Synthesis of 1,2,3-Triazole and Isoxazole Derivatives of [1,2,4]Triazolo[3,4-b][1,3,4]thiadiazine as Potent EGFR Targeting Antilung Cancer Agents Arvapalli Kiran Kumar, T. Madhukar Reddy, Sridhar Kavela, Sirassu Narsimha, Kavitha Siddoju Chemistry and Biodiversity, 2026 Imidazole‐1,2,4triazolo[3,4‐b][1,3,4]thiadiazines associated 1,2,3‐triazole and isoxazole hybrids were designed and synthesized using a pharmacophore‐hybridization approach that incorporates physiologically active scaffolds. In vitro anticancer activity of the synthesized compounds was screened against two lung cancer cell lines, A‐549 and NCI‐H460, and results revealed that compounds 6d and 6h had substantial efficacy compared to the standard erlotinib. Furthermore, compound 6h (IC 50 = 0.61 ± 0.12 µM) exhibited greater effectiveness as compared to the conventional Erlotinib (IC 50 = 0.64 ± 0.23 µM) in vitro, as shown by EGFR inhibitory tests, whereas compound 6d (IC 50 = 0.65 ± 0.09 µM) indicated notable EGFR inhibitory action. To confirm the activity findings, five potent compounds underwent in silico molecular docking studies, with all compounds demonstrating superior binding energies relative to the standard.
Synthesis and antimicrobial activity of sulfonyl-imidazole linked fused isoxazolo[3,4-b][1,2,3]triazolo[4,5-d]pyridines:PEG-400 mediated one-pot reaction under ultrasonic irradiation Karukuri Premalatha, Ravikumar Kapavarapu, Sridhar Kavela, Sirassu Narsimha Frontiers in Chemistry, 2026 Introduction The rapid emergence of methicillin-resistant and vancomycin-resistant Staphylococcus aureus (MRSA and VRSA) represents a major global health challenge, necessitating the development of new antibacterial scaffolds with improved efficacy and safety. Methods In this study, a novel series of sulfonyl-imidazole-linked fused isoxazolo[3,4-b][1,2,3]triazolo[4,5-d]pyridine derivatives (6a–6o) was synthesized using a PEG-400-mediated, ultrasound-assisted one-pot Cu(I)-catalysed strategy under environmentally benign conditions. The synthesized compounds were evaluated for antibacterial activity against MSSA, MRSA, and VRSA strains, along with antibiofilm activity, hemolytic potential using mouse erythrocytes, and cytotoxicity in RAW 264.7, THP-1, and BoMac cells. Immunomodulatory effects were assessed through cytokine induction studies. Results Several derivatives exhibited potent antibacterial activity, with compound 6k emerging as the most active candidate, displaying MIC values of 1.56–3.12 μg/mL and outperforming the reference drug dicloxacillin. Selected compounds also showed significant antibiofilm activity against resistant S. aureus strains. Hemolysis and cytotoxicity assays demonstrated minimal toxicity, indicating good biocompatibility. Immunomodulatory analysis revealed moderate cytokine induction, suggesting a controlled immune response. Discussion Overall, compound 6k was identified as a promising lead with potent antibacterial, antibiofilm, and immunomodulatory properties, combined with a favourable safety profile, warranting further preclinical development against drug-resistant S. aureus infections.
Adjuvant activity of a small molecule TLR4 agonist discovered via structure-based virtual screening Mohammad Kadivella, Vivek P. Varma, Jusail CP, Sridhar Kavela, Sarwar Azam, Syed M. Faisal Communications Biology, 2025 Monophosphoryl lipid A (MPLA), a TLR4 agonist, is a clinically approved vaccine adjuvant, but its complex structure and occasional toxicity limit broader use. Synthetic small-molecule TLR4 agonists offer advantages such as ease of synthesis, lower cost, and reduced toxicity. In this study, we conducted structure-based virtual screening of the ZINC database to identify novel TLR4-targeting small molecules across human, murine, and bovine species. Three lead compounds-NSF-418, NSF-501, and NSF-951-were selected based on favorable binding interactions and subjected to in vitro and in vivo evaluation. NSF-951 emerged as a potent TLR4 agonist, inducing strong proinflammatory cytokine responses (IL-6, TNF-α), upregulating CD80 and CD86 expression, and promoting macrophage maturation. Conversely, NSF-418 and NSF-501 acted as antagonists by suppressing MPLA-induced responses. In murine immunization studies, NSF-951, alone or with Alum (AF007), significantly enhanced OVA-specific antibody and T-cell responses without observable toxicity. These findings suggest that NSF-951 is a promising, cost-effective TLR4 agonist with strong immunostimulatory and adjuvant potential. Further studies are warranted to assess its performance with other antigens and adjuvant combinations, supporting its development as a next-generation adjuvant for veterinary and human vaccines.
Broad-spectrum antimicrobial activity and in vivo efficacy of SK1260 against bacterial pathogens Sridhar Kavela, Swetha Kakkerla, Murali Krishna Thupurani Frontiers in Microbiology, 2025 IntroductionAntimicrobial resistance (AMR) is a growing global health concern, necessitating the development of novel therapeutic agents. Antimicrobial peptides (AMPs) have emerged as promising candidates due to their broad-spectrum activity and lower resistance potential. SK1260 is a newly developed AMP evaluated for its efficacy against Gram-positive and Gram-negative pathogens, including multidrug-resistant strains.MethodsThe antimicrobial activity of SK1260 was assessed through minimum inhibitory concentration (MIC) assays against clinical and reference strains of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Time-kill kinetics were performed to evaluate bactericidal activity over time. In vivo efficacy was determined using murine infection models, where bacterial burden, tissue pathology, and survival rates were assessed following peptide administration.ResultsSK1260 exhibited potent antibacterial activity, with MIC values ranging from 3.13 to 12.5 µg/mL. Time-kill studies demonstrated dose- and time-dependent bactericidal effects, achieving complete bacterial clearance at concentrations ≥1× MIC, comparable to ciprofloxacin. In vivo studies revealed significant reductions in bacterial loads in vital organs, reduced histopathological damage, and improved survival in treated mice. Peptide treatment restored normal tissue architecture and showed efficacy equivalent to standard antibiotic therapy.DiscussionThe study establishes SK1260 as a promising broad-spectrum antimicrobial agent with efficacy against drug-resistant pathogens. Its ability to reduce bacterial burden and protect tissue integrity in vivo highlights its therapeutic potential. Further preclinical development and clinical trials are warranted to explore SK1260 as a viable alternative in the fight against AMR.
Organocatalytic[3 + 2]Cycloaddition: Synthesis of Quinazoline Containing Sulfonyl 1,2,3-Triazoles as Potent EGFR Targeting Anti-Breast Cancer Agents Venkat Reddy Dodlapati, E. Ramya Sucharitha, Rambabu Palabindela, Ravikumar Kapavarapu, Sridhar Kavela, Sirassu Narsimha Journal of Heterocyclic Chemistry, 2024 A general strategy was developed for the synthesis of new fully decorated 1,2,3‐triazoles (4a–4m and 5a–5g) containing quinazolines from 1‐(4‐nitrophenyl)‐2‐(quinazolin‐8‐ylsulfonyl) ethan‐1‐one and several azides using Ramachary organocatalytic azide‐ketone cycloaddition method. This reaction is reported for the synthesis of fully substituted sulfonyl‐1,2,3‐triazolyl quinazolins at a temperature of 100°C and the yields of the products produced are satisfactory to excellent. In vitro anticancer activity of all these derivatives demonstrated that six compounds, 4d, 4f, 4i, 4j, 5d, and 5e, were effective against two human breast cancer cell lines, MCF‐7 and MDA‐MB‐231. Compounds 4f, 4j, and 5d had more action against both cell lines than Erlotinib. Later, the findings of inhibitory assays of potent compounds 4d, 4f, 4i, 4j, 5d, and 5e against the tyrosine kinase EGFR revealed that compound 5d proved more potent than the reference erlotinib, while 4f and 4j had comparable efficacy. In silico molecular docking studies were also performed on six strong medicines to identify interactions with the EGFR receptor, and the energy estimations were shown to be comparable with the observed IC50 values. Ultimately, using SWISS/ADME and pkCSM, the in silico pharmacokinetic profile of potent compounds 4d, 4f, 4i, 4j, 5d, and 5e was predicted. All of the compounds precisely followed the principles established by Lipinski, Veber, Egan, and Muegge.
Leptospira Lipid A Is a Potent Adjuvant That Induces Sterilizing Immunity against Leptospirosis Vivek P. Varma, Mohammad Kadivella, Sridhar Kavela, Syed M. Faisal Vaccines, 2023 Leptospirosis is a globally significant zoonotic disease. The current inactivated vaccine offers protection against specific serovars but does not provide complete immunity. Various surface antigens, such as Leptospira immunoglobulin-like proteins (LigA and LigB), have been identified as potential subunit vaccine candidates. However, these antigens require potent adjuvants for effectiveness. Bacterial lipopolysaccharides (LPSs), including lipid A, are a well-known immunostimulant, and clinical adjuvants often contain monophosphoryl lipid A (MPLA). Being less endotoxic, we investigated the adjuvant properties of lipid A isolated from L. interrogans serovar Pomona (PLA) in activating innate immunity and enhancing antigen-specific adaptive immune responses. PLA activated macrophages to a similar degree as MPLA, albeit at a higher dose, suggesting that it is less potent in stimulation than MPLA. Mice immunized with a variable portion of LigA (LAV) combined with alum and PLA (LAV-alum-PLA) exhibited significantly higher levels of LAV-specific humoral and cellular immune responses compared to alum alone but similar to those induced by alum-MPLA. The adjuvant activity of PLA resembles that of MPLA and is primarily achieved through the increased recruitment, activation, and uptake of antigens by innate immune cells. Furthermore, like MPLA, PLA formulation establishes a long-lasting memory response. Notably, PLA demonstrated superior potency than MPLA formulation and provided sterilizing immunity against the leptospirosis in a hamster model. Overall, our study sheds light on the adjuvant properties of Leptospira lipid A and offers promising avenues for developing LPS-based vaccines against this devastating zoonotic disease.
LigA formulated in AS04 or Montanide ISA720VG induced superior immune response compared to alum, which correlated to protective efficacy in a hamster model of leptospirosis Vivek P. Varma, Mohammad Kadivella, Ajay Kumar, Sridhar Kavela, Syed M. Faisal Frontiers in Immunology, 2022 Leptospirosis is a zoonotic disease of global importance. The current vaccine provides serovar-specific and short-term immunity and does not prevent bacterial shedding in infected animals. Subunit vaccines based on surface proteins have shown to induce protection in an animal model. However, these proteins were tested with non-clinical adjuvants and induced low to moderate protective efficacy. We formulated a variable region of Leptospira immunoglobulin-like protein A (LAV) in clinical adjuvants, AS04 and Montanide ISA720VG, and then evaluated the immune response in mice and protective efficacy in a hamster model. Our results show that animals immunized with LAV-AS04 and LAV-Montanide ISA720VG (LAV-M) induced significantly higher levels of LAV-specific antibodies than LAV-Alum. While LAV-Alum induced Th2 response with the induction of IgG1 and IL-4, AS04 and LAV-M induced a mixed Th1/Th2 response with significant levels of both IgG1/IL-4 and IgG2c/IFN-γ. Both LAV-AS04 and LAV-M induced the generation of a significantly higher number of cytotoxic T cells (CTLs). The immune response in LAV-AS04- and LAV-M-immunized animals was maintained for a long period (>180 days) with the generation of a significant level of B- and T-cell memory. The strong immune response by both vaccines correlated to enhanced recruitment and activation of innate immune cells particularly DCs at draining lymph nodes and the formation of germinal centers (GCs). Furthermore, the immune response generated in mice correlated to protective efficacy in the hamster model of leptospirosis. These results indicate that LAV-AS04 and LAV-M are promising vaccines and can be further evaluated in clinical trials.
PNUTS functions as a proto-oncogene by sequestering PTEN Sridhar Kavela, Swapnil R. Shinde, Raman Ratheesh, Kotapalli Viswakalyan, Murali D. Bashyam, Swarnalata Gowrishankar, Mohana Vamsy, Sujit Pattnaik, Subramanyeshwar Rao, Regulagadda A. Sastry, Mukta Srinivasulu, Junjie Chen, Subbareddy Maddika Cancer Research, 2013
WWP2 is an E3 ubiquitin ligase for PTEN Subbareddy Maddika, Sridhar Kavela, Neelam Rani, Vivek Reddy Palicharla, Jenny L. Pokorny, Jann N. Sarkaria, Junjie Chen Nature Cell Biology, 2011
RECENT SCHOLAR PUBLICATIONS
Synthesis of 1, 2, 3-Triazole and Isoxazole Derivatives of [1, 2, 4] Triazolo [3, 4-b][1, 3, 4] thiadiazine as Potent EGFR Targeting Antilung Cancer Agents AK Kumar, TM Reddy, S Kavela, S Narsimha, K Siddoju Chemistry & biodiversity 23 (4), e02795 , 2026 2026
Synthesis and anti-lung cancer evaluation of fused pyrazolo [3, 4-b] pyridine linked isoxazoles and 1, 2, 3-triazoles: PEG-400 mediated one-pot reaction under microwave irradiation G Jyothi, R Palabindela, R Kapavarapu, S Kavela, S Narsimha Bioorganic Chemistry, 109711 , 2026 2026
Synthesis and antimicrobial activity of Sulfonyl-imidazole linked fused isoxazolo [3, 4-b][1, 2, 3] triazolo [4, 5-d] pyridines: PEG-400 mediated one-pot reaction under … K Premalatha, R Kapavarapu, S Kavela, S Narsimha Frontiers in Chemistry 14, 1784084 , 2026 2026
Evaluating the Efficacy of SK1217 in Attenuating Pristane-Induced Lupus in Mice S Kakkerla, S Kavela, S Chintalapani Frontiers in Lupus 4, 1466123 , 2026 2026
Adjuvant activity of a small molecule TLR4 agonist discovered via structure-based virtual screening M Kadivella, VP Varma, J Cp, S Kavela, S Azam, SM Faisal Communications Biology 8 (1), 1382 , 2025 2025 Citations: 6
Characterization of novel peptides with antimicrobial and immunomodulatory potential S Kakkerla, S Kavela, M Kadivella, MK Thupurani, S Chintalapani Discover Medicine 2 (1), 252 , 2025 2025 Citations: 6
Broad-spectrum antimicrobial activity and in vivo efficacy of SK1260 against bacterial pathogens S Kavela, S Kakkerla, MK Thupurani Frontiers in Microbiology 16, 1553693 , 2025 2025 Citations: 8
Proteomic Analysis of Staphylococcus aureus Under SK1260 Treatment Highlights Membrane Stress Response and Virulence Attenuation S Kavela, MK Thupurani Journal of Molecular Science 35 (3), 995-1004 , 2025 2025
SK1281, a Novel Peptide-Based IDO1 Inhibitor, Suppresses Tryptophan Metabolism and Induces Apoptosis in Colorectal Cancer Cells S Kakkerla, S Kavela, S Chintalapani Journal of Molecular Science 35 (3), 1005-1012 , 2025 2025
New quinazoline-[1, 2, 4] triazolo [3, 4-b][1, 3, 4] thiadiazines as inhibitors of EGFR: synthesis, anti-breast cancer evaluation and in silico studies MD Bandgar, S Peddapelli, R Kapavarapu, J Boruwa, S Kavela, ... RSC Medicinal Chemistry 16 (9), 4154-4169 , 2025 2025 Citations: 4
Organocatalytic [3+ 2] Cycloaddition: synthesis of quinazoline containing sulfonyl 1, 2, 3‐Triazoles as potent EGFR targeting Anti‐Breast cancer agents VR Dodlapati, E Ramya Sucharitha, R Palabindela, R Kapavarapu, ... Journal of Heterocyclic Chemistry 61 (11), 1762-1776 , 2024 2024 Citations: 13
Leptospira Lipid A Is a Potent Adjuvant That Induces Sterilizing Immunity against Leptospirosis VP Varma, M Kadivella, S Kavela, SM Faisal Vaccines 11 (12), 1824 , 2023 2023 Citations: 5
Use of an Integrated Multi-Omics Approach To Identify Molecular Mechanisms and Critical Factors Involved in the Pathogenesis of Leptospira S Kavela, P Vyas, J Cp, SK Kushwaha, SS Majumdar, SM Faisal Microbiology Spectrum 11 (2), e03135-22 , 2023 2023 Citations: 13
LigA formulated in AS04 or Montanide ISA720VG induced superior immune response compared to alum, which correlated to protective efficacy in a hamster model of leptospirosis VP Varma, M Kadivella, A Kumar, S Kavela, SM Faisal Frontiers in Immunology 13, 985802 , 2022 2022 Citations: 13
Deciphering the Role of Leptospira Surface Protein LigA in Modulating the Host Innate Immune Response A Kumar, VP Varma, K Sridhar, M Abdullah, P Vyas, M Ashiq Thalappil, ... Frontiers in Immunology 12, 807775 , 2021 2021 Citations: 19
TOPK and PTEN participate in CHFR mediated mitotic checkpoint SR Shinde, NR Gangula, S Kavela, V Pandey, S Maddika Cellular signalling 25 (12), 2511-2517 , 2013 2013 Citations: 54
PTEN-lipid Binding Assay S Kavela, SR Shinde, S Maddika Bio-protocol 3 (16), e869-e869 , 2013 2013
Synthesis and evaluation of 3-amino/guanidine substituted phenyl oxazoles as a novel class of LSD1 inhibitors with anti-proliferative properties K Sridhar, K TulasiáKirla, G SingháDeora Organic & biomolecular chemistry 11 (19), 3103-3107 , 2013 2013 Citations: 62
PNUTS functions as a proto-oncogene by sequestering PTEN S Kavela, SR Shinde, R Ratheesh, K Viswakalyan, MD Bashyam, ... Cancer research 73 (1), 205-214 , 2013 2013 Citations: 68
WWP2 is an E3 ubiquitin ligase for PTEN S Maddika, S Kavela, N Rani, VR Palicharla, JL Pokorny, JN Sarkaria, ... Nature cell biology 13 (6), 728-733 , 2011 2011 Citations: 386
MOST CITED SCHOLAR PUBLICATIONS
WWP2 is an E3 ubiquitin ligase for PTEN S Maddika, S Kavela, N Rani, VR Palicharla, JL Pokorny, JN Sarkaria, ... Nature cell biology 13 (6), 728-733 , 2011 2011 Citations: 386
PNUTS functions as a proto-oncogene by sequestering PTEN S Kavela, SR Shinde, R Ratheesh, K Viswakalyan, MD Bashyam, ... Cancer research 73 (1), 205-214 , 2013 2013 Citations: 68
Synthesis and evaluation of 3-amino/guanidine substituted phenyl oxazoles as a novel class of LSD1 inhibitors with anti-proliferative properties K Sridhar, K TulasiáKirla, G SingháDeora Organic & biomolecular chemistry 11 (19), 3103-3107 , 2013 2013 Citations: 62
TOPK and PTEN participate in CHFR mediated mitotic checkpoint SR Shinde, NR Gangula, S Kavela, V Pandey, S Maddika Cellular signalling 25 (12), 2511-2517 , 2013 2013 Citations: 54
Deciphering the Role of Leptospira Surface Protein LigA in Modulating the Host Innate Immune Response A Kumar, VP Varma, K Sridhar, M Abdullah, P Vyas, M Ashiq Thalappil, ... Frontiers in Immunology 12, 807775 , 2021 2021 Citations: 19
Organocatalytic [3+ 2] Cycloaddition: synthesis of quinazoline containing sulfonyl 1, 2, 3‐Triazoles as potent EGFR targeting Anti‐Breast cancer agents VR Dodlapati, E Ramya Sucharitha, R Palabindela, R Kapavarapu, ... Journal of Heterocyclic Chemistry 61 (11), 1762-1776 , 2024 2024 Citations: 13
Use of an Integrated Multi-Omics Approach To Identify Molecular Mechanisms and Critical Factors Involved in the Pathogenesis of Leptospira S Kavela, P Vyas, J Cp, SK Kushwaha, SS Majumdar, SM Faisal Microbiology Spectrum 11 (2), e03135-22 , 2023 2023 Citations: 13
LigA formulated in AS04 or Montanide ISA720VG induced superior immune response compared to alum, which correlated to protective efficacy in a hamster model of leptospirosis VP Varma, M Kadivella, A Kumar, S Kavela, SM Faisal Frontiers in Immunology 13, 985802 , 2022 2022 Citations: 13
Broad-spectrum antimicrobial activity and in vivo efficacy of SK1260 against bacterial pathogens S Kavela, S Kakkerla, MK Thupurani Frontiers in Microbiology 16, 1553693 , 2025 2025 Citations: 8
Adjuvant activity of a small molecule TLR4 agonist discovered via structure-based virtual screening M Kadivella, VP Varma, J Cp, S Kavela, S Azam, SM Faisal Communications Biology 8 (1), 1382 , 2025 2025 Citations: 6
Characterization of novel peptides with antimicrobial and immunomodulatory potential S Kakkerla, S Kavela, M Kadivella, MK Thupurani, S Chintalapani Discover Medicine 2 (1), 252 , 2025 2025 Citations: 6
Leptospira Lipid A Is a Potent Adjuvant That Induces Sterilizing Immunity against Leptospirosis VP Varma, M Kadivella, S Kavela, SM Faisal Vaccines 11 (12), 1824 , 2023 2023 Citations: 5
New quinazoline-[1, 2, 4] triazolo [3, 4-b][1, 3, 4] thiadiazines as inhibitors of EGFR: synthesis, anti-breast cancer evaluation and in silico studies MD Bandgar, S Peddapelli, R Kapavarapu, J Boruwa, S Kavela, ... RSC Medicinal Chemistry 16 (9), 4154-4169 , 2025 2025 Citations: 4
Synthesis of 1, 2, 3-Triazole and Isoxazole Derivatives of [1, 2, 4] Triazolo [3, 4-b][1, 3, 4] thiadiazine as Potent EGFR Targeting Antilung Cancer Agents AK Kumar, TM Reddy, S Kavela, S Narsimha, K Siddoju Chemistry & biodiversity 23 (4), e02795 , 2026 2026
Synthesis and anti-lung cancer evaluation of fused pyrazolo [3, 4-b] pyridine linked isoxazoles and 1, 2, 3-triazoles: PEG-400 mediated one-pot reaction under microwave irradiation G Jyothi, R Palabindela, R Kapavarapu, S Kavela, S Narsimha Bioorganic Chemistry, 109711 , 2026 2026
Synthesis and antimicrobial activity of Sulfonyl-imidazole linked fused isoxazolo [3, 4-b][1, 2, 3] triazolo [4, 5-d] pyridines: PEG-400 mediated one-pot reaction under … K Premalatha, R Kapavarapu, S Kavela, S Narsimha Frontiers in Chemistry 14, 1784084 , 2026 2026
Evaluating the Efficacy of SK1217 in Attenuating Pristane-Induced Lupus in Mice S Kakkerla, S Kavela, S Chintalapani Frontiers in Lupus 4, 1466123 , 2026 2026
Proteomic Analysis of Staphylococcus aureus Under SK1260 Treatment Highlights Membrane Stress Response and Virulence Attenuation S Kavela, MK Thupurani Journal of Molecular Science 35 (3), 995-1004 , 2025 2025
SK1281, a Novel Peptide-Based IDO1 Inhibitor, Suppresses Tryptophan Metabolism and Induces Apoptosis in Colorectal Cancer Cells S Kakkerla, S Kavela, S Chintalapani Journal of Molecular Science 35 (3), 1005-1012 , 2025 2025
PTEN-lipid Binding Assay S Kavela, SR Shinde, S Maddika Bio-protocol 3 (16), e869-e869 , 2013 2013