ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Unraveling the structure of Ni(II)–alizarin red S complex and its potential in antibacterial treatment: synthesis, characterization, and computational study approach

Hasan Muhtar, Damar Nurwahyu Bima, and Adi Darmawan

Department of Chemistry, Diponegoro University, Tembalang, Semarang, Indonesia

E-mail: adidarmawan@live.undip.ac.id

Received: 18 June 2023  Accepted: 21 September 2023

Abstract:

Nickel (II)–alizarin red S (Ni–ARS) complexes were synthesized using different mole ratios and pH. This study aims to analyze the effect of mole ratio and pH on the resulting complex structure and to determine the relationship between the geometric stability of the complex structure and its antibacterial ability using molecular docking studies. The variation in moles (1:2 and 1:3) did not affect the type or structure of the complex produced, but variations in pH affected the type of complex obtained. The dimer complex was obtained at pH 7 and 8, while the monomer complex was obtained at pH 6. ARS ligand complexation occurred in the carbonyl and hydroxyl (peri-hydroxy carbonyl) groups. DFT studies show that monomeric complexes are more stable than dimeric complexes while confirming a higher yield of monomeric complexes than dimeric complexes. Although DFT calculations show that monomer complexes are more stable than dimers, molecular docking showed antibacterial activity of E. coli and S. aureus from dimer complexes > monomer complexes > ARS. This study concluded that geometric stability is not always directly proportional to its bioactivity ability.

Keywords: Alizarin red S; Dimeric complex; Monomeric complex; DFT; Molecular docking

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03109-3

Chemical Papers 78 (1) 547–563 (2024)