Picoline based fluorescence ‘turn-on’ chemosensor for zinc(II) ion recognition, cell imaging and cytotoxicity study: Synthesis, crystal structure, spectroscopy and DFT

• Published in: Polyhedron Vol. 192; pp. 114815 - 114827
• Main Authors: Jana, Abhimanyu, Aher, Abhishek, Brandao, Paula, Ali, Syed Samim, Samanta, Sandip Kumar, Mondal, Gopinath, Bera, Pradip, Santra, Ananyakumari, Manna, Sunil Kumar, Mahapatra, Ajit Kumar, Bera, Pulakesh
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.12.2020; Elsevier
• Subjects: Antitumor activity; Cell imaging; Chemistry; Chemistry, Inorganic & Nuclear; Crystallography; Cytotoxicity; Physical Sciences; Picoline-phenol; Science & Technology; Small molecule; Zinc sensor; Cell imaging; Picoline-phenol; Cytotoxicity; Antitumor activity; Small molecule; Zinc sensor; Crystallography; MOLECULE; COMPLEXES; SENSOR; AMINO-ACID; SIMPLE PYRAZOLINE; PYROPHOSPHATE; SCHIFF-BASE; ZN2+ ION; HG2+ IONS; PROBE
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2020.114815

A picoline based ‘turn-on’ chemosensor (L) and it’s zinc(II) complex, Zn(L)2 (1) have been synthesized and structurally characterized. The detection limit (0.36 µM) and association constant (log Kapp = 13.25) are evaluated by the fluorescence experiment. The probe shows reversibility in addition of dihydrogen phosphate (H2PO4−) ion to the 1. The probe has sufficient cell permeability and intracellular Zn(II) imaging property. Both L and 1 are innocuous against PBMC (peripheral blood mononuclear cells) but effective antitumor agents against U-937 cancer cells. [Display omitted] •Synthesis and structure of a highly selective and sensitive picoline based small molecule (Mol. Wt. 254).•A ‘turn on’ fluorescent probe with Zn(II) in HEPES buffer.•Excellent bleaching of fluorescence in H2PO4− to the Zn-complex.•Ligand has sufficient cell permeability and intracellular Zn(II) sensing property.•Compounds are innocuous against PBMC but effective antiproliferative against U-937 cancer cells. A new picoline based ligand, namely 2-hydroxy-5-methyl-3-[{(6-methylpyridin-2-yl)imino}methyl]benzaldehyde (L) and it’s zinc(II) complex, Zn(L)2 (1) have been synthesized and structurally characterized. The ligand (L) selectively interacts with Zn2+ ion in presence of series of cations in CH3CN-H2O (v/v 1:1) in 1 mM HEPES buffer (pH 7.2). The fluorescence intensity of L is significantly enhanced, and it is increased to 52 times on coordination with Zn(II) ion. The fluorescence intensity value of the L does not show any significant change in the pH range 5 to 9, while the extent of emission phenomenon with Zn(II) ions is observed in the said pH range. The detection limit (0.36 µM) and association constant (log Kapp = 13.25) are evaluated by the fluorescence emission experiment. The probe shows reversibility in addition of dihydrogen phosphate (H2PO4−) ion to the 1. Additionally, the ‘turn-on’ fluorescence probe has sufficient cell permeability and intracellular Zn(II) sensing property as envisaged from the microscopic imaging in HEK293T cells. Both L and ZnL2 (1) are innocuous against PBMC (peripheral blood mononuclear cells) but effective antitumor agents against U-937 cancer cells.