Cibacron Blue 3G-A is the predominant substance utilized in affinity chromatography to purify enzymes with a dinucleotide fold such as lactate dehydrogenase (LDH). Part of Cibacron Blue 3G-A is the anthraquinone core which has natural bioactivity proven by the application of different anthraquinone derivatives into various fields. The scope of our research is to synthesize a small library of anthraquinone derivatives to potentially be used in protein purification as a replacement for the expensive Cibacron Blue 3G-A. In reducing the size of the ligand, we are sacrificing the number of functional groups to search for the crucial interactions necessary to drive binding. Besides the primary aim, the additional challenge of making the synthetic pathway be shorter was solved by begin with 1-aminoanthraquinone or 1,4-aminoanthraquinone. The first reaction is a monotosylation as an attempt to control the orientation of intercalation with LDH. Following the purification of our monotosylated 1,4-aminoanthraquinone two separate reactions will be done: (1) alkylation reaction of the free amine, or (2) formation of a diazonium salt and subsequent nucleophilic addition of various anilines. Biological evaluation of the derivatives will be compared by bind constants obtained by enzyme kinetics measured via fluorescence quenching. There are six derivatives synthesized with various R-groups we aim to evaluate to gain insight on the electrostatic and hydrophobic binding.
