Stacking of antiaromatic molecules leads to enhanced stability and higher conductivity due to reversed antiarotmaticity. It has been shown that cyclophenes consisting of antiaromatic Ni(II) norrcorrole subunits have a vertical current-density flux between the two metal ions. The Ni(II) meso- substituted dibenzotetraaza[14]annulene complex fulfills the Hückel rule for being antiaromatic. Upon increasing the temperature above 13 K, the effective magnetic moment of solid state Ni(II) meso-substituted dibenzotetraaza[14]annulene changes from being diamagnet to paramagnetic. A suggested explanation for this is that there might be weak interaction between the Ni atoms. In this study the possibility of the existence of vertical current-density flux between the two metal ions in the Ni(II) meso-substituted dibenzotetraaza[14]annulene is investigated. In addition, the effect of the Ni and N atoms in Ni(II) 1,5,9,13-tetraaza[16]annulene was studied by replacing Ni and Zn and N with O. Electronic motion in molecules that are under the influence of a magnetic field is investigated computationally, since at present there is no routine experimental method for doing that. TURBOMOLE, the Gauge-including Magnetically Induced Currents method and Paraview were employed in this study for structure optimization of the molecules, calculation of current-density flux and current strength in the molecules and visualisation of the current-density pathways respectively. The results of this study does not show any current transport between the subunits in the Ni(II) meso-substituted dibenzotetraaza[14]annulene complex. Both the Ni(II) 1,5,9,13-tetraaza[16]annulene and the Zn(II) 1,5,9,13-tetraaza[16]annulene are aromatic but they were not stacked due to their distorted structure. The (2Z,7Z,10Z,14Z)-1,9-dioxa-5,13-diazacyclohexadeca-2,7,10,14-tetraene-5,13-diide complexes with either Zn(II) or Ni(II) were both non-aromatic as well as the Ni(II) (2Z,7Z,10Z,14Z)-1,9-dioxa-5,13-diazacyclohexadeca-2,7,10,14-tetraene-5,13-diide dimer.

A series of novel thiazolidine-4-one derivatives was synthesized by reacting 1,4disubstituted hydrazine carbothioamides with diethyl azodicarboxylate. The structures were confirmed by spectroscopic data as well as single-crystal X-ray analyses. The antiproliferative activity of the synthesized compounds was investigated against four human cancer cell lines using an MTT assay. Compounds 5d, 5e, and 5f revealed the most potent antiproliferative activity with GI50 values ranging from 0.70 mM to 1.20 mM, compared to doxorubicin GI50 value = 1.10 mM. Compounds 5d, 5e, and 5f were further investigated for their inhibitory activities against CDK2 and EGFR as potential targets for their molecular mechanism. Compounds 5e and 5f have showed potent inhibitory activity to CDK2 enzyme with IC50 values of 18 and 14 nM, which is more potent than the reference dinaciclib (IC50 = 20 nM). Moreover, compounds 5e and 5f were the most potent EGFR inhibitors, with IC50 values of 93 and 87 nM, respectively, compared to the reference erlotinib (IC50 = 70 nM). In addition, the most potent derivatives were tested for their apoptotic activity against caspases 3, 8, and 9, and the results showed that compounds 5d, 5e, and 5f revealed a greater increase in active caspases 3,8 and 9 than doxorubicin. Also, compounds 5d, 5e, and 5f elevated cytochrome C levels in the MCF-7 human breast cancer cell line by about 15.5, 15.8, and 16.5 times, respectively. Finally, a molecular docking study was performed to investigate the binding sites of these compounds within the active sites of CDK2 and EGFR targets, and the results confirmed that the most potent CDK2 and EGFR inhibitor 5h also have showed the highest docking (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Herein, we report the synthesis of 5,12-dihydropyrazino[2,3-c:5,6-c ' ]difuro[2,3-c:4,5-c ']-diquinoline-6,14(5H,12H)diones, 2-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-1,4-diphenyl- butane-1,4-diones and 4-(benzo-[d]oxazol-2-yl)-3-hydroxy-1H-[4,5]oxazolo[3,2-a]pyridine-1-one. The new candidates were synthesized and identified by different spectroscopic techniques, and X-ray crystallography.