Inhibition of angiotensin-I-converting enzyme by tetrahydroxyxanthones isolated from Tripterospermum lanceolatum

J Nat Prod. 1992 May;55(5):691-5. doi: 10.1021/np50083a025.


Five tetrahydroxyxanthones, 3,4,6,7-tetrahydroxyxanthone [1], 1,3,5,6-tetrahydroxyxanthone [2], 3,4,5,6-tetrahydroxyxanthone [3], 1,3,6,7-tetrahydroxyxanthone [4], and 2,3,6,7-tetrahydroxyxanthone [5] isolated from Tripterospermum lanceolatum inhibited angiotensin-I-converting-enzyme activity in a dose-dependent manner. The mode of inhibition of the tetrahydroxyxanthones (THXs) was found to be competitive inhibition. When the tetrahydroxy groups of THXs were blocked with acetyl groups, the angiotensin-I-converting-enzyme inhibitory activity was abolished, suggesting that the tetrahydroxy groups are indispensible for the inhibitory activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin-Converting Enzyme Inhibitors / isolation & purification
  • Angiotensin-Converting Enzyme Inhibitors / pharmacology*
  • Animals
  • Drugs, Chinese Herbal / chemistry*
  • Male
  • Rats
  • Rats, Inbred SHR
  • Xanthenes / isolation & purification
  • Xanthenes / pharmacology*


  • Angiotensin-Converting Enzyme Inhibitors
  • Drugs, Chinese Herbal
  • Xanthenes