Structure elucidation, DNA binding specificity and antiproliferative proficiency of isolated compounds from Garcinia nervosa

Abstract

Garcinia nervosa is an abundant source of bioactive phytochemicals. The present paper deals with the isolation of a novel isoflavone 5,7-dihydroxy-3-(3′-hydroxy-4′,5′-dimethoxyphenyl)-6-methoxy-4H-chromen-4-one (1) along with a known compound DL-Allantoin (2) from the ethanolic extract of the leaves of Garcinia nervosa (Family: Guttiferae). Their structures were elucidated on the basis of chemical and physical evidences viz. elemental analysis, UV, FT-IR, 1H NMR, 13C NMR and mass spectral analysis. Single-crystal X-ray analysis was further used for the authentication of structure of both compounds (1 and 2). Interaction studies of compound (1) and (2) with ctDNA were studied by UV–Visible spectroscopy, fluorescence, KI quenching studies, competitive displacement assay and circular dichroism studies, which showed groove binding interaction (non-intercalation) of both the compounds 1 and 2 with ctDNA. However, compound 1 (K=3.9×104M−1) shows higher binding affinity to the ctDNA than compound 2 (K=1.44×104M−1). The molecular modeling results also illustrated that compound 1 strongly binds to groove of DNA by relative binding energy of docked structure −6.82kcal/mol. In addition the antiproliferative activity also showed high potential of compound 1 against MCF-7 and MDA-MB 231 cell line with IC50 value 8.44±3.5μM and 6.94±2.6μM, respectively.