Isolation and Characterization of Aromatase Inhibitors from Brassaiopsis glomerulata (Araliaceae).
The hexane- and ethyl acetate-soluble extracts of the leaves of Brassaiopsis glomerulata (Blume) Regel (Araliaceae), collected in Indonesia, were found to inhibit aromatase, the rate-limiting enzyme in the production of estrogens from androgens, in both enzyme- and cell-based aromatase inhibition (AI) assays. Bioassay-guided fractionation led to the isolation of six known compounds of the steroid and triterpenoid classes (1-6) from the hexane extract, of which 6β-hydroxystimasta-4-en-3-one (5), was moderately active in the cell-based AI assay. Fractionation of the ethyl acetate extract afforded seven pure isolates (7-13) of the modified peptide, fatty acid, monoterpenoid, and benzenoid types, including six known compounds and the new natural product, N-benzoyl-L-phenylalanine methyl ester (9). The absolute stereochemistry of 9 and the other two peptides, 7 and 8, was determined by Marfey's analysis. Linoleic acid (10) was found to be active in the enzyme-based AI assay, while 9 and (-)-dehydrololiolide (12) showed activity in the cell-based AI assay.
Balunas
Marcy J
MJ
Program for Collaborative Research in the Pharmaceutical Sciences, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612.
Su
Bin
B
Riswan
Soedarsono
S
Fong
Harry H S
HH
Brueggemeier
Robert W
RW
Pezzuto
John M
JM
Kinghorn
A Douglas
AD