Publications by authors named "Ashok Dongamanti"

6 Publications

  • Page 1 of 1

Facile synthesis, characterization and enhanced catalytic reduction of 4-nitrophenol using NaBH by undoped and Sm, Gd, Hf doped LaO nanoparticles.

Nano Converg 2019 Apr 10;6(1):12. Epub 2019 Apr 10.

Department of Chemistry, Osmania University, Hyderabad, TS, 500007, India.

This work focuses on the synthesis of undoped and doped lanthanum oxide nanoparticles (LaO NPs) by a simple co-precipitation method for the catalytic reduction of 4-nitrophenol (4-NP) using NaBH as a reducing agent. Their optical properties, morphologies, structure, chemical compositions and electronic properties were carefully characterized by XRD, FTIR, SEM, TEM, PL and UV-visible absorption spectroscopy. The SEM and TEM images showed various shape morphologies and sizes of the particles. The XRD pattern revealed a polycrystalline nature with the hexagonal structure of the LaO NPs. The synthesized undoped and doped LaO NPs were also employed as catalysts for the reduction of 4-nitrophenol, it shows that the doped (Sm, Gd and Hf) LaO NPs provided better catalytic activity than the undoped LaO NPs. Moreover, Hf doped LaO NPs exhibited an enhanced catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol in 90 min. The catalytic conversion was studied by UV-vis spectroscopy with high reduction rate (k = 2.048 min). The applications of the present study may utilize in the removal of toxic pollutants in a cleaning of environmental pollution as well as in industrial applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40580-019-0181-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6456637PMC
April 2019

Conventional and microwave-assisted synthesis of new indole-tethered benzimidazole-based 1,2,3-triazoles and evaluation of their antimycobacterial, antioxidant and antimicrobial activities.

Mol Divers 2018 Nov 18;22(4):769-778. Epub 2018 Apr 18.

Department of Chemistry, Green and Medicinal Chemistry Laboratory, Osmania University, Hyderabad, Telangana, 500007, India.

A new series of triheterocycles containing indole-benzimidazole-based 1,2,3-triazole hybrids have been synthesized in good yields via a microwave-assisted click reaction. All the compounds were characterized by IR, [Formula: see text] NMR, [Formula: see text] NMR and mass spectroscopy and were evaluated for their in vitro antitubercular activity against the Mycobacterium tuberculosis H37Rv strain. Compounds 4b, 4h and 4i displayed highly potent antitubercular activity with MIC 3.125-6.25 [Formula: see text]. The antioxidant potential was evaluated using 2,2-diphenyl-1-picryl hydrazine and [Formula: see text] radical scavenging activity, and compounds 4e,4f and 4g showed excellent radical scavenging activity with [Formula: see text] values in the range of 08.50-10.05 [Formula: see text]. Furthermore, the compounds were evaluated for antimicrobial activity against numerous bacterial and fungal strains, and compounds 4b, 4c and 4h were found to be the most promising potential antimicrobial molecules with MIC 3.125-6.25 [Formula: see text].
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11030-018-9828-1DOI Listing
November 2018

Microwave-assisted synthesis, antioxidant and antimicrobial evaluation of 2-indolinone-based bis-1,2,3-triazole derivatives.

Mol Divers 2018 Feb 7;22(1):57-70. Epub 2017 Nov 7.

Green and Medicinal Chemistry Laboratory, Department of Chemistry, Osmania University, Hyderabad, 500007, India.

A series of 2-indolinone-based bis-1,2,3-triazole derivatives have been synthesized in excellent yields via microwave-assisted, copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction of O-, N-propargylated indolinone derivatives with in situ generated organic azides. The antioxidant activity of the synthesized compounds was evaluated by DPPH, NO and [Formula: see text] radical scavenging methods. Among the compounds screened for antioxidant activity, compounds 5e, 5f and 5o showed excellent radical scavenging activity more than the standard drugs ascorbic acid and BHT. The synthesized compounds were evaluated for their antimicrobial activity against gram-positive and gram-negative bacterial and fungal strains. Compounds 5g, 5h, 5n, 5q and 5r were found to be the most promising microbial growth inhibitory molecules.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11030-017-9791-2DOI Listing
February 2018

Bis-spirochromanones as potent inhibitors of Mycobacterium tuberculosis: synthesis and biological evaluation.

Mol Divers 2017 Nov 24;21(4):999-1010. Epub 2017 Aug 24.

X-ray Crystallography Division, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana State, 500 007, India.

On the basis of reported antimycobacterial property of chroman-4-one pharmacophore, a series of chemically modified bis-spirochromanones were synthesized starting from 2-hydroxyacetophenone and 1,4-dioxaspiro[4.5] decan-8-one using a Kabbe condensation approach. The synthesized bis-spirochromanones were established based on their spectral data and X-ray crystal structure of 6e. All synthesized compounds were evaluated against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain, finding that some products exhibited good antimycobacterial activity with minimum inhibitory concentration as low as [Formula: see text]. Docking studies were carried out to identify the binding interactions of compounds II, 6a and 6n with FtsZ. Compounds exhibiting good in vitro potency in the MTB MIC assay were further evaluated for toxicity using the HEK cell line.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11030-017-9779-yDOI Listing
November 2017

Design, synthesis, molecular-docking and antimycobacterial evaluation of some novel 1,2,3-triazolyl xanthenones.

Medchemcomm 2017 Mar 3;8(3):559-570. Epub 2017 Jan 3.

Molecular Modeling and Medicinal Chemistry Group , Department of Chemistry , Osmania University , Hyderabad , Telangana-500 007 , India.

As part of an ongoing effort to develop new antitubercular and antimicrobial agents, a series of substituted xanthenone derivatives () were synthesized. Xanthenone derivatives () were prepared a one-pot three-component thermal cyclization reaction of β-naphthol (), substituted 1-aryl-1-[1,2,3]triazole-4-carbaldehydes (), and cyclic-1,3-diones (, ) in the presence of a catalytic amount of iodine. The newly synthesized compounds were characterized by IR, NMR, mass spectral data, and elemental analysis. These compounds ( and ) were screened for antitubercular activity against the HRv (ATCC 27294) strain, for antibacterial activity against Gram-positive and Gram-negative strains, and for antifungal activity against a pathogenic strain of fungi. Among the compounds tested, most of them showed good to excellent antimicrobial and antitubercular activity. The active compounds displaying good potency in the MTB were further examined for toxicity in a HEK cell line. In addition, the structure and antitubercular activity relationship were further supported by molecular-docking studies of the active compounds against the pantothenate synthetase (PS) enzyme of .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c6md00593dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6072411PMC
March 2017

Synthesis, antimicrobial activity and molecular docking of novel tetracyclic scaffolds incorporating a flavonoid framework with medium sized oxygen heterocycles.

Bioorg Med Chem Lett 2015 Feb 30;25(4):898-903. Epub 2014 Dec 30.

Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India.

A convenient approach for the synthesis of novel tetracyclic scaffolds incorporating a flavonoid framework with medium sized heterocyclic rings (eight-, nine-, ten- and eleven-membered rings) containing two oxygen atoms from flavonols through alkylation using different dibromoalkanes was described. The synthesized compounds were established based on the spectral data and X-ray crystal structure for 6c. The synthesized compounds were evaluated for their in vitro antimicrobial activity. Docking studies were carried out for most active two compounds 6f and 6i.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bmcl.2014.12.066DOI Listing
February 2015
-->