Abstract
Three new norcembrane-based diterpenoids, leptocladolides A (
1
), B (
4
) and C (
5
), along with five known metabolites
6–
10
, have been isolated from the dichloromethane extract of a Taiwanese soft coral
Sinularia leptoclados. Furthermore, a chemical investigation on the dichloromethane extract of
S. parva has resulted in the isolation of two new related isomers, 1-
epi-leptocladolide A (
2
) and 7
E-leptocladolide A (
3
), in addition to
1
and
7
. The structures of new metabolites
1–
5
were elucidated on the basis of extensive spectroscopic analyses and their relative stereochemistries were determined by NOESY experiments. The new metabolites
1
and
3
have been shown to exhibit significant cytotoxic activity against KB and Hepa59T/VGH cancer cell lines.
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