Synthesis of novel fluorescent 1,3,5-trisubstituted triazine derivatives and photophysical property evaluation of fluorophores and their BSA conjugates

Cyanuric chloride was allowed to react with N,N-diethylaniline to obtain 4-(4,6-dichloro-1,3,5-triazin-2-yl)-N,N-diethylaniline, which was converted into six novel 1,3,5-trisubstituted triazine derivatives on reaction with different amino acids. These compounds had UV absorption in the range 352 -379 nm, accompanied by intense single emission in the range 420-497 nm with fairly good quantum yield (0.106-0.383). The new compounds were characterized by FT-IR, H-1 NMR, C-13 NMR, mass spectral, and elemental analyses. These fluorophores were conjugated with protein bovine serum albumin through carbodiimide chemistry between the negatively charged carboxylate groups (-COO-) of the fluorophore and the surface terminated positively charged amino groups (-NH3+) of the protein. The interaction between functionalized amino acids with protein molecules was investigated using fluorescence spectroscopy showing fluorescence enhancement or quenching of the fluorophore after conjugation.