Showing papers by "Badiadka Narayana published in 2016"
TL;DR: In this paper, the formation of colloidal silver nanoparticles was determined and confirmed by different characterization techniques i.e. UV-visible spectroscopy, transmission electron microscope (TEM), dynamic light scattering and EDAX.
Abstract: The silver nanoparticles were synthesized (AgNPs) under incandescent light at room temperature using aqueous silk fibroin obtained from Bombyx mori silk used as green stabilizer. The formation of colloidal AgNPs were determined and confirmed by different characterization techniques i.e. UV–visible spectroscopy, transmission electron microscope (TEM), dynamic light scattering and EDAX. The UV–visible spectroscopy showing a characteristic surface plasmon resonance band at 432 nm. The FTIR spectra confirms the presence of functional groups, the TEM images confirmed that the synthesized nanoparticles were spherical in shape with smooth surfaces. The particle diameter was around 35–40 nm. Further, the x-ray diffraction analysis confirms the nanocrystalline phase of silver with face centered cubic crystal structure. The synthesized colloidal silver nanoparticles exhibits potential antibacterial activity against Gram positive and Gram negative bacteria i.e. Bacillus subtilis, Staphylococcus aureus, Salmonella typhi and Escherichia coli.
37 citations
TL;DR: The colloidal silver nanoparticles (AgNPs) were synthesized in situ under white light at room temperature using aqueous silk fibroin (SF) obtained from Bombyxmori silk.
Abstract: The colloidal silver nanoparticles (AgNPs) were synthesized in situ under white light at room temperature using aqueous silk fibroin (SF) obtained from Bombyxmori silk. The UV-visible spectroscopy revealed the formation of AgNPs by showing a typical surface Plasmon resonance (SPR) band at 422 nm from the UV-visible spectra. The transmission electron microscope (TEM) images show that the formed nanoparticles were spherical in shape with smooth surfaces. The particle diameter was around 35-40 nm. Further the X-ray diffraction (XRD) analysis confirms the nanocrystalline phase of silver with face centered cubic (FCC) crystal structure. The biogenic silver nanoparticles exhibited significant antibacterial activity against human bacterial pathogens Bacillus subtilis, Staphylococcus aureus, Salmonella typhi and Escherichia coli.
36 citations
TL;DR: In this paper, a density functional theory (DFT) based analysis of 4-Amino-3-(4-hydroxybenzyl)-1H-1,2,4-triazole-5(4H)-thione (4AHT) has been theoretically analyzed.
33 citations
TL;DR: A combined experimental and theoretical analysis of on molecular structure, vibrational spectra and HOMO-LUMO analysis of 1-{3-(4-chlorophenyl)-5-[4-(propan-2-yl)phenyl]-4,5-dihydro-1 H -pyrazol-1-yl}-ethanone is reported.
27 citations
TL;DR: New functionalized N-heterocyclic derivatives were synthesized from an itaconic anhydride (ITA) precursor and characterized by spectral and analytical data and showed strong antibacterial activity and potential antifungal activity.
19 citations
TL;DR: In this article, the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy of (2 E )-1-(4-Chlorophenyl)-3-[4-(propan 2-yl)phenyl]prop-2-en-1-one.
14 citations
9 citations
TL;DR: The Mannich reaction is a three-component reaction of an aldehyde, a primary or secondary amine and a ketone which is one of the most powerful C-C bond forming reactions in organic synthesis as discussed by the authors.
Abstract: The Mannich reaction is a three-component reaction of an aldehyde, a primary or secondary amine and a ketone which is one of the most powerful C-C bond forming reactions in organic synthesis. It leads to β-amino carbonyl compounds, which are useful for the syntheses of nitrogen containing compounds, such as natural products and medicinally relevant compounds. The versatility and potential of these compounds to introduce both functional and structural diversity using the Mannich reaction have stimulated the creativity of chemists. Keeping in view of the importance of this organic moiety in the field of medicine and biology here an attempt has been made to review the synthesis and biological importance of heterocyclic Mannich base derivatives.
6 citations
TL;DR: In this paper, two simple and selective visible spectrophotometric methods were developed for assay of bifonazole in pure drug and in its pharmaceutical formulation, which were based on the charge transfer complexation reaction.
4 citations
TL;DR: In this paper, the crystal structures of (2E)-1-(anthracen-9-yl)-3-(4-nitrophenyl) prop-2-en-1-ones were solved by direct methods and refined by full-matrix least-square procedures to a final R value of 0.0468 and 0.0486.
Abstract: (2E)-1-(anthracen-9-yl)-3-(4-chlorophenyl)prop-2-en-1-ones and (2E)-1-(anthracen-9-yl)-3-(4-nitrophenyl) prop-2-en-1-ones crystallize in the monoclinic crystal system with space group P2 1
/c. Single-crystal X-ray diffraction data for both the compounds were collected on an X’Calibur CCD area detector diffractometer (Oxford Diffraction) using MoKa radiation (λ= 0.7107 A) at 293(2) K. The crystal structures were solved by direct methods and refined by full-matrix least-square procedures to a final R value of 0.0468 [I] and 0.0486 [II]. The crystal structures as elucidated by X-ray diffraction methods show the presence of a few intermolecular interactions, and the nature and energetics associated with these interactions have been characterized using PIXEL software.
4 citations
TL;DR: In this paper, a new, simple, accurate and rapid spectrophotometric method was developed for the quality control of febantel (FBT), in pure and dosage forms.
TL;DR: Four simple and precise spectrophotometric methods were developed and optimized for the assay of glipizide (GPZ) in pure form and in its pharmaceutical preparations and were found to be selective for the quantitative determination of GPZ in commercially available formulations.
Abstract: Four simple and precise spectrophotometric methods were developed and optimized for the assay of glipizide (GPZ) in pure form and in its pharmaceutical preparations. Method A was based on the reaction of drug with 1,2-naphthoquinone-4-sulfonate (NQS) in alkaline medium to form orange colored product (λmax 456 nm). In the method B, drug reduced the reagent tetrazolium blue (TB) which lead to the formation of intense violet colored formazan (λmax 515 nm). The method C employed Folin-Ciocalteu reagent (FC) that reacted with drug in alkaline medium to form blue colored complex (λmax 760 nm). Method D was based on the reduction of iron(III) to iron(II) by the drug and their complexation with bathophenanthroline (BPT) to form pink colored complex (λmax 547 nm). Linearity of Beer’s plots was observed in the concentration range of 10.00 – 100.00 μg mL, 2.00 – 22.00 μg mL, 5.00 – 40.00 μg mL, 0.50 – 7.50 μg mL for method A, B, C and D respectively. The proposed methods were validated and values of analytical parameters like molar absorptivity, Sandell’s sensitivity, limits of detection and quantification were also calculated. The methods were found to be selective for the quantitative determination of GPZ in commercially available formulations.
TL;DR: The title compound, 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2]-ethenyl] benzamide:N,N-dimethylformamide (1: 1), (C15H11N3O2S2 · C3H7NO), was synthesized and its structure was established by spectral analysis and X-ray diffraction studies as mentioned in this paper.
Abstract: The title compound, 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethenyl] benzamide:N,N-dimethylformamide (1: 1), (C15H11N3O2S2 · C3H7NO), was synthesized, and its structure was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the monoclinic space group P21/n with a = 10.8714(7), b = 9.0497(5), c = 19.8347(13) A, β = 91.093(5)°, Z = 4. The crystal structure is stabilized by N–H···S, C–H···O and N–H···O hydrogen bonds. The π···π interactions are also observed between the rings.
TL;DR: The molecules of 2-(4-chlorophenyl)-N-(pyrazin-2-yl)acetamide are linked into complex sheets built solely from hydrogen bonds.
Abstract: In the crystal of 2-(4-chlorophenyl)-N-(2-iodophenyl)acetamide, C14H11ClINO, molecules are linked by a combination of N—H⋯O and C—H⋯O hydrogen bonds to form a C(4)C(4)[R21(7)] chain of rings and chains of this type are linked by a combination of C—Cl⋯π(arene) and C—I⋯π(arene) interactions to form deeply puckered twofold interwoven sheets. In the crystal of 2-(4-chlorophenyl)-N-(pyrazin-2-yl)acetamide, C12H10ClN3O, molecules are linked into complex sheets by N—H⋯N, C—H⋯N and C—H⋯O hydrogen bonds, and by C—H⋯π(arene) interactions.
TL;DR: In this paper, new sensitive spectrophotometric methods are developed for the determination of sulfadoxine (SFD) based on the reaction of drug with aryl aldehyde followed by Co(II) chloride in the acidic medium.
TL;DR: In this paper, the imidazole ring of C22H17N3O2S has dihedral angles of 9.2, 10.9 and 12.5 degrees with the thio-phene, phenyl and methoxy-substituted benzene rings.
TL;DR: Comparisons are made with some related structures, indicating that a hydrogen-bonded R2(2)(10) ring is the common structural motif.
Abstract: 4-Antipyrine [4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one] and its derivatives exhibit a range of biological activities, including analgesic, antibacterial and anti-inflammatory, and new examples are always of potential interest and value. 2-(4-Chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C19H18ClN3O2, (I), crystallizes with Z′ = 2 in the space group P\overline{1}, whereas its positional isomer 2-(2-chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, (II), crystallizes with Z′ = 1 in the space group C2/c; the molecules of (II) are disordered over two sets of atomic sites having occupancies of 0.6020 (18) and 0.3980 (18). The two independent molecules of (I) adopt different molecular conformations, as do the two disorder components in (II), where the 2-chlorophenyl substituents adopt different orientations. The molecules of (I) are linked by a combination of N—H⋯O and C—H⋯O hydrogen bonds to form centrosymmetric four-molecule aggregates, while those of (II) are linked by the same types of hydrogen bonds forming sheets. The related compound N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-(3-methoxyphenyl)acetamide, C20H21N3O3, (III), is isomorphous with (I) but not strictly isostructural; again the two independent molecules adopt different molecular conformations, and the molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds to form ribbons. Comparisons are made with some related structures, indicating that a hydrogen-bonded R22(10) ring is the common structural motif.
TL;DR: In this article, the imidazole ring is shown to have dihedral angles of 4.6 and 20.2° with the thio-phene and iso-propyl-benzene rings, respectively.
Journal Article•
TL;DR: In the crystal a combination of N—H ⋯O and asymmetric bifurcated O—H⋯(N,O) hydrogen bonds link the molecules into a three-dimensional network.
Abstract: In the title compound, C21H17N3O3S, the non-H atoms, apart from those in the benzoyl group, are almost coplanar (r.m.s. deviation = 0.049 A) and the benzoyl group is almost orthogonal to the plane of the rest of the molecule [dihedral angle = 80.34 (6)°]. In the crystal, a combination of N—H⋯O and asymmetric bifurcated O—H⋯(N,O) hydrogen bonds link the molecules into a three-dimensional network. Weak C—H⋯O interactions are also observed.
TL;DR: In this paper, the editor-in-chief has retracted this article because it significantly overlaps with a previously published article from the same authors, and the other authors have not responded to correspondence regarding this retraction.
Abstract: Retraction Note: The Editor-in-Chief has retracted this article [1] because it significantly overlaps with a previously published article from the same authors [2]. Yallappa Sangappa disagrees with this retraction. The other authors have not responded to correspondence regarding this retraction.
TL;DR: A combination of O—H⋯N hydrogen bonds and C—Cl⋬π(pyridyl) interactions links the molecules of the title compounds into (100) sheets.
Abstract: In the title racemic compound, C12H10ClNO, the dihedral angle between the benzene and pyridine rings is 74.34 (6)°. In the crystal, the molecules are linked by O—H⋯N hydrogen bonds, forming zigzag C(5) [001] chains in which alternating R- and S-configuration molecules are related by c-glide symmetry. In addition, inversion-related pairs of molecules are linked into dimers by pairs of weak C—Cl⋯π(pyridyl) interactions, which link the hydrogen-bonded chains into (100) sheets. Structural comparisons are drawn with a number of related compounds.