Molecular aspects on the specific interaction of homoisoflavonoids to DNA

New chroman-4-one/thiochroman-4-one derivatives as potential anticancer agents

The synthesis of 3-[3/4-(2-aryl-2-oxoethoxy)arylidene]chroman/thiochroman-4-one derivatives (1-34) and evaluation of their anticancer activities were aimed in this work. Final compounds were obtained in multistep synthesis reactions using phenol/thiophenol derivatives as starting materials. For anticancer activity evaluation, all compounds were offered to National Cancer Institute (NCI), USA and selected ones were tested against sixty human tumor cell lines derived from nine neoplastic diseases. The activity results were evaluated according to the drug screening protocol of the institute. Compounds containing thiochromanone skeleton exhibited higher anticancer activity.

Study on the interaction of homoisoflavonoids with RNA

Homoisoflavonoids (3-benzylidene-4-chromanones) are isomers of flavonoids and exhibit different biological activities because of hydroxyl groups attaching to different positions. This study is the first attempt to locate the binding sites of four synthetic homoisoflavonoids: (E)-3-(3,4-dihydroxybenzylidene)-7-methoxychroman-4-one (BMC), (E)-3-(3,4-dihydroxybenzylidene)-7-propoxychroman-4-one (BPC), (E)-3-(4-hydroxybenzylidene)-7-methoxychroman-4-one (HBMC) and (E) 3-(4-hydroxybenzylidene)-chroman-4-one (HBC) to RNA. The effect of the ligand complexation on RNA aggregation was investigated in aqueous solution at physiological conditions, using constant RNA concentration (6.25mM) and various ligand/polynucleotide (phosphate) ratios of 1/120, 1/80, 1/40, 1/20, 1/10 and 1/5. Fourier transform infrared (FTIR) and UV-Visible spectroscopic methods were used to determine the ligand binding modes, the binding constants, and the stability of ligand-RNA complexes in aqueous solution. Spectroscopic evidence showed external binding of homoisoflavonoids to RNA duplex with overall binding constants of KBMC-RNA = 1.06(± 0.09) × 10(4)M(-1), KBPC-RNA = 1.11(± 0.15) × 10(4)M (-1), KHBC-RNA = 3.82(± 0.09) × 10(3)M(-1) and KHBMC-RNA=5.82(± 0.04) × 10(3) M(-1). The affinity of homoisoflavonoid-RNA binding is in the order of BPC>BMC>HBMC>HBC. No biopolymer secondary structural changes were observed upon homoisoflavonoids interaction and RNA remains in the A-family structure in these complexes.