title: Isolation and Characterization of Aromatase Inhibitors from Brassaiopsis glomerulata (Araliaceae).
abstract: 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.
authors.affiliation: 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.
authors.forename: Marcy J
authors.initials: MJ
authors.lastname: Balunas
authors.forename: Bin
authors.initials: B
authors.lastname: Su
authors.forename: Soedarsono
authors.initials: S
authors.lastname: Riswan
authors.forename: Harry H S
authors.initials: HH
authors.lastname: Fong
authors.forename: Robert W
authors.initials: RW
authors.lastname: Brueggemeier
authors.forename: John M
authors.initials: JM
authors.lastname: Pezzuto
authors.forename: A Douglas
authors.initials: AD
authors.lastname: Kinghorn