Browsing by Author "Joshi, Gaurav"

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Biodegradable nanoparticulate co-delivery of flavonoid and doxorubicin: Mechanistic exploration and evaluation of anticancer effect in vitro and in vivo
(Elsevier Ltd, 2021-07-30T00:00:00) Khan, Iliyas; Sarkar, Bibekananda; Joshi, Gaurav; Nakhate, Kartik T.; Ajazuddin; Mantha, Anil K.; Kumar, Raj; Kaul, Ankur; Chaturvedi, Shubhra; Mishra, Anil K.; Gupta, Umesh
The proposed study involves delivering drug/bioactive using a single nanoplatform based on poly lactic-co-glycolic acid (PLGA) for better efficacy, synergistic effect, and reduced toxicity. PLGA was conjugated to doxorubicin (D1), and this conjugate was used for encapsulation of naringenin (D2) to develop naringenin loaded PLGA-doxorubicin nanoparticles (PDNG). The PDNG NPs were 165.4 � 4.27 nm in size, having 0.112 � 0.035 PDI, with -10.1 � 2.74 zeta potential. The surface morphology was confirmed through transmission electron microscopy (TEM) and atomic force microscopy (AFM). The in vitro studies revealed that PDNG NPs exhibited selective anticancer potential in breast cancer cells, and induced apoptosis with S-phase inhibition via an increase in intrinsic reactive oxygen species (ROS) and altering the mitochondrial potential. The results also signified the efficient uptake of nanoparticles encapsulated drugs by cells besides elevating the caspase level suggesting programmed cell death induction upon treatment. In vivo studies results revealed better half-life (27.35 � 1.58 and 11.98 � 1.21 h for doxorubicin and naringenin) with higher plasma drug concentration. In vivo biodistribution study was also in accordance with the in vitro studies and in line with the in vivo pharmacokinetic. In vivo tumor regression assay portrayed that the formulation PDNG halts the tumor growth and lessen the tumor volume with the stable bodyweight of the mice. Conclusively, the dual delivery approach was beneficial and highly effective against tumor-induced mice. � 2021 The Author(s)
Design and synthesis of non-covalent imidazo[1,2-a]quinoxaline-based inhibitors of EGFR and their anti-cancer assessment
(MDPI AG, 2021-03-09T00:00:00) Kumar, Manvendra; Joshi, Gaurav; Arora, Sahil; Singh, Tashvinder; Biswas, Sajal; Sharma, Nisha; Bhat, Zahid Rafiq; Tikoo, Kulbhushan; Singh, Sandeep; Kumar, Raj
A series of 30 non-covalent imidazo[1,2-a]quinoxaline-based inhibitors of epidermal growth factor receptor (EGFR) were designed and synthesized. EGFR inhibitory assessment (against wild type) data of compounds revealed 6b, 7h, 7j, 9a and 9c as potent EGFRWT inhibitors with IC50 values of 211.22, 222.21, 193.18, 223.32 and 221.53 nM, respectively, which were comparable to erlotinib (221.03 nM), a positive control. Furthermore, compounds exhibited excellent antiproliferative activity when tested against cancer cell lines harboring EGFRWT; A549, a non-small cell lung cancer (NSCLC), HCT-116 (colon), MDA-MB-231 (breast) and gefitinib-resistant NSCLC cell line H1975 harboring EGFRL858R/T790M. In particular, compound 6b demonstrated significant inhibitory potential against gefitinib-resistant H1975 cells (IC50 = 3.65 �M) as compared to gefitinib (IC50 > 20 �M). Moreover, molecular docking disclosed the binding mode of the 6b to the domain of EGFR (wild type and mutant type), indicating the basis of inhibition. Furthermore, its effects on redox modulation, mitochondrial membrane potential, cell cycle analysis and cell death mode in A549 lung cancer cells were also reported. Copyright: � 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Design, synthesis and anticancer activity of 2-arylimidazo[1,2-a]pyridinyl-3-amines
(Academic Press Inc., 2021-11-01T00:00:00) Yadav, Umesh Prasad; Ansari, Arshad J.; Arora, Sahil; Joshi, Gaurav; Singh, Tashvinder; Kaur, Harsimrat; Dogra, Nilambra; Kumar, Raj; Kumar, Santosh; Sawant, Devesh M.; Singh, Sandeep
A series of imido-heterocycle compounds were designed, synthesized, characterized, and evaluated for the anticancer potential using breast (MCF-7 and MDA-MB-231), pancreatic (PANC-1), and colon (HCT-116 and HT-29) cancer cell lines and normal cells, while normal cells showed no toxicity. Among the screened compounds, 4h exhibited the best anticancer potential with IC50 values ranging from 1 to 5.5 ?M. Compound 4h caused G2/M phase arrest and apoptosis in all the cell lines except MDA-MB-231 mammosphere formation was inhibited. In-vitro enzyme assay showed selective topoisomerase II? inhibition by compound 4h, leading to DNA damage as observed by fluorescent staining. Cell signalling studies showed decreased expression of cell cycle promoting related proteins while apoptotic proteins were upregulated. Interestingly MDA-MB-231 cells showed only cytostatic effects upon treatment with compound 4h due to defective p53 status. Toxicity study using overexpression of dominant-negative mutant p53 in MCF-7 cells (which have wild type functional p53) showed that anticancer potential of compound 4h is positively correlated with p53 expression. � 2021 Elsevier Inc.
Design, synthesis, biological evaluation of 3,5-diaryl-4,5-dihydro-1H-pyrazole carbaldehydes as non-purine xanthine oxidase inhibitors: Tracing the anticancer mechanism via xanthine oxidase inhibition
(Academic Press Inc., 2021-01-07T00:00:00) Joshi, Gaurav; Sharma, Manisha; Kalra, Sourav; Gavande, Navnath S.; Singh, Sandeep; Kumar, Raj
Xanthine oxidase (XO) has been primarily targeted for the development of anti-hyperuriciemic /anti-gout agents as it catalyzes the conversion of xanthine and hypoxanthine into uric acid. XO overexpression in various cancer is very well correlated due to reactive oxygen species (ROS) production and metabolic activation of carcinogenic substances during the catalysis. Herein, we report the design and synthesis of a series of 3,5-diaryl-4,5-dihydro-1H-pyrazole carbaldehyde derivatives (2a-2x) as xanthine oxidase inhibitors (XOIs). A docking model was developed for the prediction of XO inhibitory activity of our novel compounds. Furthermore, our compounds anticancer activity results in low XO expression and XO-harboring cancer cells both in 2D and 3D-culture models are presented and discussed. Among the array of synthesized compounds, 2b and 2m emerged as potent XO inhibitors having IC50 values of 9.32 � 0.45 �M and 10.03 � 0.43 �M, respectively. Both compounds induced apoptosis, halted the cell cycle progression at the G1 phase, elevated ROS levels, altered mitochondrial membrane potential, and inhibited antioxidant enzymes. The levels of miRNA and expression of redox sensors in cells were also altered due to increase oxidative stress induced by our compounds. Compounds 2b and 2m hold a great promise for further development of XOIs for the treatment of XO-harboring tumors. � 2021 Elsevier Inc.
Dual inhibitors of epidermal growth factor receptor and topoisomerase IIa derived from a quinoline scaffold
(Royal Society of Chemistry, 2016) Chauhan, Monika; Joshi, Gaurav; Kler, Harveen; Kashyap, Archana; Amrutkar, Suyog M.; Sharma, Praveen; Bhilare, Kiran D.; Banerjee, Uttam C.; Singh, Sandeep; Kumar, Raj
Based on the quinazoline bearing EGFR inhibitors, a series of thirty four compounds having a quinoline scaffold were synthesised and evaluated in vitro for EGFR kinase inhibitory activity. A structure-activity relationship study revealed that 2,4-bis(arylamino) substituted quinolines possessed better anti-EGFR kinase activity. Compounds 3f and 3m emerged as potent EGFR kinase inhibitors (200 and 210 nM, respectively) and showed excellent anticancer activity at the micromolar level against a panel of cancer cell lines comparable to erlotinib. Furthermore, representative compounds inhibited the human topoisomerase II? selectively and catalytically, did not intercalate with DNA, increased intracellular ROS concentration (except 3m) and altered the mitochondrial membrane potential of the cancer cells. Cell cycle analysis and annexin-V staining in a lung cancer cell line showed that the compounds delayed cell cycle progression by inducing cell cycle arrest and subsequent apoptosis at the G1 phase. The facts were further corroborated through molecular modeling studies. ? 2018 The Royal Society of Chemistry.
Dynamic Axial Chirality in Drug Design and Discovery: Introduction to Atropisomerism, Classification, Significance, Recent Trends and Challenges
(Springer Singapore, 2021-02-18T00:00:00) Joshi, Gaurav; Kaur, Manpreet; Kumar, Raj
Induction of chirality in non-chiral ligands via involvement of hindered rotation around a single bond has led to the development of atropisomers. The atropisomers behave similarly as the chiral compounds and impact the drug discovery process. The chapter deals importantly with the brief introduction to this class, nomenclature descriptors, methods to measure atropisomers racemization, and the impact of atropisomers on drug discovery and includes relevant examples of drugs both from synthetic and natural origin. The chapter further extends to deal with various methodologies involved in atropselective conversions and regulatory guidelines involved in the development of atropisomers. � Springer Nature Singapore Pte Ltd. 2021.
Electro-organic synthesis of C-5 sulfenylated amino uracils: Optimization and exploring topoisomerase-I based anti-cancer profile
(Academic Press Inc., 2023-06-10T00:00:00) Rani, Payal; Chahal, Sandhya; Kumar, Roshan; Mayank; Kumar, Parvin; Negi, Arvind; Singh, Rajvir; Kumar, Sudhir; Kataria, Ramesh; Joshi, Gaurav; Sindhu, Jayant
Cancer is spreading worldwide and is one of the leading causes of death. The use of existing chemotherapeutic agents is frequently limited due to side effects. As a result, it is critical to investigate new agents for cancer treatment. In this context, we developed an electrochemical method for the synthesis of a series of thiol-linked pyrimidine derivatives (3a-3p) and explored their anti-cancer potential. The biological profile of the synthesized compounds was evaluated against breast (MDAMB-231 and MCF-7) and colorectal (HCT-116) cancer cell lines. 3b and 3d emerged to be the most potent agents, with IC50 values ranging between 0.98 to 2.45 �M. Target delineation studies followed by secondary anticancer parameters were evaluated for most potent compounds, 3b and 3d. The analysis revealed compounds possess DNA intercalation potential and selective inhibition towards human topoisomerase (hTopo1). The analysis was further corroborated by DNA binding studies and in silico-based molecular modeling studies that validated the intercalating binding mode between the compounds and the DNA. � 2023 Elsevier Inc.
Epidermal Growth Factor Receptor (EGFR) and its Cross-Talks with Topoisomerases: Challenges and Opportunities for Multi-Target Anticancer Drugs
(Bentham Science Publishers B.V., 2016) Chauhan, Monika; Sharma, Gourav; Joshi, Gaurav; Kumar, Raj
Background: The interactions of Epidermal Growth Factor Receptor (EGFR) and topoisomerases have been seen in various cancer including brain, breast, ovarian, colorectal, gastric, etc. Methods: The studies in adenocarcinoma patients, chromogenic in situ hybridization, western blotting, receptor binding assay and electromobility shift assays, etc. threw light on the biophysical and biochemical features of EGFR and Topoisomerase cross-talks. Results: It has been revealed that both the isomers of topoisomerase (Topo I and Topo II) interact via different mechanisms with EGFR. Topo II and HER2 share the same location i.e. 17q12-21 regions which could be a possible cause of predominant interactions seen between them. Topo I and EGFR interactions are mechanically related to the nucleolar translocation of heparenase by EGF and c-Jun. Conclusion: We compiled literature findings including the mechanistic interventions, signaling pathways, patents, in vitro and in vivo data of tested inhibitors and combinations in clinical trials, which provide convincing confirmations for the interactions of EGFR and topoisomerases. These interactions may be used for deriving a consistent route of mechanism, design and development of standard drug combinations and dual or multi inhibitors. ? 2016 Bentham Science Publishers.
Exploring insights of hydroxychloroquine, a controversial drug in Covid-19: An update
(Elsevier Ltd, 2021-03-18T00:00:00) Joshi, Gaurav; Thakur, Shikha; Mayank; Poduri, Ramarao
The review summarizes chloroquine (CQ) and its safer derivative hydroxychloroquine (HCQ) and its utility in Covid-19. Recently this well-established drug made its way back to the headlines during the SARS-CoV-2 pandemic. This led to an upsurge in the scientific arena with multiple research and review articles along with expert opinions and commentaries. The HCQ has received mixed judgements so far about its efficacy to be used in Covid-19 patients in a limited trial conducted all across the Globe. The purpose of our article is to put forth the history, pharmacodynamics, and pharmacokinetics, along with the existing studies favouring and disapproving the role of HCQ in the treatment of Covid-19. We grouped HCQ use at three stages, this includes HCQ for i. prophylactic use by asymptomatic health workers or peoples at higher risk; ii. patients having mild symptoms; iii. patients with extreme symptoms. The review critically discusses the underlying plausible reasons and mechanisms exploring HCQ in prophylactic management or treatment of SARS-CoV-2. Furthermore, we have critically analysed the reported pharmacokinetic parameters and compiled the proponent, opponent, or neutral opinions on the use of HCQ in Covid-19. Authors discretion is to conduct more studies considering the optimal dosing regimen and pharmacokinetics assessment. � 2021 Elsevier Ltd
Exploring the COVID-19 vaccine candidates against SARS-CoV-2 and its variants: where do we stand and where do we go?
(Taylor and Francis Ltd., 2021-12-03T00:00:00) Joshi, Gaurav; Borah, Pobitra; Thakur, Shweta; Sharma, Praveen; Mayank; Poduri, Ramarao
As of September 2021, 117 COVID-19 vaccines are in clinical development, and 194 are in preclinical development as per the World Health Organization (WHO) published draft landscape. Among the 117 vaccines undergoing clinical trials, the major platforms include protein subunit; RNA; inactivated virus; viral vector, among others. So far, USFDA recognized to approve the Pfizer-BioNTech (Comirnaty) COVID-19 vaccine for its full use in individuals of 16�years of age and older. Though the approved vaccines are being manufactured at a tremendous pace, the wealthiest countries have about 28% of total vaccines despite possessing only 10.8% of the total world population, suggesting an inequity of vaccine distribution. The review comprehensively summarizes the history of vaccines, mainly focusing on vaccines for SARS-CoV-2. The review also connects relevant topics, including measurement of vaccines efficacy against SARS-CoV-2 and its variants, associated challenges, and limitations, as hurdles in global vaccination are also kept forth. � 2021 Taylor & Francis Group, LLC.
Exploring the magic bullets to identify Achilles� heel in SARS-CoV-2: Delving deeper into the sea of possible therapeutic options in Covid-19 disease: An update
(Elsevier Ltd, 2020-11-27T00:00:00) Thakur, Shikha; Mayank; Sarkar, Bibekananda; Ansari, Arshad J.; Khandelwal, Akanksha; Arya, Anil; Poduri, Ramarao; Joshi, Gaurav
The symptoms associated with Covid-19 caused by SARS-CoV-2 in severe conditions can cause multiple organ failure and fatality via a plethora of mechanisms, and it is essential to discover the efficacious and safe drug. For this, a successful strategy is to inhibit in different stages of the SARS-CoV-2 life cycle and host cell reactions. The current review briefly put forth the summary of the SARS-CoV-2 pandemic and highlight the critical areas of understanding in genomics, proteomics, medicinal chemistry, and natural products derived drug discovery. The review further extends to briefly put forth the updates in the drug testing system, biologics, biophysics, and their advances concerning SARS-CoV-2. The salient features include information on SARS-CoV-2 morphology, genomic characterization, and pathophysiology along with important protein targets and how they influence the drug design and development against SARS-CoV-2 and a concerted and integrated approach to target these stages. The review also gives the status of drug design and discovery to identify the drugs acting on critical targets in SARS-CoV-2 and host reactions to treat Covid-19. � 2020 Elsevier Ltd
FDA approved fused pyrimidine-based drugs
(Elsevier, 2022-10-14T00:00:00) Thakur, Shikha; Ansari, Arshad J.; Joshi, Gaurav
The present chapter is a compilation and analysis of USFDA approved small drug candidates about fused pyrimidine pharmacophore. Out of 63 drugs approved so far, nearly 38% of drugs are approved for chemotherapeutic treatment of cancer. Further, antiviral category shares 19% followed by drugs for cardiovascular disorders (14%), inflammatory diseases (9%), respiratory disorders (6%), neurological disorders (5%), benign prostatic hypertrophy (3%), erectile dysfunction (2%), diabetes (2%) and thrombocytopenia (2%). The chapter further focuses on key biological targets affected by the reported drug and their pharmacological mechanism of action. We have also focused on elucidating key chemical taxonomy utilized in fused pharmacophores of pyrimidine. The analysis suggested purine nucleosides (11 drugs) and xanthines/hypoxanthines (11 drugs) share the major chunk utilized in drug development out of fused pyrimidine nucleus. � 2023 Elsevier Ltd. All rights reserved.
Imine/amide-imidazole conjugates derived from 5-amino-4-cyano-N1-substituted benzyl imidazole: Microwave-assisted synthesis and anticancer activity via selective topoisomerase-II-? inhibition
(Elsevier Ltd, 2015) Negi, Arvind; Alex, Jimi Marin; Amrutkar, Suyog M.; Baviskar, Ashish T.; Joshi, Gaurav; Singh, Sandeep; Banerjee, Uttam Chand; Kumar, Raj
Microwave-accelerated synthesis and anticancer activity of novel imine/amide-imidazole conjugates derived from 5-amino-4-cyano-N1-substituted benzyl imidazole against a panel of seven cancer cell lines are reported for the first time. Compounds ARK-4, 10 and 12 in the series show promising in vitro anti proliferative activity with low micromolar IC 50 values against A-459 (lung), Hep-G2 (liver) and H-460 (liver) cancer cell lines. Compounds caused the increase in ROS levels as well as mitochondrial membrane depolarization, which might induce apoptosis. Further, mechanistic interventions on biological and molecular modeling data supported that compounds inhibited topoisomerase-II selectively.- 2015 Elsevier Ltd. All rights reserved.
In Vivo Anticancer Evaluation of 6b, a Non-Covalent Imidazo[1,2-a]quinoxaline-Based Epidermal Growth Factor Receptor Inhibitor against Human Xenograft Tumor in Nude Mice
(MDPI, 2022-08-30T00:00:00) Bhat, Zahid Rafiq; Kumar, Manvendra; Sharma, Nisha; Yadav, Umesh Prasad; Singh, Tashvinder; Joshi, Gaurav; Pujala, Brahmam; Raja, Mohd; Chatterjee, Joydeep; Tikoo, Kulbhushan; Singh, Sandeep; Kumar, Raj
Tyrosine kinase inhibitors are validated therapeutic agents against EGFR-mutated non-small cell lung cancer (NSCLC). However, the associated critical side effects of these agents are inevitable, demanding more specific and efficient targeting agents. Recently, we have developed and reported a non-covalent imidazo[1,2-a]quinoxaline-based EGFR inhibitor (6b), which showed promising inhibitory activity against the gefitinib-resistant H1975(L858R/T790M) lung cancer cell line. In the present study, we further explored the 6b compound in vivo by employing the A549-induced xenograft model in nude mice. The results indicate that the administration of the 6b compound significantly abolished the growth of the tumor in the A549 xenograft nude mice. Whereas the control mice bearing tumors displayed a declining trend in the survival curve, treatment with the 6b compound improved the survival profile of mice. Moreover, the histological examination showed the cancer cell cytotoxicity of the 6b compound was characterized by cytoplasmic destruction observed in the stained section of the tumor tissues of treated mice. The immunoblotting and qPCR results further signified that 6b inhibited EGFR in tissue samples and consequently altered the downstream pathways mediated by EGFR, leading to a reduction in cancer growth. Therefore, the in vivo findings were in corroboration with the in vitro results, suggesting that 6b possessed potential anticancer activity against EGFR-dependent lung cancer. 6b also exhibited good stability in human and mouse liver microsomes. � 2022 by the authors.
Natural products based ayurvedic formulations: Chemical constituents and treatment in neurodegenerative disorders
(Bentham Science Publishers B.V., 2017) Muraleedharan, Ammu; Joshi, Gaurav; Kumar, Raj
Neurodegenerative diseases are linked with high morbidity and mortality rates. Medical science has made considerable progress in understanding the mechanisms associated with the development of the neurodegenerative diseases. Each neurodegenerative disease is associated with precise pathways of cell death with its own mechanisms that lead to the development of novel therapeutic strategies for each case. In spite of various western medicines available, there still remains too many complications to manage the progressive and severe symptoms of these diseases. Ayurveda is not the mainstream treatment system, but it can provide better results than mainstream medications, with less severe side effects. A detailed study, scientific validation and standardization of the active biomolecules of herbal-mineral formulations are required for the evolution of ayurvedic medicines. This review is a concerted effort to identify the major ayurvedic formulations and treatment strategies based on Ayurvedic literature for the treatment of neurodegenerative disorders. ? 2017 Bentham Science Publishers.
A Perspective on Medicinal Chemistry Approaches for Targeting Pyruvate Kinase M2
(American Chemical Society, 2021-11-02T00:00:00) Arora, Sahil; Joshi, Gaurav; Chaturvedi, Anuhar; Heuser, Michael; Patil, Santoshkumar; Kumar, Raj
The allosteric regulation of pyruvate kinase M2 (PKM2) affects the switching of the PKM2 protein between the high-activity and low-activity states that allow ATP and lactate production, respectively. PKM2, in its low catalytic state (dimeric form), is chiefly active in metabolically energetic cells, including cancer cells. More recently, PKM2 has emerged as an attractive target due to its role in metabolic dysfunction and other interrelated conditions. PKM2 (dimer) activity can be inhibited by modulating PKM2 dimer�tetramer dynamics using either PKM2 inhibitors that bind at the ATP binding active site of PKM2 (dimer) or PKM2 activators that bind at the allosteric site of PKM2, thus activating PKM2 from the dimer formation to the tetrameric formation. The present perspective focuses on medicinal chemistry approaches to design and discover PKM2 inhibitors and activators and further provides a scope for the future design of compounds targeting PKM2 with better efficacy and selectivity. � 2021 American Chemical Society
Pore-forming proteins and their role in cancer and inflammation: Mechanistic insights and plausible druggable targets
(Elsevier Ireland Ltd, 2022-08-30T00:00:00) Sankar, Jishnu; Arora, Sahil; Joshi, Gaurav; Kumar, Raj
Perforin is a granular effector pore-forming protein formed in NK cells and Cytotoxic T lymphocytes. These cytotoxic proteins are part of the first-line immune defense in the human body. They ensure apoptosis of pathogen-infected cells or tumor cells in the human body. Activation of receptors on NK cell or T cell triggers secondary proteins in these cells. Further, it leads to Ca2+ dependent perforin egress towards the target cell, ensued by PI3K signaling pathway. Perforin undergoes oligomerization over the target cell membrane and forms transmembrane pores with the membrane-spanning domain-MACPF domain. Granzymes, proapoptotic serine proteases are released through these pores and initiate the target cell apoptotic pathway leading to the cell death. Although perforin is a savior for humans from tumor and viral infections, uncontrolled expression of the perforins leads to the autoimmune conditions, including Familial Hemophagocytic lymphohistiocytosis, insulin-dependent diabetes, and cerebral myocarditis. The present review is the concerted effort to highlight the mechanistic pathways concerning perforin secretion, NK cell and T cell-mediated cytotoxicity towards virus-infected and transformed cells. This is followed by the discussion on synthetic derivatives tested so far to inhibit the perforin in pre and clinical arena for certain unusual conditions. � 2022 Elsevier B.V.
Precisely designed oxazolonaphthoimidazo[1,2-a]pyridine-based sensor for the detection of Fe3+ and DCP with cell imaging application
(Elsevier B.V., 2023-05-17T00:00:00) Kathuria, Vishal; Kiran; Rani, Payal; Mayank; Joshi, Gaurav; Kumar, Roshan; Sindhu, Jayant; Kumar, Parvin; Negi, Arvind; Kumar, Sudhir
Two new turn-off fluorescent sensors (V3 and V4) presented in the article revealed the potential application for the precise detection of Fe3+ and diethylchlorophosphate (DCP). These sensors include oxazolonaphthoimidazo[1,2-a]pyridine scaffold integrated with anthracene and pyrene-based framework. This design has facilitated the twisted intramolecular charge transfer (TICT) and planarised intramolecular charge transfer (PLICT) mechanisms, which were confirmed using computational and photophysical studies. The V3 and V4 fluorescent probes were particularly sensitive and highly selective for detecting Fe3+ and DCP analytes. For Fe3+, V3 and V4 undergo turn-off mechanism with the detection limit of 14.1 and 4.5 nM, respectively. Intracellular detection of Fe3+ via confocal live cell imaging was also demonstrated, showing its application under intracellular conditions. Our experimental data revealed the promises of V3 and V4 for instantaneous, accurate and on-spot monitoring of Fe3+ and DCP, even in the presence of other interfering analytes. � 2023 Elsevier B.V.
Precisely designed oxazolonaphthoimidazo[1,2-a]pyridine-based sensor for the detection of Fe3+ and DCP with cell imaging application
(Elsevier B.V., 2023-05-17T00:00:00) Kathuria, Vishal; Kiran; Rani, Payal; Mayank; Joshi, Gaurav; Kumar, Roshan; Sindhu, Jayant; Kumar, Parvin; Negi, Arvind; Kumar, Sudhir
Two new turn-off fluorescent sensors (V3 and V4) presented in the article revealed the potential application for the precise detection of Fe3+ and diethylchlorophosphate (DCP). These sensors include oxazolonaphthoimidazo[1,2-a]pyridine scaffold integrated with anthracene and pyrene-based framework. This design has facilitated the twisted intramolecular charge transfer (TICT) and planarised intramolecular charge transfer (PLICT) mechanisms, which were confirmed using computational and photophysical studies. The V3 and V4 fluorescent probes were particularly sensitive and highly selective for detecting Fe3+ and DCP analytes. For Fe3+, V3 and V4 undergo turn-off mechanism with the detection limit of 14.1 and 4.5 nM, respectively. Intracellular detection of Fe3+ via confocal live cell imaging was also demonstrated, showing its application under intracellular conditions. Our experimental data revealed the promises of V3 and V4 for instantaneous, accurate and on-spot monitoring of Fe3+ and DCP, even in the presence of other interfering analytes. � 2023 Elsevier B.V.
Pyrimidine containing epidermal growth factor receptor kinase inhibitors: Synthesis and biological evaluation
(Blackwell Publishing Ltd, 2017) Joshi, Gaurav; Nayyar, Himanshu; Kalra, Sourav; Sharma, Praveen; Munshi, Anjana; Singh, Sandeep; Kumar, Raj
Structure-based design and synthesis of pyrimidine containing reversible epidermal growth factor receptor (EGFR) inhibitors 1a?d are reported. The compounds (1a?d) inhibited the EGFR kinase activity in vitro with IC50 range 740?nm to 3??m. mRNA expression of EGFR downstream target genes, that is twist, c-fos and aurora were found to be altered upon treatment with compounds 1a?d. The compounds 1a?d exhibited excellent anticancer activity at low micromolar level (3.2?9??m) in lung, colon and breast cancer cell lines. Furthermore, compounds induced the alteration in mitochondrial membrane potential and reactive oxygen species level and. Selected compound 1b was found to increase sub-G1 population indicative of cell death, the mode of cell death was apoptotic as evident from Annexin V verses propidium iodide assay. Molecular modelling further helped to investigate the binding recognition pattern of the compounds in ATP binding EGFR domain similar to erlotinib and dissimilar to WZ4002. ? 2017 John Wiley & Sons A/S.