In order to search for novel bioactive compounds, we have investigated the
secondary metabolites of the soft corals Nephthea erecta, Lobophytum durum,
and Sarcophyton ehrenbergi. Chemical examinations on the organic extracts
of N. erecta, have resulted in the isolation of six new sesquiterpenoids (1-6),
a new calamenene-type sesquiterpene with a mercaptan group, erectathiol (7),
a new tri-nor-eudesmadienone (8), two known sesquiterpenoids (9 and 10),
one novel seco-germacrane sesquiterpene (11), three unexpected artificial
19-oxygenated steroids (12-14), as well as twelve new polyhydroxylated
steroids (15-26). Furthermore, twelve new cembranolids, durumolides A-L
(27-38), three unprecedented hemiketal cembranoids, durumhemiketalolides
A-C (39-41), six previously described cembranolids (42-47), together with
one known metabolite, peridinin (48), were isolated from the acetone extracts
of L. durum. Chemical investigation of S. ehrenbergi, has led to the isolation
of a known ceramide (49), two new cerebrosides, sarcoehrenosides A (50) and
B (51), along with three previously characterized cerebrosides (52-54). The
structures of the isolated metabolites were elucidated through extensive
spectroscopic analyses, while the relative stereochemistry of 10 and 44 were
further confirmed by X-ray diffraction analyses. Moreover, the absolute
configurations of 24, 25, 29, 34, 38, and 43-45 were established by
application of modified Mosher¡¦s method. The cytotoxicities, antibacterial
activities, anti-inflammatory effects, and inhibition assay of HCMV (human
cytomegalovirus) endonuclease activities of these isolated metabolites were
evaluated in vitro.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0302109-114410 |
| Date | 02 March 2009 |
| Creators | Cheng, Shi-Yie |
| Contributors | Ian-Lih Tsai, Ling-Ching Chen, Jyh-Horng Sheu, Ping-Jyun Sung, Chun-Nan Lin, Chang-Yih Duh |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0302109-114410 |
| Rights | not_available, Copyright information available at source archive |
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