To investigate the bioactive constituents for evaluation of cytotoxicity, six new diterpenoids¡]1-6¡^and one known compound¡]7¡^were isolated from a sample of soft coral Cespitularia sp. collected in Taiwan.These diterpenoids were divided into three skeletons: GXX-7-L3-1-2¡]1¡^, G8-5-L2-8-1¡]3¡^and G8-4-L3-9-1¡]4¡^are verticillane skeleton. GXX-7-L3-4-1¡]2¡^possesses a cespitularane skeleton. G8-4-L3-7-1¡]5¡^, G8-4-L3-8-1¡]6¡^and cespitularin E ¡]7¡^ contain a norverticillane skeleton.Compound 1 contains an £\,£]-unsaturated ketone at C-11, C-12 and C-10, an ethyl ester group at C-20 position, and a hydroxyl group at C-6 position. There is a £\-hydroxy-£],£^-epoxy-£_-hydroxy furan in compound 3. Compound 4 contains a methyl group at C-20 position, an epoxy ring at C-7 and C-8 position, and loses a hydroxyl group at C-6. Compound 2 has two acetoxyl groups at C-6 and C-20 position. Compound 5 contains an £\,£]-unsaturated ketone at C-11, C-12 and C-10, and olefinic double bond at C-7 and C-8 conjugated with ketone group at C-6 .The olefinic double bond at C-7 and C-8 is oxygenized to an epoxy ring and the ketone at C-6 is reduced to a hydroxyl group in compound 6.The ketone in compound 5 is reduced to a hydroxyl group in compound 7. All of these structures were elucidated on basis of extensive spectroscopic analysis and chemical derivatization.The configuration of hydroxyl group at C-6 in 1 was determined to be £] orientation by using Mosher¡¦s method. All of the isolated diterpenoids were tested against a panel of human tumor cell lines.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0726106-104051 |
| Date | 26 July 2006 |
| Creators | Wu, Ying-Ru |
| Contributors | none, none, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726106-104051 |
| Rights | withheld, Copyright information available at source archive |
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