Colchicine–protein interactions revealed by transient absorption spectroscopy after in situ photoisomerization to lumicolchicines

Irradiation of colchicine (COL) inside serum albumins (SAs) at 350 nm, results in an efficient isomerization to β- and γ-lumicolchicines (LCs). Laser flash photolysis of pre-irradiated COL/SA complexes leads to detection of long-lived LC-derived triplet excited states (λmax = 370 and 600 nm, τT > 10 μs).