The Synthesis and Biological Evaluation of Regioisomeric Benzothiazolyl Coumarins

Various 4-aryloxymethylcoumarins have been obtained by the r.t. allylic substitution with formylphenols. These have been further reacted with o-aminothiophenol resulting in the formation of a benzothiazole skeleton. These compounds have been synthesised with a view to study their potential as microbial growth inhibitors. Comparative studies on the spectral and antimicrobial activities have also been carried out.     

Reusable zinc oxide nanoflowers for the synthesis of α-aminophosphonates under solvent-free ultrasonication

A simple wet chemical method is used to prepare zinc oxide nanoflowers (ZnO NFs) which were subjected to various characterization techniques such as XRD, FTIR, UV–Vis, FE-SEM, and XPS. XRD pattern indicates pure, crystalline, and monodispersed form with hexagonal wurtzite phase. The 3-D flower shape morphology with hexagonal ZnO nanorods was confirmed in FE-SEM. The synthesized ZnO NFs was used to study catalytic behavior in Kabachnik–Fields reaction under controlled ultrasound cavitation technique. High surface-to-volume ratio of ZnO NFs and the effect of ultrasonication enhances the yield of α-aminophosphonate. The catalyst was recycled and reused four times without any significant loss of its catalytic activity. Moreover, existing method becomes attractive and practical due to its easy, clean, fast, cost-effective, and eco-friendly procedure.     

Investigations on thermoelectric power of lanthanum oxide doped ferroelectric sodium vanadate

The thermoelectric power of ferroelectric sodium vanadate doped with different concentrations of lanthanum oxide has been measured in the temperature range covering their transition temperatures. It has been observed that the thermoelectric power increases with temperature, attains maximum value and with further increase in the temperature decreases to zero, indicating Curie temperature of the respective samples; however, it changes the sign for higher temperature. The thermoelectric power of sodium vanadate increases to maximum with increase in doping concentration of lanthanum oxide from 0.025 to 0.1 mol%; however, it decreases for higher concentrations. Pure as well as lanthanum oxide doped sodium vanadate samples showp-type behaviour in the ferroelectric region andn-type behaviour in the paraelectric region.     

Chemical Fingerprinting and Quantification of Biomarker Wedelolactone in Different Sources of “Bhringaraja” by High-Performance Thin-Layer Chromatography and Method Validation

JPC – Journal of Planar Chromatography – Modern TLC - Two different botanical sources, Eclipta alba and Wedelia calen-dulacea are used as “Bhringaraja” in the Ayurvedic...     

Micropatterning of Covalently Attached Biotin on Poly(lactic acid) Film Surfaces

A two‐step approach was used to micropattern covalently attached biotin on the surface of poly(lactic acid) (PLA) film. Poly(acrylic acid) (PAA) was micropatterned on PLA using photolithography in step 1, followed by carbodiimide wet chemistry to covalently attach biotin to acid groups in step 2. The PAA micropatterning reaction progression was monitored using attenuated total reflectance‐Fourier transform infrared (ATR‐FT‐IR) spectroscopy, water contact angle goniometry, and atomic force microscopy (AFM). The PAA‐biotin conjugation reaction characterization using XPS confirmed the carbodiimide mediated amidation reaction. The resultant PLA film was then immersed into a solution of fluorescence‐conjugated streptavidin and examined under fluorescence microscopy to reveal various micropatterns

     

Mentha arvensis essential oil suppressed airway changes induced by histamine and ovalbumin in experimental animals

The present investigation aimed to evaluate the activity of the essential oil of Mentha arvensis L. on exogenously induced bronchoconstriction in experimental animals. The anti-asthmatic effect of M. arvensis essential oil (MAEO) was studied using histamine aerosol-induced bronchoconstriction in guinea pigs and ovalbumin (OVA) sensitised albino mice. Treatment with M. arvensis oil significantly (p < 0.001) increased the time of preconvulsive dyspnoea in histamine-induced guinea pigs. Oral treatment of MAEO significantly (p < 0.001) decreased absolute eosinophil count, serum level of IgE and the number of eosinophils, neutrophils in BALF. Histopathological examination of lungs showed that essential oil rescinded bronchial asthma. The present investigation provides evidence that MAEO relaxes bronchial smooth muscles and suppressed immunological response to OVA.     

Synthesis of new α-aminophosphonates using nanoscale nickel-based metal–organic framework as a heterogeneous catalyst and their antibacterial activity

An elegant approach was presented for the synthesis of novel α-aminophosphonates: a three-component one-pot condensation of 3-(trifluoromethyl)aniline, substituted aromatic aldehydes, and diethyl phosphite using a nickel-based metal–organic framework (Ni-MOF). The Ni-MOF was synthesized using 4,4′-biphenyldicarboxylic acid and further characterized using various techniques such as X-ray diffraction, Fourier-transform infrared, thermogravimetry/differential thermal analysis, Brunauer–Emmett–Teller, and field-emission scanning electron microscopy analyses. Ni-MOF seems to be an eco-friendly, an easily recyclable, and heterogeneous catalyst up to the eighth run with minimal reduction in its catalytic activity. The synthesized α-aminophosphonates were also investigated for antibacterial and antioxidant activities. In few cases, compounds 4a–4x show similar as well as higher antibacterial activity. Among the synthesized α-aminophosphonates, 4a–4x had more potent antibacterial activity against pathogenic bacteria while compounds 4h, 4m, 4n, 4q, 4u, 4v, and 4w exhibited significant antioxidant activity.