Synthesis, Characterization and Biological Studies of Ce and Y-Luteolin Complexes

The rising threat of antimicrobial resistance necessitates novel agents with improved efficacy. The study aimed to synthesized, characterized and evaluate the antimicrobial activities of Ce(III) and Y(III)-Luteolin complexes. The complexes were prepared in 1:3 metal to ligand ratio by refluxing aqueous metal salts with luteolin in ethanolic solution at pH 6.9. The compounds were characterized using FT-IR, solubility test, molar conductivity, magnetic susceptibility and elemental analysis, UV-visible, Thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD. Antimicrobial activity was assessed by agar-well diffusion methods against bacterial strains (Staphylococcus aureus and Escherichia coli) and fungal strains (Candida albicans and Aspergillus niger). The complexes showed a percentage yield of 68.82 for Ce and 83.96 for Y-complexes respectively. The ligand and its synthesized complexes were found to be insoluble in water and n-hexane but soluble in DMSO. The ligand melt at 3160C while the complexes decomposed at 351 for Ce0C-complex and 3570C Y-complex suggesting the complexes to be thermally stable than the ligand and cannot decomposed easily. The FT-IR spectra of luteolin showed a broad band at 3198 cm-1, assignable to phenolic (OH). Another sharp absorbance band seen at 1659 cm-1 assigned to aromatic C=O stretch in the ligands were shifted to lower frequency range of 1651 - 1653 cm-1, suggesting coordination through oxygen of the C=O of the ligands respectively. New bands at the lower region in the range of 628 - 623 cm-1 which were not observed in the ligand, further confirmed M--O chelation in the complexes, which confirmed the deprotonation of phenolic (OH) in the ligands. The magnetic susceptibility data suggest paramagnetism of Ce-complex and diamagnetism property for Y-complexes. The UV-visible band shifted bathochromically comparted to the ligand. Molar conductivity results indicate the complexes to be non-electrolyte due to lower values obtain (1.55-8.60 ohm-1cm-1mol-1). The TGA results revealed sequential loss of lattice and coordinated water. The elemental analysis result showed that there is good agreement between the theoretical and experimental value suggesting the proposed structure was achieved. The XRD pattern confirmed crystalline materials distinct from free luteolin. All complexes exhibited concentration-dependent antimicrobial activities superior to the free luteolin.

Cerium. Luteolin, Yttrium, Coordination Chemistry, Antimicrobial Activity.

1. Adamu, U. A., Magaji, B., Mohammad, A. B., Sani, M. M., and Adoram, N. (2020). Synthesis, characterization and antibacterial study of Co(II) and Cu(II) complexes of sulfamethoxazole. Asian Journal of Advanced Research and Reports, 10(4), 38-43. https://doi.org/10.9734/ajarr/2020/v10i430251. [Google Scholar] [Crossref]

2. Ama, S. O., Wuana, R. A., Sha’ato, R., and Eneji, I.S. (2024). Green synthesis, structural characterization and study of thermal behavior of Cu2’ and Co2’ complexes derived from salicylidene-3-amino benzoie acid African Multidisciplinary Journal of Sciences and Artificial Intelligence. 1.620 633. Article source. [Google Scholar] [Crossref]

3. Andrew,S.Z.,Japhet,T.,Bako,B.,Abakpa,A.M.,&Shinggu,J.P.(2023).Synthesisandpreliminaryantibacterialscreeningofsalicylaldehyde aminobenzoic acid anditsmetalcomplexe.10(3),40–46. [Google Scholar] [Crossref]

4. Bamigboye, O. M., Ejidike, I. P., & Lawal, M. (2020). Synthesis, characterization, and antimicrobial potentials of some flavonoid–metal complexes. Iraqi Journal of Science, 61(4), 789–799. [Google Scholar] [Crossref]

5. Bünzli, J.-C.G., and Pecharsky, V. K. (2016).Handbook on the Physics and Chemistry of Rare Earths.Elsevier. [Google Scholar] [Crossref]

6. Bera, S. P., Mondal, A., and Konar, S. (2022). Investigation of the role of terminal ligands in magnetic relaxation in a series of dinuclear dysprosium complexes.Inorganic Chemistry Frontiers, 7(18), 3352–3363. doi.org [Google Scholar] [Crossref]

7. Bonetti F, Brombo G, Zuliani G (2017) Nootropics, functional foods, and dietary patterns for prevention of cognitive decline. In: Watson RR (ed) Nutrition and Functional Foods for Healthy Aging. Academic Press, Cambridge, pp 211 –232. [Google Scholar] [Crossref]

8. Cotton, S. A. (2024). Lanthanide and Actinide Chemistry, 2nd ed.; Wiley, susceptibility and tetracycline-resistance gene distribution. Microb Pathog.2017;105:51–56. doi:10.1016/j.micpath.2017.02.010 [Google Scholar] [Crossref]

9. Dongare, G., and Aswar, A. (2021). Synthesis, spectral characterization, thermo-kinetic and biological studies of some complexes derived from tridentate hydrazone Schiff base. Journal of Saudi Chemical Society, 25(10), 101325. doi.org. [Google Scholar] [Crossref]

10. Edewor, T.I., Bankole T.A., Ogunjimi, D.V., Mmuo, A.I., & Amuda, M.O. (2023). GC-MS profile, synthesis and speetral characterization of flavonoid-metal (cadmium, cobalt, copper, nickel) complexes of Jatropha curea leaves International Journal of Chemistry Research, 7(2).4 12.IJCR.1. [Google Scholar] [Crossref]

11. Fabiyi, F. S., and Olanrewaju, A. A. (2019). Synthesis, characterization, Thermogravimetric and antioxidant studies of new Cu(II), Fe(II), Mn(II), Zn(II), Co(II) and Ni(II) complexes with benzoic acid and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione. International Journal of Chemistry, 11(1), 60–70. doi.org [Google Scholar] [Crossref]

12. Fetouh, H. A., Dissouky, A. E., Salem, H. A., Fathy, M., Anis, B., & Hady Kashyout, A. E. (2024). Synthesis, characterization and evaluation of new transition metal complexes of luteolin derivatives. Journal of Molecular Structure (or alternate specific journal depending on exact volume, such as Scientific Reports / MDPI Advances in Phenolic Based Complexes). [1, 2 [Google Scholar] [Crossref]

13. Gao, W., Pan, L. S., Lei, L., and Zhu, C. (2026). Synthesis, characterization and antioxidative activity of lanthanide complex with luteolin.Chemical Journal of Chinese Universities, 44(4), 663–665.Górniak, I., Bartoszewski, R. &Króliczewski, J. (2019).Comprehensive reviewof antimicrobial activities of plantfavonoids.Phytochem. Rev. 18, 241–272. [Google Scholar] [Crossref]

14. Gonelimali, FD, Lin J, Miao W, Xuan J, Charles F, Chan M, Hatab SR.(2018). Antimicrobial properties and mechanisms of action of some plant extracts against food pathogens and spoilage microorganisms. Frontiers in microbiology. [Google Scholar] [Crossref]

15. Govindrajan, K., and Ramesh, M. (2021). Design, synthesis, characterization and biological activities of some transition metal complexes via novel mannich base ligand. International Journal of biology, Pharmacy and Allied Sciences (IJBPAS), 117p137. [Google Scholar] [Crossref]

16. Giuseppina Anna Corrente, G. A., Luana Malacaria, Amerigo Beneduci, TizianaMarino, and Emilia Furia, (2025). Quercetin and luteolin complexation with first-row transition metalsin purely aqueous solutions Stoichiometry and binding siteselectivity.DaltonTransactions,54(19),7828–7837. https://doi.org/10.1039/D5DT00478K. [Google Scholar] [Crossref]

17. Haruna, M., Ndahi, J. A., Dowell, B. F., &Sadauki, F. T. (2024). Synthesis, physicochemical and antimicrobial studies of Schiff base derived from 2,4-dinitrophenylhydrazine with salicylaldehyde and its Co(II) and Ni(II) complexes. IDOSR Journal of Scientific Research, 9(2), 112. https://doi.org/10.59298/IDOSRJSR/2024/9.2.1211.10.DoSR+1. [Google Scholar] [Crossref]

18. Holder, C. F., Schaak, R. E., (2019).tutorial on power x-ray Diffraction for characterizing materials. ACS publication https.doi.org/10.1021/acsnano. [Google Scholar] [Crossref]

19. Iorungwa, M. S., Dafa, S. T., Wuana, R. A., Iornumbe, E. N., & Tivkaa, J. T. (2024). Thermal stability profiling of Co(II), Mn(II), and Ni(II)-Hydrazone Based complexes: The role of kinetic and thermodynamics parameters. ChemSearch Journal, 14(2), 46–57. https://www.ajol.info/index.php/csj/article/view/262735 [1] [Google Scholar] [Crossref]

20. Jafar,M.,Salahuddin,M.,Khan,M.S.A., Alshehry , Y., Alrwaili, N.R., Alzahrani, Y. A., Imam S. S., and Alshehry, S.(2021).Preparation and In Vitro-In-Vivo Evaluation of Luteolin Loaded GastroretentiveMicrosponge for the Eradication of Helicobacter pylori Infections. Pharmaceutics 13.(12), 2094. https;doi.org/10.33290. [Google Scholar] [Crossref]

21. Jayaprakash, S., Ramesh, S., Karthikeyan, A., Murugappan, S., Sidharthan, P., and Selvaraj, S. (2023). Transition metal coordination complexes of flavonoids: A class of better pharmacological active molecules to develop new drugs. Anti-Cancer Agents in Medicinal Chemistry, 23(4).417-431. [Google Scholar] [Crossref]

22. Kumar, P., Singh, R., & Mehta, A. (2021). Flavonoid-metal interactions: Implications for bioactivity. Bioinorganic Chemistry Applications, 2021, 1-12. [Google Scholar] [Crossref]

23. Khorasani-Motlagh M, Noroozifar M, Moodi A, Niroomand S. (2013).Journal of Photochemistry and Photobiology B: Biology 127, 192-201. [Google Scholar] [Crossref]

24. M. M. El-Zahed, A. A. El-Bindary, N. M. Mansour, H. M. Salama and Sh. M. Morgan (2025). Design, antibacterial activity, DNA interaction, anticancer and molecular docking analysis of novel bivalent metal chelates based on an N,O-donor Schiff base ligand. Discover Materials.Springer. [Google Scholar] [Crossref]

25. Malacaria, I.,,I.a Torre. C., Furia, F., Fazio, A., Caroleo. M.C., Cione. F., Gallelli, I. Marino, T., &Plastina, P. (2022). Aluminum (III), iron (III) and copper (II). Complexes of Luteolin: Stability, antioxidant, and anti-inflammatory properties. Journal ofMolecular Liquids, 345.117895. https://doi.org/10.1016/j.molliq.2021.117895. Science Direct. [Google Scholar] [Crossref]

26. Manvell, A. S., Pfleger, R., Bonde, N. A., Briganti, M., Mattei, C. A., Nannestad, T. B., Weihe, H., Powell, A. K., Ollivier, J., Bendix, J., & Pedersen, K. S. (2024). LnDOTA puppeteering: Removing the water molecule and imposing tetragonal symmetry. Chemical Science, 15(1), 113–123. doi.org [Google Scholar] [Crossref]

27. Materazzi, S., Vecchio, Ciprioti, S., Wo, L. W., and De-angelis Curtis.,(2012).TG-MS and TG-FTIR studies of immidazole substituted coordination compounds Co(ll) and Ni(ll) complexes bis(1-methylimmidazole-2-yl)ketone thermochimica Acta 543-183-187. [Google Scholar] [Crossref]

28. Matsia, S., Papadopoulos, A., Hatzidimitriou, A., Schumacher, L., Koldemir, A., Pöttgen, R., Panagiotopoulou, A., Chasapis, C. T., &Salifoglou, A. (2025). Hybrid Lanthanide Metal–Organic Compounds with Flavonoids: Magneto-Optical Properties and Biologica Activity Profiles. International Journal of Molecular Sciences, 26_(3), 1198. https://doi.org/10.3390/ijms26031198[1]. [Google Scholar] [Crossref]

29. Mortis, A., & Anwander, R. (2024). Rare-earth-metal alkyl and aryl compounds in organic synthesis. European Journal of Inorganic Chemistry, 27(16), e202400127. doi.org [Google Scholar] [Crossref]

30. Muraleedharan, Jincy Ennakkathara; Viswanathan, Kaladharan Perumpaparampil (2025). Microwave Assisted Synthesis of Some Ln(III) Chloride Complexes from 4-Formyl Antipyrine Schiff base: Structural Characterization and Antimicrobial Evaluation. Published in: Oriental Journal of Chemistry, 2025, v. 41, n. 1, p. 254, doi. 10.13005/ojc/410130 [Google Scholar] [Crossref]

31. Persaud, A. A., Sasidharanpillai, S., Cox, J. S., and Tremaine, P. R. (2024). Speciation and formation constants of aqueous lanthanum(III) chloride complexes from 5 to 80 °C by Raman spectroscopy. Canadian Journal of Chemistry, 102(12), 922–934. doi.org ScienceDirect.com. [Google Scholar] [Crossref]

32. Pospieszna-Markiewicz, I., Fik-Jaskółka, M. A., Hnatejko, Z., Patroniak, V., & Kubicki, M. (2022).Synthesis and Characterization of Lanthanide Metal Ion Complexes of New Polydentate Hydrazone Schiff Base Ligand._Molecules, 27(23), 8390. https://doi.org/10.3390/molecules27238390[3]. [Google Scholar] [Crossref]

33. Rajhard, S.; Hladnik, L.; Vicente, F.A.; Srčič, S.; Grilc, M.; Likozar, B. (2021). Solubility of Luteolin and Other Polyphenolic Compounds in Water, Nonpolar, Polar Aprotic and Protic Solvents by Applying FTIR/HPLC. Processes 2021, 9 (11), 1952. [1] [Google Scholar] [Crossref]

34. Sabrina, Coprali., Alesandro, De Stefano., Cinzia, Calabrese., Alfredo, Giovannelli., Massimo, Pieri., IsabelDy,Savini., Manfredi, Tesauro., Sergio, Bernardini., Marilena, Mineri., Alesandro, Terrinoni (2022). Anti-Inflammatory and Active Biological Properties of the Plant-Derived Bioactive Compounds Luteolin and Luteolin 7-Glucoside.National Library ofMedicine USA. [Google Scholar] [Crossref]

35. Silverstein, R. M.; Webster, F. X.; Kiemle, D. J.; Bryce, D. L.(2014). Spectrometric Identification of Organic Compounds, 8th edition.; Wiley,.structural aspects. Coordination Chemistry Reviews. [Google Scholar] [Crossref]

36. Skoog, D. A., Holler, F. J., and Crouch, S. R.(2018.). Principles of Instrumental Analysis, (7th ed). Cengage Learning. [Google Scholar] [Crossref]

37. Tawornchat, P., Pattarakankul, T., Palaga, T., Intasanta, V., &Wanichwecharungruang, S. (2021). Polymerized luteolin nanoparticles: Synthesis, structure elucidation, and anti-inflammatory activity.ACS Omega, 6(4), 2846 2855. https://doi.org/10.1021/acsomega.0c05142 [Google Scholar] [Crossref]

38. Tiwari, L., and Waynant, K. V. (2023). The synthesis and structuralproperties of a chloridobis{N [(4methoxyphenyl)imino]pyrrolidine1carboxamide}zinc(II)(acetonitrile)trichlordozincate coordination complex. Journal of Coordination Chemistry, 76(11–12), 1435–1448. doi.org. [Google Scholar] [Crossref]

39. Vakarelska-Popovska, M., Karadjova, V. & Velkov, Z. (2022). Synthesis, structure and prooxidant activity of 3-hydroxyflavone complexes with Cu(II). J. Chem. Technol. Metall. 57, 3. [Google Scholar] [Crossref]

40. Walencik, Paulina Katarzyna.,Choińska, R., Gołębiewska, E., & Kalinowska, M. (2024).Metal–Flavonoid Interactions-From Simple Complexes to Advanced Systems.Molecules, 29 (11), 2573.https://doi.org/10.3390/molecules29112573[2 [Google Scholar] [Crossref]

41. Wenbin, Zhang., Duanbin, Li., Yu, Shan., Yecheng, Tao., Qinqinq, Chen., Tianli, Hu., Menghan, Gao., Zhezhe, Chen., Hangpan, Jiang., Changpin, Du., Win, Wang., Kai, Gua. (2023). Luteolin intake is negatively associated with all-cause and cardiac mortality among patients with type 2 diabetes mellitus.PMCID. [Google Scholar] [Crossref]

42. Weller, M. T., Overton, T., Rourke, J., & Armstrong, F. (2018). Inorganic Chemistry (2nd ed.). Oxford University Press. [Google Scholar] [Crossref]

43. West, A. R. (2017). Solid State Chemistry and Its Applications, 2nd ed. Wiley. [Google Scholar] [Crossref]

44. Yuanyong Yao., Meng Zeng., Laibing He., Yunyang Wang., and Shixue Chen (2020). Evaluation of General Synthesis Procedure for Bioflavonoids-Metal complexes in air-saturated alkane Solutions.Frontiers in Chemistry 8, 589.https//doi.org/10.fchm.2020.00589. [Google Scholar] [Crossref]

• The Impact of Ownership Structure on Dividend Payout Policy of Listed Plantation Companies in Sri Lanka
• Urban Sustainability in North-East India: A Study through the lens of NER-SDG index
• Performance Assessment of Predictive Forecasting Techniques for Enhancing Hospital Supply Chain Efficiency in Healthcare Logistics
• The Fractured Self in Julian Barnes' Postmodern Fiction: Identity Crisis and Deflation in Metroland and the Sense of an Ending
• Impact of Flood on the Employment, Labour Productivity and Migration of Agricultural Labour in North Bihar