Synthesis, Two-Photon Absorption, and Cellular Imaging of Two Curcumin Derivatives

Two curcumin derivatives, 1,7-bis(4-bromoethyloxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (1) and 1,7-bis(4-bromobutyloxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (2), have been conveniently synthesized and their structures characterized by 1H NMR and mass spectra, and single crystal X-ray diffraction measurements. Single-photon and two-photon fluorescence properties have been studied. The calculated two-photon absorption cross-sections for both compounds by quantum chemical method are as high as 358 and 326 GM, respectively. Two-photon fluorescent imaging of MCF-7 cells labeled with the compound 1 indicates its potential application as a biological fluorescent probe.