Senior Researcher with a demonstrated history of working in the higher education institutes. Skilled in Biotechnology, Cancer Research, Animal handling, Life Sciences, and Pharmaceutical. Strong research professional with a Master of Science (Specialization in Advanced Genetics & Molecular Biology). Hand on experience and knowledge of various Biophysical techniques such as Ultraviolet–visible spectroscopy, Circular dichroism (CD) spectroscopy, Fluorescence spectroscopy, Isothermal titration calorimetry (ITC), Molecular docking, simulations, FTIR, NMR, Cell culture techniques. Data analysis experience using specific software and use of various sources including related databases of publications and internet resources.
EDUCATION
Dr. Sagar Bag ( Former CSIR UGC NET SRF; DST-INSPIRE Fellow; University of Calcutta) is currently working as a Senior researcher. His research mainly focuses on different aspects of Genetics & Molecular Biological Techniques, Biophysical chemistry, Non-canonical DNA. Senior Researcher with a demonstrated history of working in the higher education institutes. Skilled in Biotechnology, Cancer Research, Animal handling, Life Sciences & Pharmaceutical research.
RESEARCH, TEACHING, or OTHER INTERESTS
Multidisciplinary, Biochemistry, Genetics and Molecular Biology, Biophysics, Molecular Medicine
33
Scopus Publications
704
Scholar Citations
13
Scholar h-index
14
Scholar i10-index
Scopus Publications
Impact of Polystyrene Microplastics on Human Alternative DNA Structures Sagar Bag, Souvik Ghosal, Sudipta Bhowmik Chemistryselect, 2026 The widespread contamination of the environment by microplastics (MPs), particularly polystyrene (PS) and polyethylene (PE), poses significant ecological and health concerns. While much attention has been given to the physical impact of MPs, their molecular interactions, particularly with genetic material, remain largely unexplored. This study examines how PS and PE MPs influence the structure and stability of human alternative i‐motif (iM) DNA, which plays a key role in regulating gene expression and maintaining genomic integrity. Using biophysical techniques, our results have demonstrated the effects of PS‐MPs and PE‐MPs of different sizes on HRAS2 iM DNA. Our results reveal that PS‐MPs, particularly those with a 100 nm diameter, strongly interact with HRAS2 iM DNA, causing hypochromism and shifts in the UV‐Vis spectra, along with changes in secondary structure observed by CD. FT‐IR spectroscopy confirmed alterations in DNA conformation, and thermal melting data showed increased stability of the HRAS2 iM DNA in the presence of PS‐MPs. These findings suggest that PS‐MPs, due to their small size, may disrupt the structural integrity of iM DNA, potentially affecting gene regulation. This work highlights the need to consider both the physical and biochemical properties of MPs in assessing their environmental and health risks.
Naphthalene Diimide-Based Soft Materials Exhibiting High-Performance, Tunable Electrical Properties Through Side-Chain Engineering and Strong Binding Interactions with Human Hemoglobin Sk Shamim Ahamed, Nargis Khatun, Mangal Deep Burman, Sagar Bag, Rajdeep Chakraborty, Bodhisattwa Panda, Raj Kumar Chinnadurai, Suman Kumar Ghosh, Debashree Manna, Sudipta Bhowmik, A K M Maidul Islam, Muklesur Rahman, Tapas Ghosh Small, 2025 Herein the design and synthesis of naphthalene diimide (NDI) derivatives aminated at the core with N1,N1‐dimethylpropane‐1,3‐diamine, and 6‐aminocoumarin are reported. Accommodating amine substituents on the electron‐poor NDI scaffold yielded notable electronic characteristics of interest. These aminated NDIs exhibited two distinct absorption bands: one at a high‐energy band (350–450 nm) associated with π–π* transitions and the other one (450–600 nm) due to intramolecular charge transfer absorption. The obtained bandgaps, ranging from 2.69 to 3.34 eV depending on side‐chain modifications, demonstrated tunability, indicating varied semiconducting properties. Electrical studies revealed that all the side‐chain‐modified molecules exhibited high electrical conductivity and displayed characteristics of Schottky diodes. Notably, different Schottky parameters are found to vary systematically based on side‐chain engineering, aligning well with their optical characteristics. Complementarily, AFM, and XRR investigations revealed unique crystalline morphologies associated with molecular architecture, highlighting the efficacy of molecular engineering in optimizing materials for electrical devices. Selective compounds underwent a series of biophysical analyses, including UV–vis absorption‐, fluorescence‐, and circular dichroism spectroscopy, all of which demonstrated a strong binding affinity, highlighting their potential interactions with human hemoglobin (Hb). In‐depth computational studies like TDDFT and frontier molecular orbital analysis cemented the experimental observations.
Nickel-Catalyzed Regioselective Access to Dibenzo[b,e]Azepinones: Mechanistic Study, Docking, and Biophysical Exploration of Binding Interactions with Human Hemoglobin Sk Shamim Ahamed, Uma Sankar Mandal, Sagar Bag, Mangal Deep Burman, Rabindranath Lo, Debashree Manna, Sudipta Bhowmik, Tapas Ghosh Chemistry an Asian Journal, 2025 A nickel‐catalyzed intramolecular acetylene hydroarylation process has been described to produce dibenzo[b,e]azepin‐6‐one derivatives in an effective, regioselective manner. This procedure demonstrates a broad substrate scope and exceptional tolerance to various functional groups. Mechanistic insights were confirmed through the use of the density functional theory method. Selective synthesized compounds were subjected to biophysical analysis such as UV–vis absorption spectroscopy, fluorescence spectroscopy, stoichiometric analysis, thermal melting, and circular dichroism spectroscopic analysis revealing strong binding affinity to exploit their interactions with human hemoglobin (Hb). Additionally, molecular docking studies provided insights into the interactions between the synthesized molecule and human Hb.
Modulation of the HRAS1 I-motif DNA Promoter Region by Dietary Plant Flavonoid Kaempferol Sagar Bag, Souvik Ghosal, Mangal Deep Burman, Moupriya Mukherjee, Goutam Pramanik, Sudipta Bhowmik ACS Omega, 2025 ). Time-resolved fluorescence decay and circular dichroism data support a predominant strong stacking mode of interaction. Thermodynamic parameters suggest that the binding process is spontaneous and enthalpy-driven. These findings demonstrate the potential of KAE to selectively target and stabilize HRAS1 IM DNA, suggesting a promising strategy for transcriptional regulation and anticancer drug design. Furthermore, KAE's pronounced excited-state intramolecular proton transfer fluorescence properties may serve as innovative tools for detecting and quantifying HRAS1 IM DNA in tumor cells, with potential applications in theranostics.
Structural Diversity and Mechanistic Insights on Preferential Interaction of Small Molecule Ligands with i-Motif DNA Structures: Unlocking New Blueprint for Drug Discovery Sagar Bag, Souvik Ghosal, Mangal Deep Burman, Atanu Manna, Sudipta Bhowmik Chemistryselect, 2025 The cytosine‐rich i‐Motif (IM) is a four‐stranded DNA structure that exemplifies the remarkable structural flexibility of nucleic acids. Stabilized under mildly acidic conditions, IMs are typically found within gene promoters and telomeres, where they are believed to play roles in regulating gene expression and cellular proliferation. The interaction between small molecules and IM DNA holds significant promise for drug discovery and therapeutic development, particularly in targeting diseases such as cancer. These interactions can help identify novel drug targets and enable precision drug delivery strategies. Beyond their therapeutic potential, IMs possess unique structural properties—such as pH‐responsiveness and conformational changes upon ligand binding—that makes them highly suitable for use in biosensors. These features enable the sensitive and specific detection of target molecules, supporting a wide range of biomedical applications including disease diagnostics and theranostics. This review explores the structural characteristics of IMs, their biological relevance in drug development and delivery, as well as the mechanisms underlying their interactions with small molecules. Additionally, it discusses how the pH‐sensitive nature of IM‐DNA can be harnessed to design advanced biosensors and next‐generation drug delivery systems.
Glycation of Proteins and Its End Products: From Initiation to Natural Product-Based Therapeutic Preventions Mangal Deep Burman, Sagar Bag, Souvik Ghosal, Sudipta Bhowmik ACS Pharmacology and Translational Science, 2025 Diabetes is a chronic metabolic disorder characterized by elevated blood glucose levels, which lead to the glycation of proteins and the formation of advanced glycation end products (AGEs). These AGEs contribute to oxidative stress, inflammation, and the development of complications such as cardiovascular disease, nephropathy, and anemia, significantly increasing mortality rates among diabetic patients. This Review focuses on the role of glycation inhibitors as a potential strategy to prevent AGE-related pathologies. While synthetic glycation inhibitors have shown promise, their adverse effects highlight the need for safer alternatives. We specifically explore a range of natural compounds-flavonoids, curcuminoids, terpenes, stilbenes, lignans, and coumarins-that have demonstrated significant antiglycating properties. The mechanisms through which these natural products inhibit glycation, including antioxidant activity, metal ion chelation, and direct interference with the glycation process, are discussed in detail. This review underscores the potential of natural products as effective and safer glycation inhibitors, offering a promising avenue for the development of therapeutic strategies against diabetes and AGE-related disorders.
Microplastics-Induced Binding and Structural Changes in the Milk Proteins: α-Lactalbumin and β-Lactoglobulin S Ghosal, S Bag, MD Burman, S Bhowmik 2026
Exploring The Biophysical Interactions And Structural Insights Between Dietary Plant Flavonoids And Various Non Canonical Nucleic Acid Structures S Bag University of Calcutta , 2026 2026
Selective Stabilization of HRAS2 i-Motif DNA by TMPyP4: A Multimodal Biophysical and Thermodynamic Investigation S Bag, S Ghosal, MD Burman, E Chorell, S Bhowmik bioRxiv, 2026.04. 08.717182 , 2026 2026
Synthesis of tris-indolylmethanealkaloids by harnessing the nucleophilic reactivity of Indole-BX and studying their interactions with hemoglobin S Das, MD Burman, S Bag, R Soren, B Roy, S Bhowmik, RK Nandi New Journal of Chemistry 50 (1), 98-108 , 2026 2026
Impact of polystyrene microplastics on human alternative DNA structures S Bag, S Ghosal, S Bhowmik ChemistrySelect 11 (4), e02999 , 2026 2026
Smart drug in cancer treatment: Design, synthesis and biophysical characterization of uracil-containing cyclic hypervalent iodine (Uracil-BX) reagent with G-quadruplex DNA … S Das, S Bag, MA Sk, RK Nandi, S Bhowmik Bioorganic Chemistry, 109021 , 2025 2025 Citations: 1
Naphthalene Diimide‐Based Soft Materials Exhibiting High‐Performance, Tunable Electrical Properties Through Side‐Chain Engineering and Strong Binding Interactions with Human … SS Ahamed, N Khatun, MD Burman, S Bag, R Chakraborty, B Panda, ... Small 21 (33), 2504759 , 2025 2025 Citations: 2
Modulation of the HRAS1 I-motif DNA Promoter Region by Dietary Plant Flavonoid Kaempferol S Bag, S Ghosal, MD Burman, M Mukherjee, G Pramanik, S Bhowmik ACS omega 10 (29), 31381-31392 , 2025 2025
Artificial Intelligence in Cellular and Biomolecular Spectroscopy: A New Horizon S Bag, A Manna, S Bhowmik Artificial Intelligence (AI) in Cell and Genetic Engineering, 59-72 , 2025 2025
Structural Diversity and Mechanistic Insights on Preferential Interaction of Small Molecule Ligands with i‐Motif DNA Structures: Unlocking New Blueprint for Drug Discovery S Bag, S Ghosal, MD Burman, A Manna, S Bhowmik ChemistrySelect 10 (24), e01985 , 2025 2025 Citations: 3
Nickel‐Catalyzed Regioselective Access to Dibenzo [b, e] Azepinones: Mechanistic Study, Docking, and Biophysical Exploration of Binding Interactions with Human Hemoglobin SS Ahamed, US Mandal, S Bag, MD Burman, R Lo, D Manna, S Bhowmik, ... Chemistry–An Asian Journal, e00030 , 2025 2025 Citations: 2
Breaking barriers: A new phytomedicine based treatment approach for targeted unrevealed non-canonical DNA structures in tuberculosis bacteria S Bhowmik, T Shroff, S Bag, P Kadam, N Mistry bioRxiv, 2025.04. 08.647720 , 2025 2025
Exploring i-Motif DNA binding with benzothiazolino Coumarins: Synthesis, Screening, and spectroscopic insights S Bag, K Chand, MD Burman, S Vertueux, E Chorell, S Bhowmik Bioorganic chemistry 156, 108227 , 2025 2025 Citations: 3
Microplastics can alter structural configurations of human non-canonical G-quadruplex DNA S Bag, S Ghosal, S Bhowmik Environmental Toxicology and Pharmacology 114, 104626 , 2025 2025 Citations: 7
Glycation of proteins and its end products: from initiation to natural product-based therapeutic preventions MD Burman, S Bag, S Ghosal, S Bhowmik ACS Pharmacology & Translational Science 8 (3), 636-653 , 2025 2025 Citations: 12
Uracil-BX: A new class of cyclic hypervalent iodine reagents for unraveling approach towards umpolung functionalization and VEGF G-quadruplex DNA identification S Das, S Bag, MA Sk, P Majumdar, UK Das, S Bhowmik, RK Nandi ChemRxiv 2025 (0130) , 2025 2025 Citations: 3
Poly (vinyl chloride) microplastics induce structural and functional alterations in myoglobin S Ghosal, S Bag, S Bhowmik RSC advances 15 (34), 27576-27585 , 2025 2025 Citations: 2
Understanding the impact of the molecular crowding environment on the glyoxal-mediated glycation of hemoglobin MD Burman, S Bag, S Ghosal, S Bhowmik Physical Chemistry Chemical Physics 27 (22), 11821-11829 , 2025 2025
Decoding the Potential of HRAS2 i‐Motif DNA Promoter to Become a Pinpoint Target by Phytomedicine Naringenin S Bag, S Ghosal, S Bhowmik ChemistrySelect 10 (1), e202404775 , 2025 2025 Citations: 4
Deciphering Preferential Binding Interaction of Synthetic Pyrido [2, 3‐c] Carbazole Alkaloid Derivative (PCAD) with Pu24T G‐quadruplex DNA P Pal, S Bag, MD Burman, RK Nandi, S Bhowmik ChemistrySelect 9 (28), e202402561 , 2024 2024 Citations: 2
MOST CITED SCHOLAR PUBLICATIONS
Tea and its phytochemicals: Hidden health benefits & modulation of signaling cascade by phytochemicals S Bag, A Mondal, A Majumder, A Banik Food Chemistry 371, 131098 , 2022 2022 Citations: 196
Flavonoid mediated selective cross-talk between plants and beneficial soil microbiome S Bag, A Mondal, A Majumder, SK Mondal, A Banik Phytochemistry Reviews 21 (5), 1739-1760 , 2022 2022 Citations: 149
Exploring tea (Camellia sinensis) microbiome: Insights into the functional characteristics and their impact on tea growth promotion S Bag, A Mondal, A Banik Microbiological Research 254, 126890 , 2022 2022 Citations: 101
Structural insights and shedding light on preferential interactions of dietary flavonoids with G-quadruplex DNA structures: A new horizon S Bag, MD Burman, S Bhowmik Heliyon 9 (3) , 2023 2023 Citations: 31
Insights into the binding interactions between microplastics and human α-synuclein protein by multispectroscopic investigations and amyloidogenic oligomer formation S Ghosal, S Bag, S Bhowmik The Journal of Physical Chemistry Letters 15 (25), 6560-6567 , 2024 2024 Citations: 24
Exposure to polyethylene microplastics exacerbate inflammatory bowel disease tightly associated with intestinal gut microflora S Ghosal, S Bag, SR Rao, S Bhowmik RSC advances 14 (35), 25130-25148 , 2024 2024 Citations: 24
Unravelling the drug encapsulation ability of functional DNA origami nanostructures: current understanding and future prospects on targeted drug delivery S Ghosal, S Bag, S Bhowmik Polymers 15 (8), 1850 , 2023 2023 Citations: 23
Virtual screening and docking analysis of novel ligands for selective enhancement of tea (Camellia sinensis) flavonoids A Majumder, SK Mondal, S Mukhoty, S Bag, A Mondal, Y Begum, ... Food chemistry: X 13, 100212 , 2022 2022 Citations: 19
Quercetin exhibits preferential binding interaction by selectively targeting HRAS1 I-Motif DNA-forming promoter sequences S Bag, S Ghosal, M Mukherjee, G Pramanik, S Bhowmik Langmuir 40 (19), 10157-10170 , 2024 2024 Citations: 17
Uncovering the contrasting binding behavior of plant flavonoids fisetin and morin having subsidiary hydroxyl groups (− OH) with HRAS1 and HRAS2 i-Motif DNA structures: decoding … S Bag, S Ghosal, S Karmakar, G Pramanik, S Bhowmik ACS omega 8 (33), 30315-30329 , 2023 2023 Citations: 17
Multispectroscopic investigations of the binding interaction between polyethylene microplastics and human hemoglobin S Ghosal, S Bag, MD Burman, S Bhowmik The Journal of Physical Chemistry Letters 14 (46), 10328-10332 , 2023 2023 Citations: 16
Fluorescence spectroscopy: A useful method to explore the interactions of small molecule ligands with DNA structures S Bag, S Bhowmik Reverse Engineering of Regulatory Networks, 33-49 , 2023 2023 Citations: 14
Exploring the structural importance of the C3═ C4 double bond in plant alkaloids harmine and harmaline on their binding interactions with hemoglobin MD Burman, S Bag, S Ghosal, S Karmakar, G Pramanik, RK Chinnadurai, ... ACS omega 8 (40), 37054-37064 , 2023 2023 Citations: 13
Glycation of proteins and its end products: from initiation to natural product-based therapeutic preventions MD Burman, S Bag, S Ghosal, S Bhowmik ACS Pharmacology & Translational Science 8 (3), 636-653 , 2025 2025 Citations: 12
Revealing the improved binding interaction of plant alkaloid harmaline with human hemoglobin in molecular crowding condition MD Burman, S Bag, S Ghosal, M Mukherjee, G Pramanik, S Bhowmik ACS omega 9 (19), 21668-21679 , 2024 2024 Citations: 8
Microplastics can alter structural configurations of human non-canonical G-quadruplex DNA S Bag, S Ghosal, S Bhowmik Environmental Toxicology and Pharmacology 114, 104626 , 2025 2025 Citations: 7
Decoding the Potential of HRAS2 i‐Motif DNA Promoter to Become a Pinpoint Target by Phytomedicine Naringenin S Bag, S Ghosal, S Bhowmik ChemistrySelect 10 (1), e202404775 , 2025 2025 Citations: 4
Investigating the preferential interaction between imatinib mesylate and VEGF G-quadruplex DNA as therapeutic strategies for cancer treatment: Biophysical and molecular … S Ghosal, S Bag, RK Chinnadurai, M Mukherjee, G Pramanik, S Bhowmik Computers in Biology and Medicine 177, 108683 , 2024 2024 Citations: 4
Structural Diversity and Mechanistic Insights on Preferential Interaction of Small Molecule Ligands with i‐Motif DNA Structures: Unlocking New Blueprint for Drug Discovery S Bag, S Ghosal, MD Burman, A Manna, S Bhowmik ChemistrySelect 10 (24), e01985 , 2025 2025 Citations: 3
Exploring i-Motif DNA binding with benzothiazolino Coumarins: Synthesis, Screening, and spectroscopic insights S Bag, K Chand, MD Burman, S Vertueux, E Chorell, S Bhowmik Bioorganic chemistry 156, 108227 , 2025 2025 Citations: 3
RESEARCH OUTPUTS (PATENTS, SOFTWARE, PUBLICATIONS, PRODUCTS)
Research Publications in Highly reputed peer-reviewed Journals.
Industry, Institute, or Organisation Collaboration
1. The Foundation for Medical Research
Dr. Kantilal J Sheth Memorial Building, 84-A, Dr RG Thadani Marg, Siddharth Nagar, Worli, Mumbai, Maharashtra 400018
2. Mahatma Gandhi Medical Advanced Research Institute (MGMARI)
Sri Balaji Vidyapeeth (Deemed to be University), SBV Campus Pillaiyarkuppam Pondicherry - 607 402. India
3. UGC-DAE Consortium for Scientific Research
Kolkata Centre
Sector III, LB-8, Bidhan Nagar, Kolkata 700 106.
UGC-DAE Consortium for Scientific Research is an autonomous institute of the University Grants Commission (UGC), India
4. Department of Chemistry, Jadavpur University, Kolkata 700 032, INDIA.
STARTUP
I-motif (IM) DNA structures represents among the most significant non-canonical nucleic acid configurations. IM forming DNA sequences are found in an array of vital genomic locations and are particularly frequent in the promoter islands of various oncogenes. Thus, IM DNA is a crucial candidate for anticancer medicines, therefore binding interactions between IM DNA and small molecular ligands such as flavonoids are critically important. Flavonoids therefore emerged as a suitable natural product-oriented antagonist for targeting IM DNA. The innovative spectroscopic as well as mechanical features of flavonoids and its specific affinity for selective IM may be useful for therapeutic applications and provide crucial insights for the design of compounds with remarkable medicinal properties. Flavonoids' pioneering unique features might be used in theranostics applications and drug development. The results we have found are very promising and for future drug designing flavonoid may be used as a base molecule by some modifications/appropriate tuning in their structure. Quercetin is also a very promising molecule that may be used in ligand-based drug development, which begins with a single ligand known to be powerful against a target. Effectiveness and other critical qualities are enhanced by developing relevant analogues based on structure-activity relationships.
SOCIAL, ECONOMIC, or ACADEMIC BENEFITS
1. Honorary Scientific member of American Chemical Society (ACS), USA, 2024 [ACS Membership ID:-33476729].
2. Honorary Scientific member of Royal Society of Chemistry (RSC), UK, 2024 [RSC Membership ID:-767611].
3. Prestigious Fellow of Scholars Academic and Scientific Society (FSASS), SAS Society, An International Society for Academic & Scientific Integration, with Membership ID-SAS/FSASS/748/2024; 2nd September, 2024; .
4. Dignitary Royal Fellow awarded “FRIOASD” by International Organization for Academic and Scientific Development.
5. Academic Peer Reviewer in the Scientific Reports (Nature), Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Computers in Biology and Medicine Journal, Elsevier, ScienceDirect (Impact ISSN: 0010-4825) [Reviewing 11 Research Articles].
6. Associate Editor in Frontiers in Biophysics.