As part of a project directed toward the discovery of new
cancer chemopreventive agents from plants, two new natural products,
asparagusic acid anti-S-
oxide methyl
ester (1) and
asparagusic acid syn-S-
oxide methyl
ester (2), a new acetylenic compound, 2-hydroxyasparenyn [3',4'-trans-2-hydroxy-1-methoxy-4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]-
benzene] (3), as well as eleven known compounds, asparenyn (4), asparenyol (5), (+/-)-1-monopalmitin (6),
ferulic acid (7), 1,3-O-di-p-coumaroylglycerol (8), 1-O-feruloyl-3-O-p-coumaroylglycerol (9), blumenol C, (+/-)-epipinoresinol,
linoleic acid, 1,3-O-diferuloylglycerol, and 1,2-O-diferuloylglycerol, were isolated from an
ethyl acetate-soluble fraction of the
methanol extract of the aerial parts of Asparagus officinalis (Asparagus), using a bioassay based on the inhibition of
cyclooxygenase-2 to monitor chromatographic fractionation. The structures of compounds 1-3 were elucidated by 1D- and 2D-NMR experiments ((1)H NMR, (13)C NMR, DEPT, COSY,
HMQC, HMBC and NOESY). All the isolates were evaluated for their inhibitory effects against both
cyclooxygenase-1 and -2, with the most active compound being
linoleic acid.