title: A novel chromo- and fluorogenic dual sensor for Mg(2+) and Zn(2+) with cell imaging possibilities and DFT studies.
abstract: A diformyl-p-cresol (DFC)-8-aminoquinoline based dual signaling probe was found to exhibit colorimetric and fluorogenic properties on selective binding towards Mg(2+) and Zn(2+). Turn-on fluorescent enhancements (FE) as high as 40 fold and 53 fold in 9 : 1 MeCN/water (v/v) at pH 7.2 in HEPES buffer for Mg(2+) and Zn(2+), respectively, were observed. The binding constants determined from the fluorescence titration data are: K = (1.52 ± 0.21) × 10(5) M(-1) and (9.34 ± 4.0) × 10(3) M(-2) at n = 1 and 0.5, for Mg(2+) and Zn(2+), respectively. The L : M binding ratios were also determined by Job's method, which support the above findings. This is further substantiated by HRMS analysis. Due to solubility in mixed organo-aqueous solvents as well as cell permeability it could be used for the in vitro/in vivo cell imaging of Mg(2+) and Zn(2+) ions with no or negligible cytotoxicity. This probe could be made selective towards Mg(2+) over Zn(2+) in the presence of TPEN, both under intra- and extracellular conditions and is superior to other Mg(2+) probes which suffer from selectivity of Mg(2+) over Ca(2+) or Zn(2+). Furthermore the dissociation constant (Kd = 6.60 μM) of the Mg(2+)-() complex is far lower than the so far reported Mg(2+) probes which fall in the mM range.
authors.affiliation: Department of Chemistry Jadavpur University, Kolkata 700 032, India. mali@chemistry.jdvu.ac.in.
authors.forename: Rabiul
authors.initials: R
authors.lastname: Alam
authors.forename: Tarun
authors.initials: T
authors.lastname: Mistri
authors.forename: Atul
authors.initials: A
authors.lastname: Katarkar
authors.forename: Keya
authors.initials: K
authors.lastname: Chaudhuri
authors.forename: Sushil Kumar
authors.initials: SK
authors.lastname: Mandal
authors.forename: Anisur Rahman
authors.initials: AR
authors.lastname: Khuda-Bukhsh
authors.forename: Kalyan K
authors.initials: KK
authors.lastname: Das
authors.forename: Mahammad
authors.initials: M
authors.lastname: Ali
mesh_terms: D000634:Aminoquinolines / Q000737:chemistry*; D002413:Cations, Divalent / Q000032:analysis; D003124:Colorimetry; D003408:Cresols / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D056945:Hep G2 Cells; D006801:Humans; D008274:Magnesium / Q000032:analysis; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D061848:Optical Imaging; D013050:Spectrometry, Fluorescence; D015032:Zinc / Q000032:analysis*
chemical_list: D000634:Aminoquinolines; D002413:Cations, Divalent; D003408:Cresols; D005456:Fluorescent Dyes; C032538:4-cresol; D008274:Magnesium; D015032:Zinc; C080436:8-aminoquinoline