Premium
Mitochondria‐Targeted Anticancer Activity of BODIPY‐Appended Iron(III) Catecholates in Red Light
Author(s) -
Garai Aditya,
Pant Ila,
Bhattacharyya Arnab,
Kondaiah Paturu,
Chakravarty Akhil R.
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201702166
Subject(s) - bodipy , singlet oxygen , chemistry , photochemistry , reactive oxygen species , hela , moiety , dichlorofluorescein , photodynamic therapy , fluorophore , fluorescence , stereochemistry , oxygen , biochemistry , cell , organic chemistry , physics , quantum mechanics
Iron(III) catecholates of dipicolylamine (dpa) bases having appended Benzyl (in bzdpa) or BODIPY (borondipyrromethene) moiety (in L 1 and L 2 ), viz. [Fe(Bzdpa)(cat)Cl] ( 1 ), [Fe(L 1 )(cat)Cl] ( 2 ) and [Fe(L 2 )(cat)Cl] ( 3 ), were prepared and characterized (H 2 cat=catechol). The iron(III) complexes with a ligand‐to‐metal charge transfer (LMCT) band within 600–800 nm were studied for their photocytotoxicity in visible (400–700 nm) and red (600–720 nm) light. Complex 2 with a BODIPY fluorophore in L 1 gave IC 50 values of 2.2±0.5 and 15.0±0.7 μM in visible and red light, respectively, in HeLa cells. Complex 3 with a diiodo‐BODIPY moiety showed excellent PDT activity giving respective IC 50 values of 0.8±0.2 and 12.6±1.1 μM. They are less toxic in dark (IC 50 : ≥85 μM). A similar activity was observed in MCF‐7 cancer cells. The BODIPY complexes showed significant mitochondrial localization. Annexin FITC assay showed apoptotic cell death involving reactive oxygen species (ROS). Photo‐generation of ROS was evidenced from dichlorofluorescein diacetate (DCFDA) assay. Mechanistic studies on DNA photocleavage reactions showed the presence of two types of ROS. Singlet oxygen formation from BODIPY was evidenced from the 1,3‐diphenylisobenzofuran (DPBF) experiments. Hydroxyl radical was generated on red light photo‐activation of the LMCT band within photodynamic therapy (PDT) spectral window.