Premium
A Highly Luminescent Tetrahydrocurcumin Ir III Complex with Remarkable Photoactivated Anticancer Activity
Author(s) -
Colombo Alessia,
Fontani Mattia,
Dragonetti Claudia,
Roberto Dominique,
Williams J. A. Gareth,
Scotto di Perrotolo Rossella,
Casagrande Francesca,
Barozzi Sara,
Polo Simona
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201901527
Subject(s) - curcumin , singlet oxygen , chemistry , iridium , phototoxicity , cytotoxicity , photodynamic therapy , photochemistry , luminescence , fluorescence , reactive oxygen species , combinatorial chemistry , nuclear chemistry , stereochemistry , oxygen , in vitro , organic chemistry , materials science , catalysis , biochemistry , physics , optoelectronics , quantum mechanics
Curcumin has chemopreventative properties against a variety of tumours, but has poor bioavailability. Here, two new bis‐cyclometallated iridium(III) complexes have been prepared, featuring the natural product curcumin (CUR) or its reduced form, tetrahydrocurcumin (THC), as bidentate, anionic O O ‐binding ligands. The iridium THC complex is highly luminescent in deoxygenated solution and efficiently generates singlet oxygen under aerated conditions, whereas in the CUR analogue, other non‐radiative decay pathways are competitive. The complexes are rapidly taken up by a variety of human tumour cell lines from solutions of micromolar concentration. They show negligible cytotoxicity in the absence of irradiation. When briefly irradiated with visible light, Ir‐THC becomes highly phototoxic, inducing rapid apoptosis within 2 h. The results show the high potential of such complexes as sensitizers in photodynamic therapy (PDT).