Linker-Free Near-IR Aza-BODIPY-Glutamine Conjugates Through Boron Functionalization
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim A series of linker-free aza-BODIPY-glutamine conjugates were synthesized and investigated, both experimentally and computationally. The structures of the aza-BODIPYs were confirmed spectroscopically, and in the case of 3a an X-ray structure was obtained. All aza-BODIPYs show intense absorption bands between 642–667 nm and fluorescence emissions between 691–703 nm. The fluorescence quantum yields of the 2,6-unsubstituted compounds 1a–4a were found to be Φf ≈ 0.2 in chloroform, while those of the corresponding 2,6-dibrominated derivatives 1b–4b were less than 0.01. The cytotoxicity and cellular uptake of all aza-BODIPYs were investigated in human carcinoma HEp2 cells. The most cytotoxic aza-BODIPYs were found to be 3a and 3b, due to the presence of the cyclic N,O-bidentate amino acid ring, rather than the presence of the 2,6-bromine atoms. The results show that the mode of glutamine conjugation to the aza-BODIPY determines the stability and cytotoxicity of the conjugates.
Publication Source (Journal or Book title)
European Journal of Organic Chemistry
Wang, M., Zhang, G., Kaufman, N., Bobadova-Parvanova, P., Fronczek, F., Smith, K., & Vicente, M. (2020). Linker-Free Near-IR Aza-BODIPY-Glutamine Conjugates Through Boron Functionalization. European Journal of Organic Chemistry, 2020 (8), 971-977. https://doi.org/10.1002/ejoc.201901772