Author(s)

Celine Kekwi Ngwang¹, Mireille Sylviane Dongmo Nguepi², Jean Hubert Nono³, Marius Belmondo Tincho², Mirabel Akongwi¹, Domiriane Ornela Madjougne Foudjo⁴, Darline Dize⁴, Diana Sandra Wendji Monkam⁴, David Woutouoba Ntieche⁴, Alvine Kengne⁴, Felicite Majoumo-Mbe^1*

¹Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon.
²Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon.
³Department of Chemical and Biological Engineering, National Higher Polytechnic Institute, University of Bamenda, Bamenda, Cameroon.
⁴Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon.

Zn(II) complexes of three heteroaryl Schiff bases L¹, HL² and L³ of general formula [ZnL¹Cl₂]∙2H₂O (1), [ZnL²Cl]∙H₂O (2), [ZnL³Cl₂]∙H₂O (3) [L¹ = 1-(quinolin-2-yl)-N-(quinolin-8-yl)methanimine, HL² = 2-((quinolin-8-ylimino)methyl)quinolin-8-ol, L³ = N-(pyridin-2-ylmethyl)-1-(quinolin-2-yl)methanimine] have been synthesised. Based on spectroscopic analyses, five-coordinate geometries were proposed where L¹ and L³ coordinated through the azomethine N and the two quinolines N as neutral NNN-donor modes, while HL² coordinated through the azomethine N, the two quinolines N and the O atom of the OH group as deprotonated with NNNO-donor mode. DFT calculations were used to investigate the electronic properties of the ligands and complexes, and their optimised structures were generated. Complexation and the presence of the OH group enhanced the activity against cercariae of Schistosoma mansoni while L¹ with fused benzene backbone and its complex were inactive compared to L³ with CH₂ backbone from 2-picolylamine derivative. Molecular docking studies revealed that the active compounds displayed higher binding affinity to the active sites of SmCE2a, SER, SmTGR, and SmPNP, with binding energies ranging from −6.1 to −10.1 kcal/mol, indicating that the ligands (HL²), L³ and complex (2) can be potential inhibitors of the four main target proteins of S. mansoni. In silico pharmacokinetics properties of HL², L³ and Zn(II) complex (2) agree with the four drug likeness rules (Lipinski, Ghose, Veber, and Egan rules) and these derivatives can be considered as potential lead candidates for an antischistosomal therapeutic development. Furthermore, the active ligands and complex showed a good bioavailability score of 0.55.

Zn(II) Complexes, Heteroaryl Schiff Bases, DFT Studies, In Vitro and in Silico Cercaricidal Potential, Pharmacokinetics Prediction

Ngwang, C.K., Nguepi, M.S.D., Nono, J.H., Tincho, M.B., Akongwi, M., Foudjo, D.O.M., Dize, D., Monkam, D.S.W., Ntieche, D.W., Kengne, A. and Majou-mo-Mbe, F.(2026) In Vitro Antischistosomal Potentials of 1-(quinolin-2-yl)-N-(quinolin-8-yl)methanimine, 2-((quinolin-8-ylimino)methyl)quinolin-8-ol and N-(pyridin-2-ylmethyl)-1-(quinolin-2-yl)methanimine] Heteroaryl Schiff Bases and Their Zn(II) Complexes: Synthesis, Characterisation, Density Functional Theory Studies, Molecular Docking and in Silico Pharmacokinetics Properties. Open Journal of Inorganic Chemistry, 16, 17-54. doi: 10.4236/ojic.2026.162002.