Formation and Conformation of Baicalin–Berberine and Wogonoside–Berberine Complexes Formation and Conformation of Baicalin–Berberine and Wogonoside–Berberine Complexes

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Author(s)

    • Wang Jing-Rong Wang Jing-Rong
    • State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology
    • Kouno Isao
    • Department of Natural Product Chemistry, Graduate School of Biomedical Sciences, Nagasaki University
    • Jiang Zhi-Hong
    • State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology

Abstract

It is well-known that baicalin–berberine complex (1) precipitates in the water decoction of numerous Chinese Medicinal formulae containing Radix Scutellariae and Rhizoma Coptidis or Cortex Phellodendri. In the current study, ionic interaction between the carboxylate ion of baicalin and the quaternary ammonium ion of berberine was revealed to be responsible for the formation of 1 and wogonoside–berberine (2) by using FAB-MS and NMR titration experiments. In addition, nuclear Overhauser effect spectroscopy (NOESY) correlations observed in 1 and 2 suggested quite different conformation of the two complexes, which was further supported by the fact that the [α]D of the canadine obtained by reduction of 1 is of an opposite sign to that obtained from 2. Partition coefficients (n-octanol/water) determination demonstrated 12–20 times larger partition coefficient of each complex (1, 2) than that of each single compound (baicalin, wogonoside, and berberine), indicating the significant role of the formation of the complex in the bioavailability enhancement of these pharmacologically active constituents.

It is well-known that baicalin–berberine complex (<b>1</b>) precipitates in the water decoction of numerous Chinese Medicinal formulae containing Radix Scutellariae and Rhizoma Coptidis or Cortex Phellodendri. In the current study, ionic interaction between the carboxylate ion of baicalin and the quaternary ammonium ion of berberine was revealed to be responsible for the formation of <b>1</b> and wogonoside–berberine (<b>2</b>) by using FAB-MS and NMR titration experiments. In addition, nuclear Overhauser effect spectroscopy (NOESY) correlations observed in <b>1</b> and <b>2</b> suggested quite different conformation of the two complexes, which was further supported by the fact that the [α]<sub>D</sub> of the canadine obtained by reduction of <b>1</b> is of an opposite sign to that obtained from <b>2</b>. Partition coefficients (<i>n</i>-octanol/water) determination demonstrated 12–20 times larger partition coefficient of each complex (<b>1</b>, <b>2</b>) than that of each single compound (baicalin, wogonoside, and berberine), indicating the significant role of the formation of the complex in the bioavailability enhancement of these pharmacologically active constituents.

Journal

  • Chemical and Pharmaceutical Bulletin

    Chemical and Pharmaceutical Bulletin 60(6), 706-711, 2012

    The Pharmaceutical Society of Japan

Codes

  • NII Article ID (NAID)
    130001852469
  • NII NACSIS-CAT ID (NCID)
    AA00602100
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    0009-2363
  • NDL Article ID
    023665862
  • NDL Call No.
    Z53-D167
  • Data Source
    NDL  IR  J-STAGE 
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