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Planta Med 1998; 64(6): 511-515
DOI: 10.1055/s-2006-957504
Papers
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

Prenylflavonoids: A New Class of Non-Steroidal Phytoestrogen (Part 1). Isolation of 8-Isopentenylnaringenin and an Initial Study on its Structure-Activity Relationship

Masahiro Kitaoka1 , Hiroshi Kadokawa1 , Machiko Sugano1 , Kazuo Ichikawa1 , Motohiko Taki2 , Sachiko Takaishi2 , Yasuteru lijima2 , Shinya Tsutsumi3 , Malee Boriboon4 , Toshiyuki Akiyama1
  • 1Exploratory Chemistry Research Laboratories, Sankyo Co., Ltd., Shinagawa-ku, Tokyo, Japan
  • 2Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., Shinagawa-ku, Tokyo, Japan
  • 3Analytical and Metabolic Research Laboratories, Sankyo Co., Ltd., Shinagawa-ku, Tokyo, Japan
  • 4Thai-Sankyo Co., Ltd., Dindaeng District, Bangkok, Thailand
Further Information

Publication History

1997

1998

Publication Date:
01 February 2007 (online)

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Abstract

Bioassay-guided fractionation of a methanolic extract of a Thai crude drug, derived from heartwood of Anaxagorea luzonensis A. Gray (Annonaceae), resulted in the isolation of 8-isopentenylnaringenin (1) as an estrogen agonist with an activity of about an order of magnitude greater than genistein. Various flavonoids possessing isopentenyl side chains in the A-ring have been prepared and evaluated for their ability to bind estrogen receptor. In addition, enantiomers of 1 were separated and the respective enantiomers were assayed. These studies have demonstrated that the presence of an 8-isopentenyl group is an important factor for binding. Flavones, flavanones and flavonols having an isopentenyl substituent at C-8 exhibited an appreciable affinity for estrogen receptor. Conversely, isoflavones possessing an 8-isopentenyl substituent at C-8 did not show this activity. Movement of the isopentenyl group from position 8 to 6 resulted in loss of the activity. No significant difference was observed between 2(S)- and 2(R)-enantiomers of 1 in their binding affinity. Prenylflavonoids are reported to possess a wide range of biological activities; however, estrogenic activity has not been described.

Key words

Anaxagorea luzonensis A. Gray - Annonaceae - prenylflavonoid - non-steroidal estrogen agonist - phytoestrogen - isopentenylnaringenin - isopentenylapigenin

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