Structure elucidation, DNA binding and molecular docking studies of natural compounds isolated from Crateva religiosa leaves

Abstract

Phytochemical investigations of the ethanolic extract of leaves of Crateva religiosa (Family: Capparaceae) resulted in the isolation of four compounds viz. (E)-ethyl-4-((3-(4-hydroxyphenyl)acryloyl)oxy)-2-methyl-5-oxotetrahydrofuran-2-carboxylate (Cg-1) named as Cratin, Cg-2, Cg-3, and Cg-4. Cg-1 has been reported for the first time from any natural source and has not been synthesized so far. Cg-2, Cg-3, and Cg-4 were also isolated first time from this plant source. Their structures were elucidated based on chemical and physical data viz. (elemental analysis, FT-IR, UV, 1H NMR, 13C NMR, and mass). Single crystal X-ray analysis was further used for the authentication of the structure of the isolated compounds in the case of Cg-1, including chemical modification of kaempferol (Cg-2) to Cg-2-Me, to get suitable crystals for X-ray diffraction study. The isolated novel compound Cg-1 and the methyl ether of kaempferol (Cg-2-Me) were screened for DNA binding studies with ct-DNA using UV-visible spectroscopy, fluorescence spectroscopy, and circular dichroism studies. Molecular docking was performed to understand the interaction between DNA and the compounds studied and showed groove binding interaction (non-intercalation).