Designing a Novel Schiff Base and Metal Complexes Derived from Drug Scaffold as Antioxidant Activity and Eco-Conscious Corrosion Inhibitors
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Abstract
The article involves a novel synthesized Schiff base from a pharmaceutical compound, involving the condensation of amoxicillin with 4-(dimethylamino)-2-hydroxy aldehyde in a basic medium. Spectroscopic techniques such as elemental analysis, mass spectrometry, 1H-NMR, FT-IR, and UV-Vis spectrometry were used to characterize the new compound. These methods helped identify the formation of copper (II), silver (I), and gold (III) complexes with the Schiff base ligand (Amox-S). All compounds were evaluated for antioxidant activity using DPPH radical scavenging, showing 71%-86% activity, which was considered good and comparable to the standard ascorbic acid. The corrosion inhibition ability of the Schiff base and its Cu(II) complex on carbon C45 in acidic media (1M hydrochloric acid) was also examined using weight loss measurements at 1x10-4 - 1x10-3 M, for varying immersion times (1-10 days) at lab temperature of 25±2οC to determine the most effective concentration. It was found that the optimal concentration of the ligand and its complex as anti-corrosives was 1x10-3 M, which significantly enhanced the protective qualities of the coating. This optimal concentration was then evaluated for corrosion protection using polarization methods and the absence and presence of the Schiff base ligand and its copper(II) complex at three temperatures (293, 303, and 313 K). The Amox-S maintained an inhibition efficiency of 91-92% across the temperature range, whereas the Cu-complex exhibited slightly superior performance with IE% values of 93-94%.
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References
Abd El-Zahir, M. S., Soliman, M. H. A., ELKady, H. A., El-Sakka, S. S. A., & Orabi, A. S. (2024). New inorganic inhibitors derived from cefotaxime to enhance corrosion resistance of mild steel in 3% NaCl. Scientific Reports, 14(1), Article 950. https://doi.org/10.1038/s41598-024-51275-5
Abdallah, M., Soliman, K. A., Alfakeer, M., Hawsawi, H., Al-Bonayan, A. M., Al-Juaid, S. S., El Wanees, S. A., & Motawea, M. S. (2023). Expired antifungal drugs as effective corrosion inhibitors for carbon steel in 1 M HCl solution: practical and theoretical approaches. ACS Omega, 8(38), 34516-34533. https://doi.org/10.1021/acsomega.3c03257
Adamu, A. A., Iyun, O. R. A., & Habila, J. D. (2025). Adsorption and thermodynamic studies of the corrosion Inhibition effect of Desmodium adscendens (Swartz) extract on carbon steel in 2 M HCl. BMC Chemistry, 19(1), Article 163. https://doi.org/10.1186/s13065-025-01541-y
Affat, S. S. (2022). Experimental and theoretical studies of new Schiff base as a corrosion inhibitor in acidic media and study antioxidant activity. Iranian Journal of Chemistry and Chemical Engineering, 41(10), 3351-3364. https://doi.org/10.30492/ijcce.2021.534910.4860
Ahmed, M. A., Amin, S., & Mohamed, A. A. (2024). Current and emerging trends of inorganic, organic and eco-friendly corrosion inhibitors. RSC Advances, 14(43), 31877-31920. https://doi.org/10.1039/d4ra05662k
Alabidi, H. M., Alabidi, A. M., & Makki, N. (2018). Synthesis and spectroscopic studying of new azo ligand from 2-naphthol derivative and it's complexes with some transition metal ions. Al-Qadisiyah Journal of Pure Science, 23(1), 186-195. https://doi.org/10.29350/jops.2018.23.1.731
Alabidi, H. M., Farhan, A. M., Al-labban, H. M. Y., & Aljanaby, A. A. J. (2023). New derivatives from 4-amino anti-pyrine and vanillin, synthesis characterization and antibacterial activity. Egyptian Journal of Chemistry, 66(1), 175-181. https://doi.org/10.21608/EJCHEM.2022.135727.5977
Al-Amiery, A. A., Al-Azzawi, W. K., & Isahak, W. N. R. W. (2022). Isatin Schiff base is an effective corrosion inhibitor for mild steel in hydrochloric acid solution: gravimetrical, electrochemical, and computational investigation. Scientific Reports, 12(1), Article 17773. https://doi.org/10.1038/s41598-022-22611-4
Alamry, K. A., Khan, A., Aslam, J., Hussein, M. A., & Aslam, R. (2023). Corrosion inhibition of mild steel in hydrochloric acid solution by the expired ampicillin drug. Scientific Reports, 13(1), Article 6724. https://doi.org/10.1038/s41598-023-33519-y
Al-Daffay, R. K. H., Al-Hamdani, A. A. S., & Elluhaibi, E. A. E. (2025). Synthesis, characterization and studying thermal analysis for complexes of some metal ions and determining their activity as antioxidants. Baghdad Science Journal, 22(3), 801-812. https://doi.org/10.21123/bsj.2024.9644
Alfakeer, M., Abdallah, M., & Fawzy, A. (2020). Corrosion inhibition effect of expired ampicillin and flucloxacillin drugs for mild steel in aqueous acidic medium. International Journal of Electrochemical Science, 15(4), 3283-3297. https://doi.org/10.20964/2020.04.09
Ali, M., Sholkamy, E. N., Alobaidi, A. S., Al-Muhanna, M. K., & Barakat, A. (2023). Synthesis of Schiff bases based on chitosan and heterocyclic moiety: Evaluation of antimicrobial activity. ACS Omega, 8(49), 47304-47312. https://doi.org/10.1021/acsomega.3c08446
Almomani, M. A., Al-Noaimi, M., Hayajneh, M. T., Alshurafat, H. H., & Alshamaileh, E. M. (2021). Experimental evaluation of new organic compounds as corrosion inhibitors for mild steel in hydrochloric acid. International Journal of Corrosion and Scale Inhibition, 10(3), 1141-1156. https://doi.org/10.17675/2305-6894-2021-10-3-18
Betti, N., Al-Amiery, A. A., Al-Azzawi, W. K., & Isahak, W. N. R. W. (2023). Corrosion inhibition properties of schiff base derivative against mild steel in HCl environment complemented with DFT investigations. Scientific Reports, 13(1), Article 8979. https://doi.org/10.1038/s41598-023-36064-w
Chaudhary, N. K., & Mishra, P. (2017). Metal complexes of a novel Schiff base based on penicillin: characterization, molecular modeling, and antibacterial activity study. Bioinorganic Chemistry and Applications, 2017(1), Article 6927675. https://doi.org/10.1155/2017/6927675
Chavelas-Hernández, L., Valdéz-Camacho, J. R., Hernández-Vázquez, L. G., Dominguez-Mendoza, B. E., Vasquez-Ríos, M. G., & Escalante, J. (2020). A new approach using aromatic-solvent-induced shifts in NMR spectroscopy to analyze β-lactams with various substitution patterns. Synlett, 31(2), 158-164. https://doi.org/10.1055/s-0039-1691498
Diki, N. G. Y. S., Coulibaly, N. H., Kambiré, O., & Trokourey, A. (2021). Experimental and theoretical investigations on copper corrosion inhibition by cefixime drug in 1M HNO3 solution. Journal of Materials Science and Chemical Engineering, 9(5), 11-28. https://doi.org/10.4236/msce.2021.95002
El Aloua, A., Oubahou, M., El Bouari, A., & Tanane, O. (2024). Expired amoxicillin as an eco-friendly corrosion inhibitor for cast steel in sulfuric acid environment: electrochemical, surface and thermodynamic studies. Journal of Solid State Electrochemistry, 28(7), 2397-2411. https://doi.org/10.1007/s10008-023-05788-0
El-Lateef, H. M. A., El-Dabea, T., Khalaf, M. M., & Abu-Dief, A. M. (2022). Innovation of imine metal chelates as corrosion inhibitors at different media: A collective study. International Journal of Molecular Sciences, 23(16), Article 9360. https://doi.org/10.3390/ijms23169360
El-Lateef, H. M. A., El‐Dabea, T., Khalaf, M. M., & Abu-Dief, A. M. (2023). Recent overview of potent antioxidant activity of coordination compounds. Antioxidants, 12(2), Article 213. https://doi.org/10.3390/antiox12020213
Emrayed, H. F., Amraga, E. A., Ibrahim, D. M., & Fouda, A. E. A. S. (2025). Corrosion inhibition effect of Schiff base and its metal complexes with [Mn (II) and Cu (II)] on carbon steel in hydrochloric acid solution: Experimental and surface studies. International Journal of Electrochemical Science, 20(1), Article 100912. https://doi.org/10.1016/j.ijoes.2024.100912
Farhan, A. M., Egzar, H. K., & Alabidi, H. M. (2024). New compounds derived from nitrophenol synthesis, structural investigation and anticorrision properties. Acta Chimica Slovenica, 71(2), 179-185. https://doi.org/10.17344/acsi.2023.8489
Go, L. C., Depan, D., Holmes, W. E., Gallo, A., Knierim, K., Bertrand, T., & Hernandez, R. (2020). Kinetic and thermodynamic analyses of the corrosion inhibition of synthetic extracellular polymeric substances. PeerJ Materials Science, 2, Article e4. https://doi.org/10.7717/peerj-matsci.4
Hadi, M. A., Mohammed, M. S., & Kadhium, A. J. (2021). Synthesis, characterization and spectral studies and biological screening study of transition metal complexes with new heterocyclic ligand derived from pyridoxal hydrochloride. Systematic Reviews in Pharmacy, 12(1), 371-383.
Hernández, J. G., Aguilar, C. A. H., Narayanan, J., Flores, E. D. T., Thangarasu, P., Ramírez, A. H., Shammugam, K., & Martinez, M. M. L. (2024). Effect of metal ions in the electron-transfer mechanism on the photovoltaic performance of SALPHEN-based DSSC: experimental and theoretical studies. Materials Advances, 5(8), 3257-3280. https://doi.org/10.1039/d3ma00982c
Hilal, T. A. A., & Kareem, I. K. (2025). Synthesis of some metal complexes with new heterocyclic ligand (5-(((2-(3-(1 H-indol-3-yl) acryloyl) phenyl) amino) methylene)-2-thiooxodihydropyrimidine-4, 6 (1 H, 5 H)-dione) and their biological effectiveness as antioxidant and anti-cancer. Indonesian Journal of Chemistry, 25(1), 60-75. https://doi.org/10.22146/ijc.95731
Kalluru, S., Dammu, L. K., Nara, S. K., & Nimmagadda, V. V. J. (2023). Synthesis and characterization of Schiff base, 3-hydroxy-4-(3-hydroxy benzylidene amino) benzoic acid and their Ni (II) and Zn (II) metal complexes. Journal of Advanced Scientific Research, 14(1), 35-39. https://doi.org/10.55218/JASR.202314105
Kanagavalli, C., Kalanithi, M., Gurusamy, S., Asha, R. N., Megtalin, N. M., & Sankarganesh, M. (2024). Computational, spectroscopic, sensor and biological studies of Cu (II) complex of Fluoro substituted Schiff base. Chemical Physics Impact, 8, Article 100582. https://doi.org/10.1016/j.chphi.2024.100582
Karaman, R., Al-Kurd, S., Yaghmour, R., Amro, A., & Karaman, D. (2015). Antibacterial activity of novel prodrugs of amoxicillin and cephalexin. World Journal of Pharmaceutical Research, 4(9), 334-360.
Kasare, M. S., Dhavan, P. P., Jadhav, B. L., & Pawar, S. D. (2019). Synthesis of azo Schiff base ligands and their Ni (II), Cu (II) and Zn (II) metal complexes as highly‐active antibacterial agents. ChemistrySelect, 4(36), 10792-10797. https://doi.org/10.1002/slct.201901605
Khudhair, N. A., & Al-Sammarraie, A. M. A. (2019). Enhancing of corrosion protection of steel rebar in concrete using TiO2 nanoparticles as additive. Iraqi Journal of Science, 60(9), 1898-1903. https://doi.org/10.24996/ijs.2019.60.9.2
Khudhair, N. A., Bader, A. T., Ali, M. I., & Husseini, M. (2020). Synthesis, identification and experimental studies for carbon steel corrosion in hydrochloric acid solution for polyimide derivatives. AIP Conference Proceedings, 2290(1), Article 030014. https://doi.org/10.1063/5.0027443
Kyhoiesh, H. A. K., & Al-Adilee, K. J. (2021). Synthesis, spectral characterization, antimicrobial evaluation studies and cytotoxic activity of some transition metal complexes with tridentate (N, N, O) donor azo dye ligand. Results in Chemistry, 3, Article 100245. https://doi.org/10.1016/j.rechem.2021.100245
Kyhoiesh, H. A. K., & Al-Adilee, K. J. (2023). Pt (IV) and Au (III) complexes with tridentate-benzothiazole based ligand: synthesis, characterization, biological applications (antibacterial, antifungal, antioxidant, anticancer and molecular docking) and DFT calculation. Inorganica Chimica Acta, 555, Article 121598. https://doi.org/10.1016/j.ica.2023.121598
Kzar, W. D., Mohammed, H. S., Zghair, F. S., & Zizi, Z. (2023). Synthesis, characterization and staining ability of novel azo dye based on curcumin and its Au (III) complex. Indonesian Journal of Chemistry, 23(5), 1375-1383. https://doi.org/10.22146/ijc.84388
Ladan, M., Ayuba, A. M., & Zakariyya, D. (2025). Evaluation of corrosion inhibition potential of Schiff bases derived from 2-hydroxybenzaldehyde on mild steel in 1M HCl solution. Journal of Materials and Environmental Science, 16(2), 304-319.
Lasri, M., Hassnaoui, A., Idlahoussaine, N., Ait-Karra, A., Maatallah, M., Zakir, O., Idouhli, R., Khadiri, M. E., Ali, M. A., & Abouelfida, A. (2025). Novel Schiff base derivatives: Enhanced corrosion protection for copper in NaCl solutions–electrochemical insights and theoretical analysis. Journal of Industrial and Engineering Chemistry, 146, 551-563. https://doi.org/10.1016/j.jiec.2024.11.039
Mahmoud, Z. S., Shams, A. K., & Salman, T. A. (2022). Study the inhibition effect of amoxicillin drug for corrosion of carbon steel in saline media. Baghdad Science Journal, 19(1), Article 9. https://doi.org/10.21123/bsj.2022.19.1.0121
Malik, M. A., Dar, O. A., Gull, P., Wani, M. Y., & Hashmi, A. A. (2018). Heterocyclic Schiff base transition metal complexes in antimicrobial and anticancer chemotherapy. MedChemComm, 9(3), 409-436. https://doi.org/10.1039/C7MD00526A
Moreno-Narváez, M. E., González-Sebastián, L., Colorado-Peralta, R., Reyes-Márquez, V., Franco-Sandoval, L. O., Romo-Pérez, A., Cruz-Navarro, J. A., Mañozca-Dosman, I. V., Aragón-Muriel, A., & Morales-Morales, D. (2025). Anticancer and antimicrobial activity of copper(ii) complexes with fluorine-functionalized Schiff bases: A mini-review. Inorganics, 13(2), Article 38. https://doi.org/10.3390/inorganics13020038
Mushtaq, I., Ahmad, M., Saleem, M., & Ahmed, A. (2024). Pharmaceutical significance of Schiff bases: an overview. Future Journal of Pharmaceutical Sciences, 10, Article 16. https://doi.org/10.1186/s43094-024-00594-5
Olasunkanmi, L. O., Idris, A. O., Adewole, A. H., Wahab, O. O., & Ebenso, E. E. (2020). Adsorption and corrosion inhibition potentials of salicylaldehyde-based Schiff bases of semicarbazide and p-toluidine on mild steel in acidic medium: Experimental and computational studies. Surfaces and Interfaces, 21, Article 100782. https://doi.org/10.1016/j.surfin.2020.100782
Patriarca, C., & Hawkes, J. A. (2020). High molecular weight spectral interferences in mass spectra of dissolved organic matter. Journal of the American Society for Mass Spectrometry, 32(1), 394-397. https://doi.org/10.1021/jasms.0c00353
Podolski-Renić, A., Gašparović, A. Č., Valente, A., López, Ó., Nunes, J. H. B., Kowol, C. R., Heffeter, P., & Filipović, N. R. (2024). Schiff bases and their metal complexes to target and overcome (multidrug) resistance in cancer. European Journal of Medicinal Chemistry, 270, Article 116363. https://doi.org/10.1016/j.ejmech.2024.116363
Praveen, B. M., Jeevan Chakravarthy, A. S., Prasanna, B. M., Shabanbanu, Devendra, B. K., Pavithra, M. K., & Fasiulla. (2025). Experimental and theoretical investigation of cyclohexanone derivative (CHD) as a corrosion inhibitor for mild steel in 1 M HCl. Scientific Reports, 15(1), Article 720. https://doi.org/10.1038/s41598-024-83054-7
Presenjit, Chaturvedi, S., Singh, A., Gautam, D., Singh, K., & Mishra, A. K. (2024). An insight into the effect of Schiff Base and their d and f block metal complexes on various cancer cell lines as anticancer agents: A review. Anti-cancer Agents in Medicinal Chemistry, 24(7), 488-503. https://doi.org/10.2174/0118715206280314231201111358
Radi, A., El Mahi, B., Aouniti, A., El Massoudi, M., Radi, S., Kaddouri, M., Chelfi, T., Jmiai, A., El Asri, A., Hammouti, B., Warad, I., Guenbour, A., & Zarrouk, A. (2022). Mitigation effect of novel bipyrazole ligand and its copper complex on the corrosion behavior of steel in HCl: Combined experimental and computational studies. Chemical Physics Letters, 795, Article 139532. https://doi.org/10.1016/j.cplett.2022.139532
Raheema, M. H., Khudhair, N. A., AL-Noor, T. H., Al-Ayash, S. R., Kharnoob, H. H., & Obed, S. M. (2023). Enhancement of corrosion protection of metal carbon steel C45 and stainless steel 316 by using inhibitor (Schiff base) in sea water. Baghdad Science Journal, 20(3), Article 30. https://doi.org/10.21123/bsj.2023.7749
Ramadan, R. M., El-Shalakany, H. H. & Sayed, M. A. (2025). Structural and biomedical investigations of novel ruthenium schiff base complexes. Scientific Reports, 15, Article 18546. https://doi.org/10.1038/s41598-025-03147-9
Reiss, A., Chifiriuc, M. C., Amzoiu, E., & Spînu, C. I. (2014). Transition metal (ii) complexes with cefotaxime‐derived Schiff Base: Synthesis, characterization, and antimicrobial studies. Bioinorganic Chemistry and Applications, 2014(1), Article 926287. https://doi.org/10.1155/2014/926287
Reiss, A., Samide, A., Ciobanu, G., & Dabuleanu, I. (2015). Synthesis, spectral characterization and thermal behaviour of new metal (II) complexes with Schiff base derived from amoxicillin. Journal of the Chilean Chemical Society, 60(3), 3074-3079.
Savcı, A., Buldurun, K., Alkış, M. E., Alan, Y., & Turan, N. (2022). Synthesis, characterization, antioxidant and anticancer activities of a new Schiff base and its M(II) complexes derived from 5-fluorouracil. Medical oncology, 39(11), Article 172. https://doi.org/10.1007/s12032-022-01774-0.
Shwetha, K. M., Praveen, B. M., & Devendra, B. K. (2024). A review on corrosion inhibitors: types, mechanisms, electrochemical analysis, corrosion rate and efficiency of corrosion inhibitors on mild steel in an acidic environment. Results in Surfaces and Interfaces, 16, Article 100258. https://doi.org/10.1016/j.rsurfi.2024.100258
Soroceanu, A., & Bargan, A. (2022). Advanced and biomedical applications of Schiff-Base ligands and their metal complexes: A review. Crystals, 12(10), Article 1436. https://doi.org/10.3390/cryst12101436
Tabrizi, L., Dao, D. Q., & Vu, T. A. (2019). Experimental and theoretical evaluation on the antioxidant activity of a copper (II) complex based on lidocaine and ibuprofen amide-phenanthroline agents. RSC Advances, 9(6), 3320-3335. https://doi.org/10.1039/c8ra09763a
Todorov, L., Saso, L., & Kostova, I. (2023). Antioxidant activity of coumarins and their metal complexes. Pharmaceuticals, 16(5), Article 651. https://doi.org/10.3390/ph16050651
Verma, C., Al-Moubaraki, A. H., Alfantazi, A., & Rhee, K. Y. (2024). Heterocyclic amino acids-based green and sustainable corrosion inhibitors: Adsorption, bonding and corrosion control. Journal of Cleaner Production, 446, Article 141186. https://doi.org/10.1016/j.jclepro.2024.141186
Younus, H. A., Saleem, F., Hameed, A., Al-Rashida, M., Al-Qawasmeh, R. A., El-Naggar, M., Khan, K. M. (2023). Part-II: an update of Schiff bases synthesis and applications in medicinal chemistry-a patent review (2016-2023). Expert Opinion on Therapeutic Patents, 33(12), 841-864. https://doi.org/10.1080/13543776.2023.2297729
Youssif, M. M., El-Nahass, M. N., Fayed, T. A., El-Daly, H. A., El-Gamil, M. M., & Eldesoky, A. M. (2023). Tunable anticorrosive effects of newly synthesized Benzothiazole Azo dyes by potassium iodide synergism for carbon steel in 1 M HCl: Combined experimental and theoretical studies. ACS Omega, 8(31), 28314-28332. https://doi.org/10.1021/acsomega.3c02105