Computational study of new 1,2,3-triazole derivative of lithocholic acid: Structural aspects, non-linear optical properties and molecular docking studies as potential PTP 1B enzyme inhibitor.

We have reported synthesis of a novel 1,2,3-triazole conjugate of lithocholic acid by 1,3-dipolar cycloaddition reaction. The molecular properties such as geometry, conformations, bond lengths and dihedral angles were investigated theoretically. The bond order analysis was performed using Wiberg bond order (WBO), Fuzzy bond order (FBO) and Laplacian bond order (MBO) method. Electronic properties of molecule such as electrostatic surface potential analysis, frontier molecular orbital analysis, reduced density gradient, total density of states, and global chemical reactivity indices have been investigated. The nonlinear optical properties were also investigated. Total dipole moment, mean polarizability and hyperpolarizability were found to be much higher than standard urea molecule which suggests that it could act as potential NLO material. The molecular docking calculations are also performed to investigate its potential as PTP 1B enzyme inhibitor.

A green, multicomponent, regio- and stereo-selective 1,3-dipolar cycloaddition of azides and azomethine ylides generated in situ with bifunctional dipolarophiles using PEG-400.

A series of novel dispiropyrrolidine-linked 1,2,3-triazole derivatives have been prepared by one-pot, four-component protocol that employed 5-arylidene-3-(prop-2-ynyl)thiazolidine-2,4-dione, isatin, sarcosine and substituted azides using Cu(I) generated in situ as catalyst in PEG-400 as a highly efficient and green media. This is the first report of a four-component reaction involving a classical Huisgen reaction, in which the two dipolar moieties (substituted azides and in situ generated azomethine ylides) react with acetylenic and olefinic dipolarophiles, respectively. The 1,3-dipolar cycloaddition proceeds in a highly regio- and stereo-selective manner. This methodology can be an ideal tool for the preparation of biologically important five-membered heterocyclic compounds in one pot.

Synthesis, biological activities and SAR studies of novel 1-Ethyl-7-methyl-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid based diacyl and sulfonyl acyl hydrazines.

BACKGROUND: Diacyl hydrazines have attracted significant interest in medicine, pesticide chemistry and material science. It is an important class of insect growth regulators. In this study, acyl hydrazine, the essential active group was incorporated in to nalidixic acid with the aim of combining the active groups to generate more potent agrochemical. RESULTS: Various nalidixic acid based diacyl and sulphonyl acyl hydrazines derivatives were synthesized and characterized by spectral techniques. These compounds were screened for the antifungal activity against five pathogenic fungi, nitrification inhibitory activity and insect growth regulator (IGR) activity against Spodoptera litura. The fungicidal activity was screened against R. bataticola, S. rolfsii, R. solani, F. oxysporum and A. porri. Most of the compounds showed moderate to good antifungal activity against A. porri (ED50 = 29.6-495.9 µg/mL). All the compounds showed significant nitrification inhibitory activity at 5% level. IGR activity was examined by feeding method against S. litura. CONCLUSION: The study revealed that a few compounds possessed good activity against three different pests namely certain fungus, soil bacteria and insect, among which, compound 37 (R' = 4-chlorophenyl) behaved the best.

Synthesis, antimicrobial evaluation and QSAR analysis of novel nalidixic acid based 1,2,4-triazole derivatives.

Novel nalidixic acid based 1,2,4-triazole derivatives were synthesized and characterized using spectral techniques like (1)H NMR, (13)C NMR, IR and mass spectrometry. All these compounds were screened for antimicrobial activity against five bacteria and two pathogenic fungi. Most of these compounds showed better antimicrobial activity than the parent compound, 4-amino-5-mercapto-1,2,4-triazole. Among all the screened compounds, 3-{6-(2-chlorophenyl)-1,2,4-triazolo [3,4-b] [1,3,4]thiadiazol-3-yl}-1-ethyl-7-methyl-1,8-naphthyridin-4(1H)-one (23) was emerged as promising antimicrobial agent (MIC = 16 µg/mL). Quantitative structure activity relationship (QSAR) analysis was carried out using various distance-based topological indices, steric and hydrophobic parameters. Based on the QSAR analysis it is indicative that lipophilic and steric parameters are the pre-requisites for these molecules to act as potent antimicrobial agents.

Synthesis of nalidixic acid based hydrazones as novel pesticides.

Thirty-one substituted hydrazones of nalidixic acid hydrazide were synthesized and characterized by spectral techniques. These compounds were evaluated for various biological activities, namely, fungicidal, insecticidal, and nitrification inhibitory activities. The antifungal activity was evaluated against five pathogenic fungi, namely, Rhizoctonia bataticola , Sclerotium rolfsii , Rhizoctonia solani , Fusarium oxysporum , and Alternaria porii . They showed maximum inihibition against A. porii with ED(50) = 34.2-151.3 microg/mL. The activity was comparable to that of a commercial fungicide, hexaconazole (ED(50) = 25.4 microg/mL). They were also screened for insecticidal activity against third-instar larvae of Spodoptera litura and adults of Callosobruchus maculatus and Tribollium castaneum . Most of them showed 70-100% mortality against S. litura through feeding method at 0.1% dose. These compounds were not found to be effective nitrification inhibitors.

In-gel detection of urease activity by nitroprusside-thiol reaction.

A new staining method for urease activity in non-denaturing polyacrylamide gels is described. The increase in local pH of the gel, resulting from ureolytic activity of urease, causes a purple red coloured band after incubation of the polyacrylamide gel with urea. Staining of urease activity using this method is very specific for catalytically active urease even in crude preparations. Detection of urease activity by this method is rapid, simple and economical. The described method is also more sensitive than existing methods of urease staining. A minimum of 0.25 mU of urease activity can be detected after 5 min of incubation with the substrate. The method has been used to demonstrate the presence of different charge isoforms of urease in a member of the plant family Cucurbitaceae.