Catechin, a yellow colored molecule obtained from the wood of Acacia catechu was analyzed for its interaction with synthetic DNA duplexes using spectroscopic analysis. UV-Visible spectroscopic analysis revealed the non-intercalative binding mode. Fourier Transform Infrared spectroscopy (FTIR) analysis expose chemical shift indicated by various vibrational stretches and an increase in the intensity of base stacking was observed by Circular Dichroism (CD), respectively. This inference was further confirmed through nuclear staining technique and also in electrophoretic technique; the dye quenches the fluorescent intensity of ethidium bromide. The result of fluorescence spectroscopy was in concordance with the electrophoretic technique. In addition, the spectroscopic results were in accordance with the molecular docking studies of specific catechin compound from the catechu dye with CT-DNA. This kind of site specificity is a gain in the medicinal field as the drug can be DNA targeted for cancer therapeutics. The present work reveals that catechu dye has a noteworthy application in the field of medical bioscience. © 2016 © 2016 Taylor &amp; Francis Group, LLC.

George Priya Doss C

Department of Integrative Biology

School of Bio Sciences and Technology

Vellore Campus

Siva R

Department of Biotechnology

Hemachandran H

Anantharaman A

Priya R.R

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Interaction of Catechu Dye with DNA: Spectroscopic and In Silico Approach.

Nucleosides, Nucleotides and Nucleic Acids

Bixin and crocin are natural apocarotenoids utilized as food colorants and additives in food industries worldwide. For safety assessment, it is necessary to understand the biological interaction of food colorants. In our present study, we report the interaction of two apocarotenoids with bovine serum albumin (BSA) at physiological pH using spectroscopic techniques and in silico tools. The binding constant and the mode of binding sites have been studied. The enthalpic and entropic contribution to the intermolecular binding event was analyzed and it was found that the contribution of hydrogen bonding and hydrophobic interactions was dominant. The adverse temperature dependence in the unusual static quenching is found to b. reasonable consequence of the large activation energy requirement in the binding process, which is required to overcome the fundamental block and i. direct result of the unique microstructure of the binding sites. To confirm the experimental analysis, we investigated the binding patterns using different in silico tools. combination of molecular docking, molecular dynamics, and toxicity analysis was performed, and the obtained results revealed that both the apocarotenoids had high binding affinity wit. binding energy of −5.44 and −5.93 kcal/mol for bixin and crocin, respectively, with no toxic effects and are in accordance with our experimental analysis. The results directly revealed the flexibility of the protein toward bixin and crocin which ha. great impact on the interaction. Thus bixin and crocin can guardedly be used as food colorants in food industries. © 2017 Informa UK Limited, trading as Taylor &amp; Francis Group.

Journal of Biomolecular Structure and Dynamics

Structural insights into the binding mode and conformational changes of BSA induced by bixin and crocin

The interaction of food colorant norbixin with calf thymus DNA (CTDNA) was investigated through UV-Visible spectroscopy, Fourier Transform Infrared (FTIR), Circular Dichroism (CD), Nuclear Magnetic Resonance (NMR), DNA melting studies, electrophoretic analysis, histological staining technique and molecular docking studies. The results indicated that norbixin interacted with CTDNA by partial intercalation mode. The binding constant (K) of norbixin with CTDNA was calculated to be 5.08 × 105 Mol-1 L. FTIR and CD studies were coupled with 1H NMR spectra revealed that norbixin intercalates partially and binds to the groove's, phosphate group, deoxyribose sugar of DNA and also induces conformational transition of B-form to A-form DNA. Agarose gel electrophoretic and histological staining technique results further prove that, norbixin specifically binds to the DNA in the cell. Moreover, molecular docking studies on the specific binding of norbixin with CTDNA have exhibited lowest conformation energy score of -3.2. Therefore, this food colorant has the ability to interact with DNA and it could emerge as a promising class of natural DNA targeted therapeutic. © 2015 Elsevier B.V. All rights reserved.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Studies on interaction of norbixin with DNA: Multispectroscopic and in silico analysis

A mononuclear copper(II) <a href="https://www.sciencedirect.com/topics/chemistry/salicylate">salicylate</a> with bulky substitution [Cu(DTBSA)2(2,2′-bpy)](dmf) (1) (DTBSA&nbsp;=&nbsp;3,5-di-tert-butyl <a href="https://www.sciencedirect.com/topics/chemistry/salicylic-acid">salicylic acid</a>, 2,2′-bpy&nbsp;=&nbsp;2,2′-bipyridyl) has been synthesized and characterized with the aid of <a href="https://www.sciencedirect.com/topics/chemistry/elemental-analysis">elemental analysis</a> and infrared, ultraviolet, fluorescence and <a href="https://www.sciencedirect.com/topics/chemistry/epr-spectroscopy">electron paramagnetic resonance</a> spectroscopic techniques. The molecular structure of compound 1 was analyzed by <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/single-crystal-x-ray-diffraction">single-crystal X-ray diffraction</a>, it shows monomeric copper atom coordinating to two salicylate moieties along with one bipridyl ligand. Hydrogen bonding interactions and π–π aromatic stacking interactions led to the formation of 1D polymeric structure. The <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/dna-binding">DNA binding</a> studies of compound 1 against CT-DNA (calf thymus) investigated by absorption, emission and <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/docking-molecular">molecular docking</a> methods. The results from <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/binding-affinity">binding constant</a> (Kb), linear Stern–Volmer quenching constant (Ksv) and molecular docking have shown that the copper(II) salicylate has better binding activity.

Inorganic Chemistry Communications

Synthesis, crystal structure, DNA binding and molecular docking studies on new copper(II) salicylate [Cu(DTBSA)2(2,2′-bpy)](dmf)

Anthraquinones consist of several hundreds of derivatives that differ in the nature and positions of substituent groups which are known to have several biological activities including antitumor properties. Interaction of molecules with DNA persists to be an extremely vital parameter while endeavouring to formulate therapeutics. In this study, few anthraquinone derivatives such as 1,2-dihydroxyanthraquinone (alizarin), 1,4-dihydroxyanthraquinone (quinizarin), 1,8-dihydroxyanthraquinone (danthron), 1,2,4-trihydroxyanthraquinone (purpurin), 1,4-diaminoanthraquinone, and 1-methylaminoanthraquinone were analyzed for its possible interaction with calf-thymus DNA through spectroscopy and in silico analysis. Our UV spectroscopic results indicate that all selected anthraquinones interact with DNA probably by external binding. Molar extinction coefficient has been calculated for chosen six anthraquinones. FT-IR results suggest that significant shifts of peaks as well as disappearance of certain characteristic peaks were indicators of the plausible interaction going on due to dye-DNA adduct formation. Among the six dyes used, purpurin showed better results and indicates the relatively strong binding affinity with DNA. Our molecular modeling results also show that purpurin has comparatively higher DNA interaction with a score of -6.18 compared with the ethidium bromide of -5.02 and intercalate the DNA. © 2013 Springer Science+Business Media New York.

Applied Biochemistry and Biotechnology

Spectroscopic and In Silico Evaluation of Interaction of DNA with Six Anthraquinone Derivatives

The interactions between the molecules and DNA shape up an avenue for DNA targeted therapeutics. For the first time, brazilin, a major component of Caesalpinia sappan L., has been investigated for its interaction with natural and synthetic DNA. Detailed analyses of the binding property of brazilin dye with DNA by UV-vis, FTIR and Circular Dichroism were carried out. In addition, in silico studies have been conducted via tools of energy minimization and ligand optimization using Yasara and Argus Lab softwares along with the molecular docking server integrating Auto Dock, Mavin and Mopac. Results show that brazilin dye has commendable proficiency in being moulded as a binder with DNA. The specificity of the dye to stain nuclei in tissue sections positively indicates its interaction with nucleic acid. As the intracellular target for the majority of anticancer and antibiotic drugs is DNA, the study on the interaction between molecules like brazilin and DNA has great significance and implications in several biological applications. © 2013 International Association of Scientists in the Interdisciplinary Areas and Springer-Verlag Berlin Heidelberg.

Interdisciplinary Sciences: Computational Life Sciences

Interaction of plant pigment brazilin with synthetic and natural DNA: Spectroscopic and in silico perspective

Plant dyes have been in use for coloring and varied purposes since prehistoric times. A red dye found in the roots of plants belonging to genus Morinda is a well recognized coloring ingredient. The dye fraction obtained from the methanolic extract of the roots of Morinda tinctoria was explored for its role in attenuating damages caused by H 2O 2-induced oxidative stress. The antioxidant potential of the dye fraction was assessed through DPPH radical scavenging, deoxyribose degradation and inhibition of lipid peroxidation in mice liver. It was subsequently screened for its efficiency in extenuating damage incurred to biomembrane (using erythrocytes and their ghost membranes) and macromolecules (pBR322 DNA, lipids and proteins) from exposure to hydrogen peroxide. In addition, the non-toxic nature of the dye was supported by the histological evaluation conducted on the tissue sections from the major organs of Swiss Albino mice as well as effect on Hep3B cell line (human hepatic carcinoma). The LC-MS confirms the dye fraction to be morindone. Our study strongly suggests that morindone present in the root extracts of M. tinctoria, in addition to being a colorant, definitely holds promise in the pharmaceutical industry. © 2012 Elsevier Ltd.

Journal	Nucleosides, Nucleotides and Nucleic Acids
Publisher	Informa UK Limited
ISSN	1525-7770
Open Access	No