Synthesis of chrysin derivatives and their interaction with DNA

Using chrysin as a leading compound, intermediate 5,7-dihydroxy-6,8-bis (hydroxymethyl) flavone (1) was synthesized by hydroxymethylation. The intermediate reacted with different alcohols to afford 5,7-dihydroxy-6,8-bis(methoxymethyl) flavone (2), 6,8-bis(ethoxymethyl)-5,7-dihydroxyflavone (3), 6,8-bis-(butoxymethyl)-5,7-dihydroxyflavone (4), 6,8-bis(pentyloxymethyl)-5,7-dihydroxy flavone (5) and 6,8-bis-(ethoxymethyl)-5-hydroxy-7-methoxyflavone (6). These compounds were characterized by IR, ¹H NMR, ¹³C NMR and element analysis. The crystal structure of 6 was determined by X-ray crystal diffraction. The interaction of the derivatives with CT-DNA was studied by fluorescent spectroscopy. According to the Stern-Volmer equation, the quenching constants of the compounds 1-4 were measured, separately, they were k_q1=9.71×10³ L·mol^-1, k_q2=2.25×10⁴L·mol^-1, k_q3=1.03×10⁴L·mol^-1 and k_q4=7.96×10³ L·mol^-1. Compounds 1-4 showed higher binding affinity with DNA than chrysin did. The results provided the experimental basis for developing a more effective flavonoid and worthing further thoroughly study.