Spectroscopic Exploration of Mode of Binding of ctDNA with 3-Hydroxyflavone: A Contrast to the Mode of Binding with Flavonoids Having Additional Hydroxyl Groups

Abstract

Binding interaction of 3-hydroxyflavone (3HF), a bioactive flavonoid, with calf-thymus DNA (ctDNA) has been explored exploiting various experimental techniques. The dual fluorescence of 3HF resulting from the excited state intramolecular proton transfer (ESIPT) is modified remarkably upon binding with the biomacromolecule. The determined binding constant, fluorescence quenching experiment, circular dichroism (CD) study, comparative binding study with the known intercalative binder ethidium bromide and thermometric experiment relating to the helix melting of ctDNA confirm the groove binding of 3HF with the DNA. This is in contrast to two other members of the flavonoid group, namely, fisetin and quercetin, where the bindings are established to be intercalative. The structural difference of 3HF from the other two probes with respect to the absence/presence of the additional hydroxyl groups is ascribed to be responsible for the difference in the mode of binding.

Studying non-covalent drug–DNA interactions

“…To study the interaction of small molecules with DNA, T m of the DNA solution in the absence and presence of small molecules or drugs are recorded. Small molecules that bind to DNA via an intercalation mode lead to stabilisation of DNA and results in an increase in the T m of DNA by about 5-8°C [18]. However, groove binding molecules do not alter the melting temperature of DNA duplex to such an extent [19].…”

“…3-Hydroxyflavone (3HF) is a groove binding molecule that does not increase the T m of DNA while Quercitin (Q) follows intercalating mode and increases T m significantly. Figure is reproduced with permission from the manuscript of Jana et al [18].…”

Comprehensive exploration of the anticancer activities of procaine and its binding with calf thymus DNA: a multi spectroscopic and molecular modelling study

“…6 Furthermore, it was found to improve the therapeutic index of chemotherapy agent cisplatin around two-fold. 7 Procaine in a small dose of 2 mM has shown cytotoxicity to leukemic cells with further enhancement in the cytotoxicity at 42 C. 8 The most noticeable role of procaine related to the cancer chemotherapy is the demethylation of DNA.…”

Intercalation binding of food antioxidant butylated hydroxyanisole to calf thymus DNA

“…In recent years, some food additives such as dyes [16][17][18] and sweeteners [19,20] bound to DNA were also investigated. These studies are valuable for exploring the structural and functional features of the biomacromolecule to decipher its biophysical processes [21], and can provide useful information for further understanding the toxicology of the chemicals. Kashanian et al reported that BHA interacted with DNA via an intercalative mode [22].…”