Browsing by Author "Mamata Singh"

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2-Methoxy-N′-(morpholin-4-ylcarbono-thio-yl)benzohydrazide hemihydrate
(2007) N.K. Singh; Mamata Singh; Ajay K. Srivastava; Anuraag Shrivastav; R.K. Sharma
In the title compound, C13H17N3O3S·0.5H2O, the morpholine ring adopts a chair conformation. The conformation of the mol-ecule is stabilized by intra-molecular N - H⋯O and N - H⋯S hydrogen bonds. Inter-molecular N - H⋯O and O - H⋯O hydrogen bonds link the organic mol-ecules through the water mol-ecules to build up a channel running parallel to the c axis and containing the water mol-ecules. © International Union of Crystallography 2007.
Benzyl N′-(2-methoxy-benzo-yl)hydrazine-carbo-dithio-ate
(2007) N.K. Singh; Mamata Singh; Ray J. Butcher
The title dithio ester, C16H16N2O2S2, was synthesized by the reaction of potassium N′-(2-methoxy-benzo-yl)hydra-zine-carbodithio-ate and benzyl chloride in chloro-form. The dihedral angle between the 2-methoxy-phenyl ring and the benzyl ring is 85.06 (2) Å. In the crystal structure, intra- and inter-molecular hydrogen bonding stabilizes the mol-ecule and the crystal packing. © International Union of Crystallography 2007.
Enhanced in vitro therapeutic efficacy of triphenyltin (IV) loaded vitamin E TPGS against breast cancer therapy
(Elsevier Ltd, 2022) Mamata Singh; Nishant Kumar Rana; Madaswamy S. Muthu; Abhishek Jha; Tushar S. Basu Baul; Biplob Koch
Triphenyltin (Ph3SnL (IV) is a synthetic hydrophobic compound functionalized with a diazo and amino group having potentials to use in anticancer chemotherapy, but its hydrophobic property hindrance the therapeutic efficacy for wider use against cancer treatment. Therefore, in our present work we aimed to develop TPGS micelles loaded with Ph3SnL (IV) to enhanced the therapeutic efficacy in breast cancer cells as compare to docetaxel. Solvent casting method was employed to develop TPGS-Ph3SnL1 (IV), TPGS-Ph3SnL5 (IV) and TPGS-DTX micelles to increase the aqueous solubility of hydrophobic drugs. The size of TPGS-Ph3SnL1 (TSD-30-F) and TPGS-Ph3SnL5 (TSD-34-F) micelles were initially evaluated by dynamic light scattering which were found to be below 50 nm. The morphological characteristics of micelles were observed by TEM, SEM and AFM respectively. Further, drug encapsulation and in vitro drug release profiles of micelles were assessed using dialysis bag diffusion technique under sink condition at pH7.4 at 37 °C over 72 h and analysed through UV–visible spectrophotometry. The anticancer efficacy of TSD-30-F, TSD-34-F and DTX-F were tested against two breast cancer cell lines (MCF-7 and MDA-MB-231) and cervical cancer cell line (HeLa) by MTT assay. IC50 values of TSD-30-F and TSD-34-F displayed very high activity towards breast cancer cells as compared to DTX-F, while moderate in case of HeLa cells. Acridine orange/ethidium bromide as well as flow cytometry observation delineates that micelles induced apoptotic mode of cell death after elevating intracellular reactive oxygen level. Higher cellular uptake of micelles in breast cancer cells was evaluated through TPGS-coumarin6 as compared to coumarin6 without TPGS. Therefore, our study suggests that TPGS micelles may increase therapeutics efficacy of Ph3SnL (IV) in breast cancer cells and can be a promising candidate for targeted drug delivery against breast cancer cells. © 2022 Elsevier Ltd
Exploring Untouched Variant of Bis(2-methyl-1H-indol-3-yl)methane: Enhances Chemo and Mono-Selectivity
(John Wiley and Sons Inc, 2024) Ravikumar Merneedi; Mamata Singh; Manoj Kumar Bharty
The new derivatives of bis(2-methyl-1H-indol-3-yl)methane are synthesized by employing decanoic acid to boost aldehyde reactivity via electrophilic activation. The reactions entail combining 2-methyl-1H-indole with various aromatic, aliphatic, and heterocyclic aldehydes at room temperature for 24 h. The newly synthesized compound 4-(bis(2-methyl-1H-indol-3-yl)methyl)-3-bromophenol f) has been characterized through 2D structure elucidation. Chemo selectivity and mono selectivity have been explored. © 2024 Wiley-VCH GmbH.
Formulation and in vitro evaluation of upconversion nanoparticle-loaded liposomes for brain cancer
(Newlands Press Ltd, 2020) Narendra; Abhishesh Kumar Mehata; Matte Kasi Viswanadh; Roshan Sonkar; Datta Maroti Pawde; Vishnu Priya; Mamata Singh; Biplob Koch; Madaswamy S Muthu
Aim: This work focused on the development of transferrin-conjugated theranostic liposomes consisting of docetaxel (DXL) and upconversion nanoparticles for the diagnosis and treatment of gliomas. Materials & methods: Upconversion nanoparticles and docetaxel-loaded theranostic liposomes were prepared by a solvent injection method. Formulations were analyzed for physicochemical properties, encapsulation efficiency, drug release, elemental analysis, cytotoxicity and fluorescence. Results: The particle size was around 200 nm with spherical morphology and an encapsulation efficiency of up to 75.93%, was achieved for liposomes with an in vitro drug release of 71.10%. The IC50 values demonstrated enhanced cytotoxicity on C6 glioma cells with targeted liposomes in comparison with nontargeted liposomes. Conclusion: Prepared theranostic liposomes may be promising for clinical validation after an in vitro and in vivo evaluation on cell lines and animals, respectively. © 2020 Future Medicine Ltd.. All rights reserved.
Gold liposomes for brain-targeted drug delivery: Formulation and brain distribution kinetics
(Elsevier Ltd, 2021) Roshan Sonkar; Sonali; Abhishek Jha; Matte Kasi Viswanadh; Ankita Sanjay Burande; Narendra; Datta Maroti Pawde; Krishna Kumar Patel; Mamata Singh; Biplob Koch; Madaswamy S. Muthu
This work was aimed to formulate transferrin (Tf) receptor targeted gold based theranostic liposomes which contain both docetaxel (DCX) and glutathione reduced gold nanoparticles (AuGSH) for brain-targeted drug delivery and imaging. AuGSH was prepared by reducing chloroauric acid salt using glutathione. The co-loading of DCX and AuGSH into liposomes was achieved by the solvent injection technique, and Tf was post-conjugated on the surface of the liposomes using carboxylated Vit-E TPGS (TPGS-COOH) as a linker. The liposomes were characterized for various parameters such as size, shape, surface charge, and drug release. The Tf receptor targeted gold liposomes were evaluated for the cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based colorimetric assay and in-vitro qualitative cellular uptake studies using confocal microscopy. The in-vivo site specific delivery of DCX was analyzed by the brain distribution study of DCX in comparison with marketed formulation (Docel™). A sustained drug release of about 70% was observed from liposomes in the span of 72 h. The in-vivo results demonstrated that targeted gold liposomes were able to deliver DCX into the brain by 3.70, 2.74 and 4.08-folds higher than Docel™ after 30, 120 and 240 min of the treatment, respectively. Besides, the results of these studies have suggested the feasibility of Tf decorated AuGSH and DCX co-loaded liposomes as a promising platform for targeted nano-theranostics. © 2020 Elsevier B.V.
Mn(II) complexes of N0-(2-methoxybenzoyl)hydrazine carbodithioic acid ethyl ester: Synthesis, spectral and structural characterization
(2012) Mamata Singh; Manoj K. Bharty; Aarti Singh; Sujata Kashyap; Udai P. Singh; Nand K. Singh
Two new Mn(II) complexes [Mn(Hmbhce)2- (o-phen)] (1) and [Mn(Hmbhce) 2(bpy)] (2) based on N0-(2- methoxybenzoyl)hydrazine carbodithioic acid ethyl ester (H2mbhce) have been synthesized by reacting Mn(OAc)2- 4H2O with H2mbhce in the presence of o-phen/bpy. The complexes have been characterized by elemental analyses, magnetic susceptibility measurement, IR, UV-Vis and single crystal X-ray data. Both complexes [Mn(Hmbhce)2- (o-phen)] and [Mn(Hmbhce)2(bpy)] crystallize in monoclinic system with space group P 21/c and P 21/n, respectively. The single crystal X-ray structures of 1 and 2 show that the Mn(II) center is bonded with two (Hmbhce)- through carbonyl oxygen and deprotonated hydrazinic nitrogen, plus two nitrogen atoms from one o-phen/bpy coligand. The crystal structures of complexes 1 and 2 are stabilized by weak intramolecular N-H⋯O hydrogen bonding and C-H⋯p interactions giving supramolecular architectures. © Springer Science+Business Media B.V. 2012.
N 2-[Bis(benzylsulfanyl)methylene]-2-methoxybenzohydrazide
(2007) N.K. Singh; Mamata Singh; Ray J. Butcher
The title compound, C23H22N2O2S2, was obtained from the reaction of potassium N′-(2-methoxy-benzo-yl)hydrazinecarbodithio-ate and benzyl chloride. Strong intra-molecular N - H⋯O and N - H⋯S hydrogen bonds are observed. Weak inter-molecular C - H⋯O inter-actions link mol-ecules into a two-dimensional framework; C - H⋯π inter-actions are also observed. © International Union of Crystallography 2007.
Novel pyrimido-pyridazine derivatives: design, synthesis, anticancer evaluation and in silico studies
(Newlands Press Ltd, 2022) Priyanka Sonker; Mamata Singh; Manisha Nidhar; Vishal Prasad Sharma; Priyanka Yadav; Rashmi Singh; Biplob Koch; Ashish Kumar Tewari
Aim: A novel pyrimido-pyridazine derivative for developing anticancer agents was synthesized via Ullmann arylation using an efficient Cu(OAc)2 catalyst. Materials & methods: Compounds were investigated for their anticancer potential, against human breast adenocarcinoma cells, viz. MCF-7, MDA-MB-231 and normal cell line HEK-293. Further, an in vivo study was conducted on lymphoma-bearing mice while in silico analysis was carried out for molecular interactions. Results: Compound 2b displayed significant antitumor activity towards MDA-MB-231 cells through induction of apoptosis and arresting cells in S-phase in vitro, while it significantly increased the lifespan and reduced tumor growth in vivo. An in silico study revealed potent tyrosine-protein kinase inhibitors. Conclusion: Taken together the molecule has the potential to become an effective therapeutic treatment for breast cancer. © 2022 Newlands Press.
One pot hydrothermal synthesis of fluorescent NP-carbon dots derived from Dunaliella salina biomass and its application in on-off sensing of Hg (II), Cr (VI) and live cell imaging
(Elsevier B.V., 2019) Ankit Kumar Singh; Vikas Kumar Singh; Mamata Singh; Prabhakar Singh; Sk. Riyazat Khadim; Urmilesh Singh; Biplob Koch; S.H. Hasan; R.K. Asthana
The impact of hazardous chemicals and toxic metal ions in the environment played havoc to the ecosystem. In the present work green chemistry approach was applied for one-step hydrothermal synthesis of nitrogen, phosphorus dual doped carbon dots, utilizing green precursor i.e, biomass of halophilic microalgae Dunaliella salina (algal derived nitrogen phosphorous carbon dots i.e A-NPCDs). Synthesized A-NPCDs were characterized through TEM, FT-IR, P-XRD, DLS and XPS. It showed appreciable optical properties with significant fluorescence quantum yield (8%)and exhibited blue color under UV – light (λ ex = 365 nm). A-NPCDs acted as fluorescent turn off sensor for toxic metal ion such as Hg (II) and Cr (VI) with good selectivity and sensitivity. Interestingly, ANPCDs detected Cr (VI) up to 0.018μM which was below the permissible level of Cr (VI) in drinking water. Such sensing resulted because of combination of inner filter effect and dynamic quenching mechanism. Moreover, it also showed good selectivity (0.018μM) for Hg (II) via dynamic quenching mechanism. MTT assay of A-NPCDs on HEK-293 cell line showed biocompatibility with negligible cytotoxicity. Therefore, these were successfully employed for live cell imaging and intracellular detection of Hg (II) and Cr (VI) in HEK-293 cell line. Thus, green synthesized A-NPCDs may be a good alternative for chemically derived CDs in intracellular detection of Hg (II) and Cr (VI) of a complex biological environment. © 2019
Syntheses and X-ray structural studies of the novel complexes [Ni(en)2(3-pyt)2] and [Cu(en)2](3-pyt)2 based on 5-(3-pyridyl)-1,3,4-oxadiazole-2-thione
(Elsevier Ltd, 2008) Mamata Singh; R.J. Butcher; N.K. Singh
Two novel mononuclear mixed-ligand complexes [Ni(en)2(3-pyt)2] (1) and [Cu(en)2](3-pyt)2 (2), derived from potassium [N′-(pyridine-3-carbonyl)-hydrazinecarbodithioate [K+(H2L)-] and containing en as a co-ligand, have been synthesized. The [K+(H2L)-] undergoes cyclization in the presence of ethylenediamine (en) and is converted to 5-(3-pyridyl)-1,3,4-oxadiazole-2-thione (3-pyt)-. [Ni(en)2(3-pyt)2] and [Cu(en)2](3-pyt)2 have been characterized with the aid of elemental analyses, IR, UV-Vis, magnetic susceptibility and single crystal X-ray studies. The complexes 1 and 2 crystallize in the orthorhombic and monoclinic systems with space groups Pca2(1) and C2/c, respectively. The single crystal X-ray diffraction studies of both complexes indicate that (3-pyt)- adopts a thione form in 1 but is present as a thiolato form in 2. © 2008 Elsevier Ltd.
Synthesis of a new N,N′-ethane-1,2-bis(4-methoxyphenyl)carbothioamide ligand and its Cu(I) and Ag(I) complexes
(Elsevier Ltd, 2008) Nand K. Singh; Mamata Singh; Pratibha Tripathi; Ajay K. Srivastava; Ray J. Butcher
[Cu(H2L)(PPh3)2]NO3 · 0.5H2O (2) and [Ag(H2L)(PPh3)2]NO3 · 0.5H2O (3) complexes of a new flexible thioamide ligand; N,N′-ethane-1,2-bis(4-methoxyphenyl)carbothioamide H2L (1) have been synthesized using PPh3 as a coligand. The synthesized compounds have been characterized with the help of elemental analyses, IR, 1H, 13C and 31P NMR spectroscopy. The ligand and its Cu(I) complex have been studied by single crystal X-ray crystallography. The ligand acts as a neutral S-donor and forms a nine-membered chelate ring in [Cu(H2L)(PPh3)2]NO3 · 0.5H2O. The molecular packing is stabilized by an anionic cavity formed by intermolecular hydrogen bonding between the basal plane of the complex molecule and the nitrate ions. The square shaped columnar channel has dimensions of 5.489(25) [N(11)-H(11A)⋯O(13)⋯H(21A)N(21)] × 3.693(7) [N(11)-C(11)-C(21)-N(21)] Å. © 2007 Elsevier Ltd. All rights reserved.
Synthesis, characterization and spectroscopic studies of a new ligand [N′-(2-methoxybenzoyl)hydrazinecarbodithioate] ethyl ester and its Mn(II) and Cd(II) complexes: X-ray structural study of Mn(II) complex
(Elsevier Ltd, 2009) Mamata Singh; Vaibhave Aggarwal; Udai P. Singh; Nand K. Singh
A new dithioligand [N′-(2-methoxybenzoyl)hydrazinecarbodithioate] ethyl ester (H2mbhce, 1) formed complexes [M(Hmbhce)2]n {M = Mn(II), Cd(II)} which have been characterized with the help of elemental analyses, magnetic susceptibility measurements, IR, UV-Vis, 1H and 13C NMR and mass spectrometry. [Mn(Hmbhce)2]n (2) crystallized in monoclinic system with space group P21/n. In the polymeric structure of 2, the ligand acts as an uninegative tridentate N(1), O(1), S(3) donor and forms a five membered chelate ring with N(1), C(2) and O(1). The intermediate bond lengths (between single and double bond distances) O(1)-C(2) = 1.241(3), N(2)-C(2) = 1.325(3), N(1)-N(2) = 1.393(2), N(1)-C(8) = 1.311(3) Ǻ and C(8)-S(3) = 1.704(2) Å suggest considerable delocalization of charge which develops slightly aromatic character in the chelate ring. © 2008 Elsevier Ltd. All rights reserved.
TPGS loaded triphenyltin (IV) micelles induced apoptosis by upregulating p53 in breast cancer cells and inhibit tumor progression in T-cell lymphoma bearing mice
(Elsevier Inc., 2022) Mamata Singh; Virendra Singh; Tushar S. Basu Baul; Biplob Koch
Aims: Currently, breast cancer is one of the most frequently diagnosed and the second leading cause of cancer related deaths in women worldwide. Our present study aimed to investigate the major mechanistic effects of micelles (TSD-30-F, TSD-34-F) on breast cancer cells as well as their antitumor efficacy in in vivo DL bearing BALB/c mice. Methods: Apoptotic death by micelles was investigated by mitochondrial aggregation, membrane potential and DNA fragmentation assay in MCF-7 and MDA-MB-231 cells. Molecular mode of action of micelles were determined by RT-PCR and western blot analysis, drug-ligand interaction was analyzed by in silico methods, while, in vivo antitumor activity was investigated by Kaplen-Meier survival curve, T/C value, body weight and belly size of BALB/c mice. Key findings: TSD-30-F and TSD-34-F micelles displayed significant apoptotic induction. At molecular level, TSD-30 and TSD-34 micelles showed up-regulation of p53, Bax, Bak, Caspase-3 and down-regulation of Bcl-2 genes as well as proteins in tested breast cancer cells. In silico analysis revealed that TSD-30 and TSD-34 showed efficient binding affinity with p53, Caspase-3, Bax and Bcl-2 proteins. Significant in vivo antitumor efficacy was exhibited by the micelles formulations by increasing life span with reduced bodyweight and belly size growth pattern in BALB/c mice compared to DTX-F micelles. Significance: Our results suggest that triphenyltin (IV) micelles could be a very promising therapeutic candidate for treatment of breast cancer patients and occupy a new place in targeted breast cancer therapeutic. © 2022 Elsevier Inc.
Triethylammonium N′-(benzylsulfanylthiocarbonyl)-2- hydroxybenzohydrazidate
(2008) Mamata Singh; Ajay K. Srivastava; N.K. Singh; Anuraag Shrivastav; R.K. Sharma
In the title compound, C6H16N+·C15H13N2O2S2 -, the thione S atom is in a cis configuration with respect to the phenyl and benzene rings, while it adopts a trans configuration with respect to the carbonyl group. The dihedral angle between the benzene and phenyl rings is 78.81 (2)°. The mol-ecular conformation is stabilized by intra-molecular O - H⋯O and N - H⋯S hydrogen bonds, while inter-molecular N - H⋯O, N - H⋯N and weak C - H⋯O inter-actions help to stabilize the crystal structure. © International Union of Crystallography 2008.
White Light Emitting Gadolinium Oxide Nanoclusters for In-vitro Bio-imaging
(John Wiley and Sons Inc, 2022) Vivek Kumar Verma; Prachi Srivastava; Shivesh Sabbarwal; Mamata Singh; Biplob Koch; Manoj Kumar
Fluorescent probes are highly desirable for accurate diagnosis and play a crucial role in the optical imaging modality. Here, ultrafine (1.2 nm) nanoclusters of undoped gadolinium oxide were synthesized via a simple, one-pot technique using water as the reaction medium. Prepared nanoclusters exhibit strong tuneable emission spanning from 400-620 nm (extended visible region) with broad full width at half maximum of (FWHM) ∼140 nm, resulting in white light emission (WLE). Cytotoxicity studies revealed nearly 100 % cell viability encouraging its application in cell imaging. These nanoclusters possessed distinctive properties such as wide-range pH stability, ionic tolerability, durable photostability, and anomalous colloidal stability (more than 24 months). This brief report uses white light-emitting gadolinium oxide (Gd2O3) nanoclusters as an optical probe for in-vitro fluorescence imaging. © 2022 Wiley-VCH GmbH.
White light-emitting, biocompatible, water-soluble metallic magnesium nanoclusters for bioimaging applications
(Institute of Physics, 2023) Prachi Srivastava; Vivek Kumar Verma; Shivesh Sabbarwal; Mamata Singh; Kedar Sahoo; Biplob Koch; Manoj Kumar
Ultra-small (1.6 nm), water-soluble, white light-emitting (WLE), highly stable (∼8 months) BSA templated metallic (Mg0) nanoclusters (fluorescent magnesium nanoclusters = FMNCs) is developed using the green and facile route. Synthesis was facilitated by the reduction of magnesium salt, where template bovine serum albumin is utilized as a reducing agent and ascorbic acid act as a capping agent to impart stability in water, thereby obtaining stabilized Mg0 nanoclusters In solution, stabilized Mg0 nanoclusters produce white light (450-620 nm with FWHM ∼120 nm) upon 366 nm light excitation. This white light emission was found to have a CIE coordinate of 0.30, 0.33 [pure white light CIE (0.33, 0.33)]. Taking advantage of WLE and ultrasmall size, FMNCs were used for in vitro fluorescence imaging of HaCaT cell lines, yielding blue (τ = 2.94 ns, with a relative of QY = 1.2 % w.r.t QS), green (τ = 3.07 ns; relative quantum yield of 4.6% w.r.t R6G) and red (τ = 0.3 ns) images. Further, incubation of FMNCs with HEK293 (Human embryonic kidney cell) and cancerous MDA-MB-231 (Breast cancer cell line) human cell lines yielded 100 % cell viability. Current work is envisioned to contribute significantly in the area of science, engineering, and nanomedicine. © 2022 IOP Publishing Ltd.