Five new tetranortriterpenoids, methyl 3 tigloyloxy-2,6-dihydroxy-1-ox
o-meliac-8(30)-enate, methyl 3 eta-tigloyloxy-2-hydroxy-1-oxo-meliac-8
(30)-enate, methyl 3 beta-tiglogloxy-2-hydroxy-8 alpha,30 alpha-epoxy-
1-oxo-meliacate, methyl 3 beta-acetoxy-2,6-dihydroxy-8 alpha,30 alpha-
epoxy-1-oxo-meliacate and methyl 3 beta-isobutyryloxy-2,6-dihydroxy-8
alpha,30 alpha-epoxy-1-oxo-meliacate, were isolated from the seeds of
Swietenia macrophylla. The structure of these five tetranortriterpenoi
ds was established by comprehensive spectral analysis.