Benzo[a]acridinylmethyl esters as pH sensitive fluorescent photoactive precursors: synthesis, photophysical, photochemical and biological applications

newsworthy class of carboxylate esters based on the (benzo[a]acridin-12-yl) methyl (BAM) chromophore has been shown to perform dual functions as a pH sensitive fluorescent probe and a phototrigger for acids. The photophysical properties of all the BAM ester conjugates were investigated and found to be highly sensitive to solvent polarity, H-bonding capability and pH of the environment. On irradiation using UV light (>= 410 nm), BAM ester conjugates underwent heterolytic cleavage of C-O bonds resulting in efficient release of carboxylic and amino acids. Interestingly, the newly synthesized BAM chromophore was also explored for the construction of a drug delivery system (DDS). In the current DDS, the BAM chromophore plays two important roles: (i) a fluorophore for cell imaging and (ii) a phototrigger for the drug release. In vitro biological studies revealed that the newly developed BAM based DDS has a good biocompatibility, cellular uptake properties and efficient photoregulated anticancer drug release ability.