title: Ferrocenyl-L-amino acid copper(II) complexes showing remarkable photo-induced anticancer activity in visible light.
abstract: Ferrocene-conjugated copper(ii) complexes [Cu(Fc-aa)(aip)](ClO4) () and [Cu(Fc-aa)(pyip)](ClO4) () of l-amino acid reduced Schiff bases (Fc-aa), 2-(9-anthryl)-1H-imidazo[4,5-f][1,10]phenanthroline (aip) and 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (pyip), where Fc-aa is ferrocenylmethyl-l-tyrosine (Fc-Tyr in , ), ferrocenylmethyl-l-tryptophan (Fc-Trp in , ) and ferrocenylmethyl-l-methionine (Fc-Met in , ), were prepared and characterized, and their photocytotoxicity was studied (Fc = ferrocenyl moiety). Phenyl analogues, viz. [Cu(Ph-Met)(aip)](ClO4) () and [Cu(Ph-Met)(pyip)](ClO4) (), were prepared and used as control compounds. The bis-imidazophenanthroline copper(ii) complexes, viz. [Cu(aip)2(NO3)](NO3) () and [Cu(pyip)2(NO3)](NO3) (), were also prepared and used as controls. Complexes having a redox inactive cooper(ii) center showed the Fc(+)-Fc redox couple at ∼0.5 V vs. SCE in DMF-0.1 mol [Bu(n)4N](ClO4). The copper(ii)-based d-d band was observed near 600 nm in DMF-Tris-HCl buffer (1 : 1 v/v). The ferrocenyl complexes showed low dark toxicity, but remarkably high photocytotoxicity in human cervical HeLa and human breast adenocarcinoma MCF-7 cancer cells giving an excellent photo-dynamic effect while their phenyl analogues were inactive. The photo-exposure caused significant morphological changes in the cancer cells when compared to the non-irradiated ones. The photophysical processes were rationalized from the theoretical studies. Fluorescence microscopic images showed and localizing predominantly in the endoplasmic reticulum (ER) of the cancer cells, thus minimizing any undesirable effects involving nuclear DNA.
authors: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India. arc@ipc.iisc.ernet.in.
authors: Tridib K
authors: TK
authors: Goswami
authors: Sudarshan
authors: S
authors: Gadadhar
authors: Babu
authors: B
authors: Balaji
authors: Bappaditya
authors: B
authors: Gole
authors: Anjali A
authors: AA
authors: Karande
authors: Akhil R
authors: AR
authors: Chakravarty
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects; D001692:Biological Transport; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects; D053837:DNA Cleavage; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005296:Ferrous Compounds / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects; D006367:HeLa Cells; D006801:Humans; D008027:Light; D061986:MCF-7 Cells; D008856:Microscopy, Fluorescence; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects
chemical_list: D000596:Amino Acids; D000970:Antineoplastic Agents; D005296:Ferrous Compounds; D009942:Organometallic Compounds; D003300:Copper