Synthesis and characterization of a manganese(II) complex containing N(sp²)₄-donor Schiff base ligand and interaction toward biomacromolecules

Abstract

In this work, an N₄-donor Schiff base ligand, N,N'-(propane-1,2-diyl)bis(1-phenyl-1-(pyridin-2-yl)methanimine) (PPPM) and its Mn(II) complex, [Mn(PPPM)(OAc)₂]·3H₂O (1), were prepared and identified by elemental analysis, FT-IR, ¹H NMR spectroscopy as well single-crystal X-ray diffraction. X-ray structure analysis of 1 revealed a distorted square-face bicapped trigonal prism geometry around manganese atom with MnN₄O₄ environment containing an N₄-donor PPPM and two O₂-donor acetato ligands. The ligand has a chiral center on carbon atom which leads to the formation of a racemic mixture of complex 1. In the crystal structure of complex, intermolecular hydrogen bonds form R₄⁴(8) hydrogen bond motifs. The ability of two optical isomers of PPPM ligand and manganese complex to interact with 10 selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II, B-DNA) was investigated by docking studies. These studies revealed that PPPM^R,S and 1^R,S isomers can bind to these molecules better than doxorubicin (except B-DNA).

Keywords:

• Manganese(II) complex
• docking study
• biomacromolecule
• Schiff base
• crystal structure

Acknowledgements

MD and MK thank Tereza Václavů from the Institute of Physics for measurement of the data set of complex 1. The crystallographic part was supported by the project 18-10504S of the Czech Science Foundation and used instruments of the CzechNanoLab Research Infrastructure supported by MEYS CR (LM2018110). We would like to acknowledge Dr. Keyvan Moeini for CSD studies and the FAIRE (Frank H. Allen International Research and Education Programme) award of the Cambridge Structural Database, for supplying the access to the CSD softwares package.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The crystallographic part was supported by the project 18-10504S of the Czech Science Foundation using instruments of the ASTRA laboratory established within the Operation Program Prague Competitiveness – project CZ.2.16/3.1.00/24510.