Jitendra Singh

Synthesis of bioactive spiro-2-[3′-(2′-phenyl)-3H-indolyl]-1-aryl-3-phenylaziridines and SAR studies on their antimicrobial behavior

The present communication deals with synthesis of a new series of spiro-2-[3′-(2′-phenyl)-3H-indolyl]-1-aryl-3-phenylaziridines. Infrared (IR), 1H nuclear magnetic resonance (NMR), mass spectral, and elemental analysis data corroborated the structure of all synthesized compounds. Synthesized compounds were screened for antimicrobial activity against a representative panel of Gram-positive and Gram-negative bacteria. All newly synthesized compounds showed remarkable antimicrobial behavior. Structure–activity relationship (SAR) investigations were applied to investigate the correlation between the molecular refractive index (MR) parameter of the compounds and their biological activity profile. All compounds were subjected to acute toxicity studies to determine 50% lethal dose (LD50) values.

Development of an electrochemical sensor based on Schiff base for Cu(II) determination at nano level in river water and edible materials

Plasticised membranes using 2-[{(2-hydroxyphenyl)imino}methyl]-phenol (L1) and 2-[{(3-hydroxyphenyl)imino}methyl]-phenol (L2), have been prepared and investigated as Cu2+ ion-selective sensors. Effect of various plasticisers, namely, dibutyl phthalate (DBP), dibutyl sebacate (DBS), benzyl acetate (BA), o-nitrophenyloctylether (o-NPOE) and anion excluders, oleic acid (OA) and sodium tetraphenylborate (NaTPB) was studied and improved performance was observed in several instances. Optimum performance was observed with membranes of (L1) having composition L1 : DBS : OA : PVC in the ratio of 6 : 54 : 10 : 30 (w/w, %). The sensor works satisfactorily in the concentration range 3.2 × 10−8–1.0 × 10−1 mol L−1 with a Nernstian slope of 29.5 ± 0.5 mV decade−1 of a cu2+ . The detection limit of the proposed sensor is 2.0 × 10−8 mol L−1 (1.27 ng mL−1). Wide pH range (3.0–8.5), fast response time (7 s), sufficient (up to 25% v/v) non-aqueous tolerance and adequate shelf life (3 months) indicate the utility of the proposed sensor. The potentiometric selectivity coefficients as determined by matched potential method indicate selective response for Cu2+ ions over various interfering ions, and therefore could be successfully used for the determination of copper in edible oils, tomato plant material and river water.

A novel approach to the synthesis of 1,2,3-triazoles and their SAR studies

A series of biologically active 4-acetyl-2-aryl-5-methyl-1-vinyl-2,3-dihydro-1H-1,2,3-triazole derivatives has been synthesized. The compounds were synthesized in excellent yields (80–85%) and the structures were established on the basis of corresponding IR, 1H NMR, and elemental analysis data. The purity has been ascertained on the basis of chromatographic resolution using acetic acid-toluene (4:6 v/v) as binary eluent. All the compounds (4a–l) have been tested for their antifungal activity against a representative panel of fungal microbes. These synthesized compounds exhibited significant activities against A. niger, C. albicans, C. azyma, and A. flavus. For all the tests conducted, voriconazole was used as the control drug. The hydrophobic parameter (log P) also has been quantized for correlation of structure with biological activity, and a critical evaluation of structure-activity relationship (SAR) has been performed.Graphical AbstractThe paper delineates the novel synthesis of substituted highly significant triazoles. A large number of various substituted 1,2,3-triazole derivatives have been synthesized in a facile manner. Further, All the compounds have been tested for their antimicrobial activity against a representative panel of fungi with the aim to search for new chemical entities, which can be envisaged as the potent antifungal agents.