Molecular aspects on the specific interaction of homoisoflavonoids to DNA

• Published in: Journal of photochemistry and photobiology. B, Biology Biology, 2012-12, Vol.117, p.207-213
• Main Authors: Nafisi, Shohreh, Namdar, Roshanak
• Format: Article
• Language: English
• Subjects: 3-benzylidenechroman-4-ones; antioxidants; antiviral properties; aqueous solutions; biopolymers; DNA; DNA - chemistry; DNA - metabolism; flavonoids; Fourier transform infrared spectroscopy; FTIR; Homoisoflavonoids; Hydrogen-Ion Concentration; Isoflavones - chemical synthesis; Isoflavones - chemistry; Isoflavones - metabolism; Nucleic Acid Conformation; phosphates; photobiology; photochemistry; spectral analysis; Substrate Specificity; UV–Visible spectroscopy; Water - chemistry
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2012.09.016

► We model the binding of BMC, BPC, HBC and HBMC to DNA by using the spectroscopic methods. ► We investigate the effects of drug complexation on DNA stability and conformation. ► The affinity of homoisoflavonoids–DNA binding is in the order of BPC>BMC>HBMC>HBC. ► BMC, BPC, HBC and HBMC bind to DNA via a nonintercalation mode. ► No DNA conformational changes were observed uponhomoisoflavonoids complexation. Homoisoflavonoids (3-benzylidenechroman-4-ones) are related to flavonoids and occur as natural products and exhibit biological activity. These compounds have been reported to possess antioxidant, antifungal, hypocholesterolemic, antimutagenic and antiviral activities. This study was designed to examine the interactions of four synthetic homoisoflavonoids (BMC, BPC, HBC and HBMC) with calf-thymus DNA in aqueous solution at physiological conditions, using constant DNA concentration (6.25mM) and various homoisoflavonoids/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 homoisoflavonoids–DNA complexes in aqueous solution. Spectroscopic evidence showed major binding of homoisoflavonoids to DNA with overall binding constants of KBMC–DNA=9.37(±0.34)×103M−1, KBPC–DNA=1.8(±0.09)×104M−1, KHBC–DNA=1.3(±0.19)×103M−1 and KHBMC–DNA=4.7(±0.41)×103M−1. The affinity of homoisoflavonoids–DNA binding is in the order of BPC>BMC>HBMC>HBC. No biopolymer secondary structural changes were observed upon homoisoflavonoids interaction and DNA remains in the B-family structure in these complexes.