Antiproliferative compounds of Helmiopsis sphaerocarpa from the Madagascar rainforest.
Bioassay-directed separation of an ethanol extract of the leaves of Helmiopsis sphaerocarpa L.C. Barnett (Sterculiaceae) led to the isolation of the new compound 14alpha,15alpha-epoxy-3beta-hydroxytaraxerane (1) and the four known compounds taraxerol (2), stigmast-5-en-3-ol (3), 5alpha,8alpha-epidioxy-24(S)-methylcholesta-6,22-dien-3beta-ol (4), and 24xi-hydroperoxy-24-ethylcholesta-4,28(29)-dien-3-one (5). The structure of the new compound 1 was established on the basis of interpretation of its 1D and 2D NMR spectroscopic data. All the compounds were tested against A2780 human ovarian cancer cell lines, and compounds 4 and 5 showed mild antiproliferative activity, with IC(50) values of 16 and 7 microg mL(-1), respectively.
Cao
Shugeng
S
Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA. shugeng_cao@hms.harvard.edu
Brodie
Peggy
P
Miller
James S
JS
Birkinshaw
Chris
C
Rakotondrafara
A
A
Andriantsiferana
Rabodo
R
Rasamison
Vincent E
VE
Kingston
David G I
DG
D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D000431:Ethanol; D005260:Female; D006801:Humans; D008270:Madagascar; D009682:Magnetic Resonance Spectroscopy; D019660:Malvaceae / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000302:isolation & purification* / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*
D010936:Plant Extracts; D000431:Ethanol