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  Theme-based Research Scheme–Call for Proposal Chinese children

  Theme-based Research Scheme–Call for Preliminary Proposals

  Launch of New Joint Research Schemes

  Nanotherapeutics in Angiogenesis: Synthesis and in Vivo Assessment of Drug Efficacy and Biocompatibility in the Zebrafish Embryos

  Nimodipine suppresses chemokine release via inhibition of adenosine uptake in endothelial cells

  DNA-binding Activities of Some Alkaloids from Chinese Medicinal Herbs

  Development of a High Performance Liquid Chromatographic Method for the Quality Control of Rhizoma Smilacis Glabrae and its Derived Products

  Interactions between UGT isoenzymes and MRP transporters during the oral absorption process of Baicalein

  Gender Differences in the Regulation of Endothelium-Dependent Contracting Factor

  Areas of Excellence Scheme Project: Introducing the Work of the Hong Kong Institute of Economics and Business Strategy

  Areas of Excellence of Scheme Project: Building excellence in plant and agricultural biotechnology research

  RGC Collaborative Research Fund – Layman Summaries of Projects Funded in 2009/10 Exercise


In recent years, small organic molecules have attracted a great deal of interests of scientists in new drug design targeting biological macro-molecules, such as proteins, enzymes, receptors and nucleic acids (DNA and RNA). The interactions of drug with DNA comprise noncovalent binding and covalent bonding. The former one is reversible but the later one is irreversible. Most of the interactions between drugs and DNA belong to reversible binding, except for aristolochic acids in some toxic herbs from Aristolochiaceae which damage DNA irreversibly.

Prof. Jiang’s studies revealed that some
anti-cancer alkaloids, such as berberine and its synthesized dimer, chelerythrine, sanguinarine and nitidine can specifically interact with DNA through an intercalating mode. In order to clarify their molecular mechanism of anti-cancer activities, Prof. Jiang employed a combination of spectrometric and biomedical techniques, including mass spectrometry, fluorometric analysis, spectrophotomeric titration, ethidium displacement, DNA polymerase stop assay etc., to intensively investigate the noncovalent irreversible binding of these alkaloids to several types of DNA, such as double-stranded, bulged and G-quadruplex DNA. The studies covered, for example, measurement of binding constants to designed DNA with different sequences and discussion of structure-activity relationship of these alkaloids. In addition, a series of dimeric berberines were synthesized, which were found to be much stronger DNA-binding
"Our data provided concrete evidence for the most reasonable arrangement of "Beads-on-a-String" structure of human telomeric DNA. Furthermore, a novel model for the binding of sanguinarine to "Beads-on-a-String" human telomeric DNA was established for the first time. This novel binding model supplied important guidance for structure-based anti-cancer drug design targeting human telomeric DNA, "Professor Jiang addressed particularly the results from the studies on the interaction between sanguinarine and G-quadruplex DNA which exists in telomere of human chromosome. "The alkaloid berberine is the main component of some common Chinese herbs, such as Rhizoma Coptidis ("Huang- Lian") and Cortex Phellodendri ("Huang-Bai"), whereas, sanguinarine and nitidine are being used as anti-microbial and anti-inflammatory agents in toothpaste and mouthwashes. The strong DNA-binding activities of berberine, sanguinarine and nitidine alert us to the safety concern of daily-used hygiene products containing these herbal alkaloids," Prof. Jiang commented from another angle on the significance of their DNA-binding research.

Prof Jiang, Zhi-Hong
School of Chinese Medicine
Hong Kong Baptist University