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Related Experiment Video

Updated: Jun 12, 2026

Genome-wide Mapping of Drug-DNA Interactions in Cells with COSMIC (Crosslinking of Small Molecules to Isolate Chromatin)
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Beta-carboline alkaloids bind DNA.

Shohreh Nafisi1, Mahyar Bonsaii, Pegah Maali

  • 1Department of Chemistry, Azad University, Central Tehran Branch (IAUCTB), Tehran, Iran. s.nafisi@neu.edu

Journal of Photochemistry and Photobiology. B, Biology
|June 15, 2010
PubMed
Summary
This summary is machine-generated.

Five beta-carboline alkaloids from Peganum harmala bind to DNA, with harmine showing the strongest affinity. These interactions do not alter DNA structure, suggesting potential antitumor mechanisms.

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Area of Science:

  • Biochemistry
  • Molecular Biology
  • Pharmacology

Background:

  • Beta-carboline alkaloids from Peganum harmala exhibit promising antitumor activities.
  • Mechanistic studies suggest beta-carbolines inhibit DNA topoisomerases and DNA synthesis.
  • These compounds interact with DNA through groove binding and intercalation, inducing structural changes.

Purpose of the Study:

  • To investigate the interaction of five beta-carboline alkaloids (harmine, harmane, harmaline, harmalol, tryptoline) with calf-thymus DNA.
  • To determine the binding modes, binding constants, and stability of alkaloid-DNA complexes under physiological conditions.

Main Methods:

  • Utilized Fourier transform infrared (FTIR) and UV-visible spectroscopy.
  • Employed constant DNA concentration (6.25 mM) with varying alkaloid/polynucleotide ratios.
  • Analyzed interactions in aqueous solution at physiological conditions.

Main Results:

  • Spectroscopic evidence confirmed significant binding of all tested alkaloids to DNA.
  • Determined binding constants: K(harmine)-DNA=3.44x10^7 M⁻¹, K(harmalol)-DNA=6.43x10^5 M⁻¹, K(harmaline)-DNA=3.82x10^5 M⁻¹, K(harmane)-DNA=1.63x10^5 M⁻¹, K(tryptoline)-DNA=1.11x10^5 M⁻¹.
  • Established binding affinity order: harmine > harmalol > harmaline > harmane > tryptoline.

Conclusions:

  • The study demonstrates varying affinities of beta-carboline alkaloids for DNA, with harmine being the most potent binder.
  • Alkaloid-DNA interactions did not induce changes in DNA secondary structure, preserving the B-family conformation.
  • These findings contribute to understanding the molecular basis of beta-carboline's potential antitumor effects.