INTERNATIONAL JOURNAL OF ACADEMIC EXCELLENCE AND RESEARCH (IJAER) e-ISSN: 3107-3913 ( Vol. 02 | No. 3 | July - September, 2026 )

Biosynthesized Silver Nanoparticles for Knoevenagel Condensation: A Comparative Study of Catalyzed and Catalyst-Free Conditions

Author: Prakash Chandra Dhabas, Ashok K. Kakodia, Kumud Tanwar, Swati Singh & Siddhi Jain

The present study explores a sustainable approach for the synthesis of silver nanoparticles (AgNPs) using Phyllanthus emblica fruit extract and their application as a heterogeneous catalyst for the Knoevenagel condensation of N-methylisatin and 5-methylisatin with rhodanine and 3-ethylrhodanine. The synthesized AgNPs exhibited characteristic nanoscale properties and good catalytic activity. The nanoparticles showed predominantly spherical morphology and a crystalline structure, while demonstrating efficient catalytic performance in aqueous conditions with good product yields. The catalyst was also recoverable and reusable, highlighting its potential as a green heterogeneous catalyst. Catalyst-free experiments under identical conditions are also important for determining the actual contribution of AgNPs to the reaction. Overall, the study demonstrates the potential of P. emblica-mediated AgNPs as a recoverable catalyst for the aqueous synthesis of isatin–rhodanine derivatives.

Dhabas, P., Kakodia, A., Tanwar, K., Singh, S. & Jain, S. (2026). Biosynthesized Silver Nanoparticles for Knoevenagel Condensation: A Comparative Study of Catalyzed and Catalyst-Free Conditions. International Journal of Academic Excellence and Research, 02(03), 61–74. https://doi.org/10.62823/IJAER/02.03.253

  1. Anastas, P. T., & Warner, J. C. (1998). Green chemistry: Theory and practice. Oxford University Press.
  2. Anastas, P. T., & Eghbali, N. (2010). Green chemistry: Principles and practice. Chemical Society Reviews, 39, 301–312.
  3. Sheldon, R. A. (2007). The E factor: Fifteen years on. Green Chemistry, 9, 1273–1283.
  4. Trost, B. M. (1991). The atom economy—A search for synthetic efficiency. Science, 254(5037), 1471–1477.
  5. Sheldon, R. A. (2018). Metrics of green chemistry and sustainability: Past, present, and future. ACS Sustainable Chemistry & Engineering, 6(1), 32–48.
  6. Jiménez-González, C., Ponder, C. S., Broxterman, Q. B., & Manley, J. B. (2011). Using the right green yardstick: Why process mass intensity is used in the pharmaceutical industry to drive more sustainable processes. Organic Process Research & Development, 15(4), 912–917.
  7. Diksha, D., & Naresh, K. (2022). Recent developments in Knoevenagel condensation reaction: A review. Journal of Advanced Scientific Research, 13(5), 17–25.
  8. Appaturi, J. N., Ratti, R., Phoon, B. L., Batagarawa, S. M., Din, I. U., Selvaraj, M., & Ramalingam, R. J. (2021). A review of the recent progress on heterogeneous catalysts for Knoevenagel condensation. Dalton Transactions, 50, 4445–4469.
  9. Pakravan, P., Kashanian, S., Khodaei, M. M., & Harding, F. J. (2013). Biochemical and pharmacological characterization of isatin and its derivatives: From structure to activity. Pharmacological Reports, 65(2), 313–335.
  10. Varun, Sonam, & Kakkar, R. (2019). Isatin and its derivatives: A survey of recent syntheses, reactions, and applications. MedChemComm, 10, 351–368.
  11. Gabr, M. T., El-Gohary, N. S., El-Bendary, E. R., El-Kerdawy, M. M., & Ni, N. (2017). Isatin-β-thiocarbohydrazones: Microwave-assisted synthesis, antitumor activity and structure–activity relationship. European Journal of Medicinal Chemistry, 128, 36–44.

https://doi.org/10.1016/j.ejmech.2017.01.030

  1. Tomasić, T., & Mašić, L. P. (2009). Rhodanine as a privileged scaffold in drug discovery. Current Medicinal Chemistry, 16(13), 1596–1629.
  2. Song, M.-X., Zheng, C.-J., Deng, X.-Q., Wang, Q., Hou, S.-P., Liu, T.-T., Xing, X.-L., & Piao, H.-R. (2012). Synthesis and bioactivity evaluation of rhodanine derivatives as potential anti-bacterial agents. European Journal of Medicinal Chemistry, 54, 403–412.
  3. Chaurasyia, A., Chawla, P., Monga, V., & Singh, G. (2023). Rhodanine derivatives: An insight into the synthetic and medicinal perspectives as antimicrobial and antiviral agents. Chemical Biology & Drug Design, 101(3), 500–549.
  4. Lim, J. Y., Ahmad Kamar, A. K. D. B., Gan, T. F., Chin, T. L., & Avupati, V. R. (2022). Review of anticancer potentials and structure–activity relationships (SAR) of rhodanine derivatives. Biomedicine & Pharmacotherapy, 145, 112406. https://doi.org/10.1016/j.biopha.2021.112406
  5. Das, P., & Ray, S. (2025). A brief review on different reactions of rhodanine. Journal of Heterocyclic Chemistry, 62(1), 78–98. https://doi.org/10.1002/jhet.4924
  6. Khodashenas, B., & Ghorbani, H. R. (2015). Synthesis of silver nanoparticles with different shapes. Arabian Journal of Chemistry, 12, 1823–1838. https://doi.org/10.1016/j.arabjc.2014.12.014
  7. Wei, L., Lu, J., Xu, H., Patel, A., Chen, Z.-S., & Chen, G. (2015). Silver nanoparticles: Synthesis, properties, and therapeutic applications. Drug Discovery Today, 20(5), 595–601. https://doi.org/10.1016/j.drudis.2014.11.014
  8. Deshmukh, S. P., Patil, S. M., Mullani, S. B., & Delekar, S. D. (2019). Silver nanoparticles as an effective disinfectant: A review. Materials Science and Engineering: C, 97, 954–965. https://doi.org/10.1016/j.msec.2018.12.102
  9. Sharma, V. K., Yngard, R. A., & Lin, Y. (2009). Silver nanoparticles: Green synthesis and their antimicrobial activities. Advances in Colloid and Interface Science, 145(1–2), 83–96. https://doi.org/10.1016/j.cis.2008.09.002
  10. Wei, L., Lu, J., Xu, H., Patel, A., Chen, Z.-S., & Chen, G. (2015). Silver nanoparticles: Synthesis, properties, and therapeutic applications. Drug Discovery Today, 20(5), 595–601. https://doi.org/10.1016/j.drudis.2014.11.014
  11. Mohanpuria, P., Rana, N. K., & Yadav, S. K. (2008). Biosynthesis of nanoparticles: Technological concepts and future applications. Journal of Nanoparticle Research, 10(3), 507–517. https://doi.org/10.1007/s11051-007-9275-x
  12. Iravani, S. (2011). Green synthesis of metal nanoparticles using plants. Green Chemistry, 13, 2638–2650. https://doi.org/10.1039/C1GC15386B
  13. Mittal, A. K., Chisti, Y., & Banerjee, U. C. (2013). Synthesis of metallic nanoparticles using plant extracts. Biotechnology Advances, 31(2), 346–356.

https://doi.org/10.1016/j.biotechadv.2013.01.003

  1. Chung, I.-M., Park, I., Kim, S.-H., Thiruvengadam, M., & Rajakumar, G. (2016). Plant-mediated synthesis of silver nanoparticles: Their characteristic properties and therapeutic applications. Nanoscale Research Letters, 11, 40. https://doi.org/10.1186/s11671-016-1257-4
  2. Gurunathan, S., Qasim, M., Park, C., Yoo, H., Kim, J.-H., & Hong, K. (2017). Cytotoxicity and antibacterial activity of silver nanoparticles synthesized using biomolecules. Frontiers in Microbiology, 8, 167. https://doi.org/10.3389/fmicb.2017.00167
  3. Ahmed, S., Saifullah, Ahmad, M., Swami, B. L., & Ikram, S. (2016a). Green synthesis of silver nanoparticles using Azadirachta indica aqueous leaf extract. Journal of Radiation Research and Applied Sciences, 9(1), 1–7.
  4. Shankar, S. S., Ahmad, A., & Sastry, M. (2003). Geranium leaf assisted biosynthesis of silver nanoparticles. Biotechnology Progress, 19(6), 1627–1631.
  5. Ahmad, N., Sharma, S., Alam, M. K., Singh, V. N., Shamsi, S. F., Mehta, B. R., & Fatma, A. (2010). Rapid synthesis of silver nanoparticles using dried medicinal plant of basil. Colloids and Surfaces B: Biointerfaces, 81(1), 81–86.
  6. Krishnaraj, C., Jagan, E. G., Rajasekar, S., Selvakumar, P., Kalaichelvan, P. T., & Mohan, N. (2010). Synthesis of silver nanoparticles using Acalypha indica leaf extracts and its antibacterial activity against water borne pathogens. Colloids and Surfaces B: Biointerfaces, 76(1), 50–56.
  7. Philip, D. (2010). Green synthesis of gold and silver nanoparticles using Hibiscus rosa-sinensis. Physica E: Low-Dimensional Systems and Nanostructures, 42(5), 1417–1424.
  8. Singh, S., Saikia, J. P., & Buragohain, A. K. (2013). A novel ‘green’ synthesis of colloidal silver nanoparticles (SNP) using Dillenia indica fruit extract. Colloids and Surfaces B: Biointerfaces, 102, 83–85.
  9. Ahmad, B., Hafeez, N., Rauf, A., Bashir, S., Linfang, H., Rehman, M.-U., Mubarak, M. S., Uddin, M. S., Bawazeer, S., Shariati, M. A., Daglia, M., Wan, C., & Rengasamy, K. R. R. (2021). Phyllanthus emblica: A comprehensive review of its therapeutic benefits. South African Journal of Botany, 138, 278–310.
  10. Ankamwar, B., Damle, C., Ahmad, A., & Sastry, M. (2005). Biosynthesis of gold and silver nanoparticles using Emblica officinalis fruit extract, their phase transfer and transmetallation in an organic solution. Journal of Nanoscience and Nanotechnology, 5(10), 1665–1671.
  11. Sharma, K., Singh, G., Singh, G., Kumar, M., & Bhalla, V. (2015). Silver nanoparticles: Facile synthesis and their catalytic application for the degradation of dyes. RSC Advances, 5, 25781–25788.
  12. Chouhan, N., Ameta, R., & Meena, R. K. (2017). Biogenic silver nanoparticles from Trachyspermum ammi (Ajwain) seeds extract for catalytic reduction of p-nitrophenol to p-aminophenol in excess of NaBH₄. Journal of Molecular Liquids, 230, 74–84.
  13. Yadav, S., & Khurana, J. M. (2015). Cinnamomum tamala leaf extract-mediated green synthesis of Ag nanoparticles and their use in pyranopyrazoles synthesis. Chinese Journal of Catalysis, 36(7), 1042–1046.
  14. Simon, M.-O., & Li, C.-J. (2012). Green chemistry oriented organic synthesis in water. Chemical Society Reviews, 41, 1415–1427.
  15. Cortes-Clerget, M., Yu, J., Kincaid, J. R. A., Walde, P., Gallou, F., & Lipshutz, B. H. (2021). Water as the reaction medium in organic chemistry: From our worst enemy to our best friend. Chemical Science, 12, 4237–4266.
  16. Gawande, M. B., Bonifácio, V. D. B., Luque, R., Branco, P. S., & Varma, R. S. (2013). Benign by design: Catalyst-free in-water, on-water green chemical methodologies in organic synthesis. Chemical Society Reviews, 42, 5522–5551.
  17. Mittal, A. K., Chisti, Y., & Banerjee, U. C. (2013). Synthesis of metallic nanoparticles using plant extracts. Biotechnology Advances, 31(2), 346–356. doi:10.1016/j.biotechadv.2013.01.003
  18. Thomas, S., Gonsalves, R. A., Jose, J., Zyoud, S. H., Prasad, A. R., & Garvasis, J. (2024). Plant-based synthesis, characterization approaches, applications and toxicity of silver nanoparticles: A comprehensive review. Journal of Biotechnology, 394, 135–149.
  19. Sharma, V. K., Yngard, R. A., & Lin, Y. (2009). Silver nanoparticles: Green synthesis and their antimicrobial activities. Advances in Colloid and Interface Science, 145(1–2), 83–96.
  20. Khodashenas, B., & Ghorbani, H. R. (2015). Synthesis of silver nanoparticles with different shapes. Arabian Journal of Chemistry, 12, 1823–1838.
  21. Poudel, S., et al. (2022). Plant-mediated green synthesis of Ag NPs and their possible applications: A critical review. Journal of Nanotechnology, 2779237.
  22. Zulfiqar, Z., Khan, R. R. M., Summer, M., Saeed, Z., Pervaiz, M., Rasheed, S., Shehzad, B., Kabir, F., & Ishaq, S. (2024). Plant-mediated green synthesis of silver nanoparticles: Synthesis, characterization, biological applications, and toxicological considerations: A review. Biocatalysis and Agricultural Biotechnology, 57, 103121.
  23. Huang, J., Li, Q., Sun, D., Lu, Y., Su, Y., Yang, X., & Hong, J. (2007). Biosynthesis of silver and gold nanoparticles by novel sundried Cinnamomum camphora Nanotechnology, 18, 105104.
  24. Bar, H., Bhui, D. K., Sahoo, G. P., Sarkar, P., & Misra, A. (2009). Green synthesis of silver nanoparticles using seed extract of Jatropha curcas. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 348, 212–216.
  25. Joint Committee on Powder Diffraction Standards (JCPDS). Card No. 04-0783.
  26. Balwe, S. G., Shinde, V. V., Rokade, A. A., Park, S. S., & Jeong, Y. T. (2017). Green synthesis and characterization of silver nanoparticles (AgNPs) from Radix Puerariae extract: An efficient and recyclable catalyst for the construction of pyrimido[1,2-b]indazole derivatives under solvent-free conditions. Catalysis Communications, 99, 121–126.
  27. Wang, C., Ciganda, R., Salmon, L., Gregurec, D., Irigoyen, J., Moya, S., Ruiz, J., & Astruc, D. (2016). Highly efficient transition metal nanoparticle catalysts in aqueous solutions. Angewandte Chemie International Edition, 55, 3091–3095.

DOI:

Article DOI: 10.62823/IJAER/02.03.253

DOI URL: https://doi.org/10.62823/IJAER/02.03.253

Download Full Paper:
Download PDF