazoles via Regiospecific 1,3‐Dipolar Cycloaddition of 3‐Arylsydnones with α,β‐Acetylenic Ketones

1,3‐Dipolar cycloaddition of 3‐arylsydnones with α,β‐acetylenic ketones containing nitrofuran moiety has been studied, and it was observed that the dipolar cycloaddition is regiospecific, forming 1‐aryl‐3‐(5‐nitro‐2‐furyl)‐4‐aroylpyrazoles exclusively.     

Intramolecular Amidation: Synthesis of Novel Thiazole‐Fused Diazepinones

A new class of thiazole‐fused diazepinones has been synthesized by the application of intramolecular hydrazonolysis, wherein 2‐arylamino‐4‐coumarinyl‐5‐formyl thiazoles were treated with hydrazine hydrate in refluxing ethanol to yield the rearranged products via an interesting ring‐opening and cyclization process.     

Junjappa–Ila (JI) Heteroaromatic Annulation: A New General α‐Oxoketene Dithioacetals Mediated Inverse Method for Synthesis of Substituted Benzothiazoles

3‐(Methylthio)‐5‐oxo‐2‐(2‐phenyl‐1,3‐thiazol‐4‐yl)‐4,5‐substituted‐pent‐2‐enenitriles 3a–j were obtained in good yields by condensation of (2‐phenyl‐1,3‐thiazol‐4‐yl)‐acetonitrile (1) with various α‐oxoketene dithioacetals 2a–j in the presence of sodium hydride. The intermediates 3a–j underwent smooth cyclization in the presence of PTSA to afford the corresponding benzothiazoles 4a–j in moderate yields.     

Uptake study of tritiated water (HTO) by plants after long-term continuous normal release around Narora Atomic Power Station

Knowledge of the dynamics of HTO in leafy plant–soil system is required to verify models, such as the NORMTRI code, which predict environmental tritium following its release. Tritium concentrations in plants has been evaluated using the code NORMTRI and experimentally by collection of samples of different plants and their soils samples. In the present study, major seasonal crop plants i.e. wheat, mustard, sugar cane, coriander, spinach, potato, were collected beyond Narora Atomic Power Station site boundary and gular, arandi, neem, ashok, amaltas, csuarina leaf samples within NAPS site boundary for analysis of HTO content. Data analysis indicated that HTO in leaf is strongly influenced by atmospheric relative humidity and type of the plant.     

A mechanistic investigation of Biginelli reaction under base catalysis

The mechanism of the three component base mediated Biginelli dihydropyrimidines synthesis was investigated using Accurate Mass TOF LC-MS-ESI and Tandem TOF LC-MS-ESI. We suggest hemiaminal as a possible intermediate leading to the formation of Biginelli product. Under our current experimental conditions we did not observe any bis-ureide as reported by ji et al.