title: Iron(III) catecholates for cellular imaging and photocytotoxicity in red light.
abstract: Iron(III) complexes [Fe(L)(L')(NO3)]--in which L is phenyl-N,N-bis[(pyridin-2-yl)methyl]methanamine (1), (anthracen-9-yl)-N,N-bis[(pyridin-2-yl)methyl]methanamine (2), (pyreny-1-yl)-N,N-bis[(pyridin-2-yl)methyl]methanamine (3-5), and L' is catecholate (1-3), 4-tert-butyl catecholate (4), and 4-(2-aminoethyl)-benzene-1,2-diolate (5)--were synthesized and their photocytotoxic properties examined. The five electron-paramagnetic complexes displayed a Fe(III)/Fe(II) redox couple near -0.4 V versus a saturated calomel electrode (SCE) in DMF/0.1 M tetrabutylammonium perchlorate (TBAP). They showed unprecedented photocytotoxicity in red light (600-720 nm) to give IC50≈15 μM in various cell lines by means of apoptosis to generate reactive oxygen species. They were ingested in the nucleus of HeLa and HaCaT cells in 4 h, thereby interacting favorably with calf thymus (ct)-DNA and photocleaving pUC19 DNA in red light of 785 nm to form hydroxyl radicals.
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012 (India), Fax: (+91) 802360068.
authors.forename: Uttara
authors.initials: U
authors.lastname: Basu
authors.forename: Ila
authors.initials: I
authors.lastname: Pant
authors.forename: Imran
authors.initials: I
authors.lastname: Khan
authors.forename: Akhtar
authors.initials: A
authors.lastname: Hussain
authors.forename: Paturu
authors.initials: P
authors.lastname: Kondaiah
authors.forename: Akhil R
authors.initials: AR
authors.lastname: Chakravarty
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002396:Catechols / Q000737:chemistry*; D002417:Cattle; D003116:Color; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000187:drug effects / Q000528:radiation effects*; D053837:DNA Cleavage; D005296:Ferrous Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D008027:Light; D008958:Models, Molecular; D057054:Molecular Imaging / Q000379:methods*; D015394:Molecular Structure; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D010957:Plasmids / Q000737:chemistry / Q000187:drug effects / Q000528:radiation effects; D011789:Quantum Theory; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D002396:Catechols; D005296:Ferrous Compounds; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D004247:DNA
keywords: DNA cleavage; apoptosis; bioinorganic chemistry; iron; photocytotoxicity