Browsing by Author "Veeranagaiah, N.S."

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Click chemistry assisted synthesis of imidazo[1,2-a]pyrimidine-1,2,3-triazole hybrids as promising antitubercular agents: Design, characterization, in-vitro biological evaluation, molecular docking, DFT and in-silico ADME studies
(Elsevier B.V., 2025) P, D.; Naik, S.; Veeranagaiah, N.S.; Udayakumar, U.
In this work, the molecular hybridization approach was employed to design a series of imidazo[1,2-a]pyrimidine -1,2,3-triazole derivatives (P1-P18), and the designed hybrid molecules were synthesized using a click chemistry protocol. The structure of one of the final compounds P10, was validated by single-crystal X-ray diffraction investigation. Among these 18 compounds, P3, P13, and P15 demonstrated encouraging antitubercular action against the M. tuberculosis H37Rv strain with minimum inhibitory concentrations (MIC) of 12.05 and 11.95 µM of (P3 and P13) or 6.75 µM (P15). In addition, at various concentrations, the target compounds demonstrated strong antifungal activity against P. anomala and A. flavus and antibacterial activity against S. aureus and Escherichia coli. The potent anti-TB agents (P3, P13, and P15) are non-toxic in the toxicity test performed using VERO cell lines. Furthermore, In-silico ADME, molecular docking (with InhA and CYP121), and DFT analysis data revealed that the active compounds have substantial potential as candidates for the development of novel antitubercular medicines. © 2025 Elsevier B.V.
Hydrazineyl-linked imidazole[1,2-a]pyrimidine-thiazole hybrids: design, synthesis, and in vitro biological evaluation studies
(Royal Society of Chemistry, 2025) Dinesha, P.; Naik, S.; Udayakumar, U.; Revanasiddappa, B.C.; Ranjan, V.; Veeranagaiah, N.S.
This research work details the use of a molecular hybridization technique to create a library of four series of hydrazineyl-linked imidazo[1,2-a]pyrimidine-thiazole derivatives. The structure of one of the final products, K2, was validated using single-crystal X-ray diffraction. Twenty-six novel hybrid molecules (K1-K26) were synthesized and tested for activity against the mycobacterium tuberculosis H37Rv strain. Three compounds (K1, K2, and K3) demonstrated significant inhibitory efficacy, with a MIC value of 1.6 ?g mL?1. The target compounds also showed significant antibacterial activity against four bacterial strains, namely S. aureus, E. coli, B. subtilis, and P. aeruginosa. In cytotoxicity studies using VERO cells, the potent anti-TB compounds (K1, K2, and K3) showed non-toxic profiles. Furthermore, in silico ADME assessment results, molecular docking (against InhA and CYP121), and DFT studies revealed the active compounds' significant potential as scaffolds for novel antitubercular medicines. © 2025 The Royal Society of Chemistry.
Imidazo[1,2-a]pyrimidine-Linked Pyridine, Pyrazine, and Pyrimidine Derivatives: Design, Synthesis, and Antitubercular Activity Evaluation
(John Wiley and Sons Inc, 2025) Puttachari, D.; Naik, S.; Veeranagaiah, N.S.; Udayakumar, U.
In this study, a molecular hybridization strategy was used to design a series of imidazo[1,2-a]pyrimidine-linked pyridine, pyrazine, and pyrimidine derivatives (T1–T20) and the hybrid compounds were synthesized via a multistep procedure. The structure of one of the target compounds T11, was studied using single-crystal X-ray diffraction investigation. These final molecules were thoroughly tested against Mycobacterium tuberculosis H37Rv strain, and compound T11 showed the best activity with MIC of 0.8 µg/mL, while compounds T5 and T18 showed promising inhibition activity (MIC 3.12 µg/mL). The target compounds were further tested for antibacterial activity against Staphylococcus aureus and Escherichia coli, finding the MIC and MBC values. Many of the compounds exhibited notable antibacterial properties. The promising anti-TB drugs (T5, T11, and T18) were shown to be nontoxic in toxicity studies on VERO cell lines. The combined results from in silico ADME, molecular docking, and DFT studies indicate that the active compounds possess strong potential as antitubercular candidates. © 2025 Wiley-VCH GmbH.
ortho-Halogen functionalized N-squaraines: structure–property relationship and dual-mode colorimetric and fluorometric sulfide ion detection
(Royal Society of Chemistry, 2025) Fernandes, P.P.; Shenoy, A.M.; Grover, V.; Veeranagaiah, N.S.; Lakshmi, V.
Symmetric ortho-halogen derivatives of anilinium N-squaraines were synthesized and characterized using 1H-NMR, mass, FT-IR, and single-crystal X-ray diffraction techniques. The effect of halogen substituents (–F, –Cl, –Br, –I) on the optoelectronic and electrochemical properties of N-squaraines has been thoroughly investigated. Additionally, the theoretical calculations demonstrated that the ortho functionalization slightly lowers the HOMO–LUMO energy band gap, which aligns with the optical band gap. Moreover, the solid-state photophysical characterization revealed that the photo-excited state remains a singlet, even in the presence of heavy atoms like bromine and iodine. The solid-state fluorescence emission was also significantly higher than in the solution state, with the quantum yields soaring up to 24%. Further, the two acidic binding sites in the synthesized compounds 2–5 were evaluated for anion sensing. The o-halo-derivatives act as selective dual-mode colorimetric and “Turn-On” fluorometric chemosensors for sulfide anions, with the solution changing from colorless to yellow and a four-fold enhanced emission intensity. Furthermore, adding acid makes the solution turn colorless again, as investigated in detail using the o-chloro-derivative. The chemosensor displayed good reversibility for up to seven cycles and demonstrated applications in molecular logic gates. This journal is © The Royal Society of Chemistry, 2025