Benzothienoquinolines: New one-pot synthesis and fluorescence studies of their interaction with DNA and polynucleotides

Abstract

a b s t r a c tIn this work, we were able to obtain the benzothieno[3,2-b]quinoline 1 and benzothieno[2,3-c]quinoline 2 using a new one-pot procedure from the reaction of the commercially available 3-bromobenzo[b]thiophene-2-carbaldehyde with 2-aminophenylpinacolborane under Suzuki coupling conditions using a stereochemically hindered ligand, 2-(cyclohexylphosphane)biphenyl and Ba(OH) 2 ·8H 2 O as the base.Fluorescence properties of the benzothieno[3,2-b]quinoline 1 and the benzothieno[2,3-c]quinoline 2 were studied in solvents of different polarity. Both compounds exhibit a solvent sensitive emission, compound 1 being less fluorescent (˚F < 0.05) than compound 2 (0.04 ≤ ˚F ≤ 0.10).The interaction of these compounds with salmon sperm DNA and synthetic double-stranded heteropolynucleotides, poly(dA-dT)·(dA-dT) and poly(dG-dC)·(dG-dC), was studied using spectroscopic methods, allowing the determination of the intrinsic binding constants and binding site sizes. The interaction of both compounds is stronger with adenine-thymine (A-T) base pairs. Compound 1 is the most intercalative in salmon sperm DNA (47%) and polynucleotides (46-49% of intercalated molecules), while for compound 2, 41% is intercalated in salmon sperm DNA and only 8% in poly(dG-dC)·(dG-dC). Docking studies indicate that compound 1 interacts more strongly with DNA than compound 2, with a significant value of binding free energy in the case of intercalation. Minor groove binding is also very favourable and, probably, both mechanisms occur with a preponderance of intercalation in the case of compound 1.Overall, these results indicate that both benzothienoquinolines interact with nucleic acids by both intercalation and groove binding.

2,4,5-Triaminopyrimidines as blue fluorescent probes for cell viability monitoring: synthesis, photophysical properties, and microscopy applications

“…Further information on the binding preferences of the studied compounds with dsDNA can be obtained through molecular docking simulations using Autodock4 , 32 as used in other published works. 33,34 The crystallographic structures of a native dsDNA dodecamer (PDB ID ), proflavine (profl.) intercalated in a dsDNA hexamer (PDB ID 3 ft6) and a diamidine derivative (X8 V) groove-bound to a dsDNA dodecamer (PDB ID ) were used in docking studies by keeping only the polynucleotide structure.…”

Correlation between DNA/HSA-interactions and antimalarial activity of acridine derivatives: Proposing a possible mechanism of action

“…The potassium iodide assay is performed to evaluate the non-covalent binding mode between small molecules and DNA since it can promote dynamic quenching in fluorescent molecules if they are accessible to the iodide ion [34]. In this study, the comparison criteria used was the Stern-Volmer constant values in the presence and absence of ctDNA.…”

Synthesis of indolo- and benzothieno[3,2-c]quinolines via POCl3 mediated tandem cyclization of o-alkynylisocyanobenzenes derived from o-alkynyl-N-phenylformamides

“…12 In addition, benzothienoquinolines, sulfur analogs of the indoloquinolines, are found useful in various fields including material and medicinal sciences. 13 In contrast to vast reports on the synthesis of indolo[3,2- c ]quinolines, fewer works focused on the synthesis of benzothieno[3,2- c ]quinolines, 14 and in many cases appeared as substrate scopes rather than new methodology. 15 Although elegant approaches toward the synthesis of indolo[3,2- c ]quinolines and benzothieno[3,2- c ]quinolines have been documented, a general procedure which is applicable to access both scaffolds is still in need.…”