Syntheses and Preliminary Study on the DNA-Binding Property of Nicotinoyl Aspartic Acid Dipeptide and Tetrapeptide

Nicotinic acid and niacinamide are used in a variety of therapeutic application as important components of the co-factors, nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate. Decreasing the adverse effects will improve the stability and absorption of nicotinic acid. Nicotinic acid aspartic acid dipeptide and tetrapeptide were synthesized via Fmoc solid-phase synthesis, purified via reversed-phase high performance liquid chromatography and characterized via proton and C-13 nuclear magnetic resonance and electrospray ionization mass spectrometry to change the property of nicotinic acid for promoting application of niacin derivatives. The interactions of nicotinic acid and nicotinoyl aspartic acid derivatives with calf thymus DNA were investigated by ultraviolet-visible absorption and fluorescence spectroscopy. The hypochromicity in ultraviolet spectra of DNA with increasing of nicotinic acid and derivatives concentration was observed. The fluorescence quenching of nicotinic acid and derivatives to ethidium bromide-DNA was mixture mode according to the Stern-Volmer equation. The results indicated that the interaction modes of nicotinic acid and nicotinoyl derivatives with calf thymus DNA were mixed mode of electrostatic repulsion and embed interaction, and the interaction of derivatives with calf thymus DNA was weakened by the carboxyl number of aspartic acids. Bioavailability and adverse event potential of the synthesized nicotinoyl aspartic acid di and tetrapeptides required to be evaluated.