Cytotoxic and NF-κB inhibitory sesquiterpene lactones from Piptocoma rufescens.
Six new (1-6) and eight known germacranolide-type sesquiterpene lactones, along with several known phenylpropanol coumarates and methylated flavonoids, were isolated from the leaves of Piptocoma rufescens, collected in the Dominican Republic. The new compounds were identified by analysis of their spectroscopic data, with the molecular structure of 3 being established by single-crystal X-ray diffraction. The absolute configurations of the sesquiterpene lactones isolated were determined from their CD and NOESY NMR spectra, together with the analysis of Mosher ester reactions. Bioassay screening results showed the majority of the sesquiterpene lactones isolated (1-13) to be highly cytotoxic toward the HT-29 human colon cancer cell line, with the most potent compound being 15-deoxygoyazensolide (10, IC(50), 0.26 µM). In addition, several of the sesquiterpene lactones exhibited NF-κB (p65) inhibitory activity.
Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA.
Yulin
Y
Ren
Ulyana Muñoz
UM
Acuña
Francisco
F
Jiménez
Ricardo
R
García
Melciades
M
Mejía
Heebyung
H
Chai
Judith C
JC
Gallucci
Norman R
NR
Farnsworth
Djaja D
DD
Soejarto
Esperanza J
EJ
Carcache de Blanco
A Douglas
AD
Kinghorn