Organic-inorganic hybrid salt and mixed ligand Cr(III) complexes containing the natural flavonoid chrysin: Synthesis, characterization, computational, and biological studies

Mamaru Bitew Alem; Tegene Desalegn; Tadewos Damena; Enyew Alemayehu Bayle; Moses O Koobotse; Kennedy J Ngwira; Japheth O Ombito; Matshediso Zachariah; Taye B Demissie

doi:10.3389/fchem.2023.1173604

Organic-inorganic hybrid salt and mixed ligand Cr(III) complexes containing the natural flavonoid chrysin: Synthesis, characterization, computational, and biological studies

Front Chem. 2023 Apr 12:11:1173604. doi: 10.3389/fchem.2023.1173604. eCollection 2023.

Authors

Mamaru Bitew Alem¹, Tegene Desalegn¹, Tadewos Damena², Enyew Alemayehu Bayle^{3

4}, Moses O Koobotse⁵, Kennedy J Ngwira⁶, Japheth O Ombito⁷, Matshediso Zachariah⁵, Taye B Demissie⁷

Affiliations

¹ Department of Applied Chemistry, Adama Science and Technology University, Adama, Ethiopia.
² Department of Chemistry, Wachemo University, Hossana, Ethiopia.
³ Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan.
⁴ Department of Chemistry, Debre Markos University, Debre Markos, Ethiopia.
⁵ School of Allied Health Professions, University of Botswana, Gaborone, Botswana.
⁶ Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa.
⁷ Department of Chemistry, University of Botswana, Gaborone, Botswana.

Abstract

Organic-inorganic hybrid salt and mixed ligand Cr(III) complexes (Cr1 and Cr2) containing the natural flavonoid chrysin were synthesized. The metal complexes were characterized using UV-Vis, Fourier-transform infrared, MS, SEM-EDX, XRD, and molar conductance measurements. Based on experimental and DFT/TD-DFT calculations, octahedral geometries for the synthesized complexes were suggested. The powder XRD analysis confirms that the synthesized complexes were polycrystalline, with orthorhombic and monoclinic crystal systems having average crystallite sizes of 21.453 and 19.600 nm, percent crystallinities of 51% and 31.37%, and dislocation densities of 2.324 × 10^-3 and 2.603 × 10^-3 nm^-2 for Cr1 and Cr2, respectively. The complexes were subjected to cytotoxicity, antibacterial, and antioxidant studies. The in vitro biological studies were supported with quantum chemical and molecular docking computational studies. Cr1 showed significant cytotoxicity to the MCF-7 cell line, with an IC₅₀ value of 8.08 μM compared to 30.85 μM for Cr2 and 18.62 μM for cisplatin. Cr2 showed better antibacterial activity than Cr1. The higher E _HOMO (-5.959 eV) and dipole moment (10.838 Debye) values of Cr2 obtained from the quantum chemical calculations support the observed in vitro antibacterial activities. The overall results indicated that Cr1 is a promising cytotoxic drug candidate.

Keywords: Cr(III) complex; MCF-7; chrysin; cytotoxicity; molecular docking; organic–inorganic hybrid salt.