New phloroglucinol derivatives from Hypericum papuanum.
Journal article

New phloroglucinol derivatives from Hypericum papuanum.

  • 2000-01-29
Published in:
  • Journal of natural products. - 2000
English Bioactivity-guided fractionation of the petroleum ether extract of the aerial parts of Hypericum papuanum led to the isolation of five new tricyclic phloroglucinol derivatives. On the basis of extensive 1D and 2D NMR experiments as well as MS studies, their structures were elucidated as the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-3-(1-methylvinyl)-5beta -H-tricyclo[ 5.3.1.0(1,5)]undec-8-ene-10,11-dione (1,2); the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylbutyryl)-3-(1-methylvinyl)-5beta-H-++ +tricyclo[5. 3.1.0(1,5)]undec-8-ene-10,11-dione (3, 4), and 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-5beta-H-tricyclo[5.3 .1.0(1, 5)]undec-8-ene-10,11-dione (5), and their corresponding tautomers (1a, 2a, 3a, 4a, 5a). Compounds 1/1a-5/5a were named ialibinones A-E, respectively. Compounds 1/1a-4/4a showed antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Micrococcus luteus.
Language
  • English
Open access status
closed
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Persistent URL
https://sonar.ch/global/documents/284532
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