Studies on the Natural Products from the Taiwanese Soft Corals Clavularia viridis, Xenia florida, Cespitularia taeniata, Cespitularia hypotentaculata, and Sarcophyton stolidotum

by Cheng, Yuan-Bin

Abstract (Summary)
This dissertation mainly discussed the investigation of five different soft corals collected in Green Island and one soft coral collected in Kenting. They were identified as Clavularia viridis, Xenia florida, Cespitularia taeniata, Cespitularia hypotentaculata, and Sarcophyton stolidotum. In the isolation of these corals, there were sixty natural products discovered, including twenty night new compounds and three new derivatives. The research of soft coral Clavularia viridis has result in the isolation of six new prostanoids, designated as 4-deacetoxyl-12-O-deacetylclavulone I (1), 4-deacetoxyl-12-O-deacetylclavulone II (2), bromovulone II (3), iodovulone II (4), 4-deacetoxyl-12-O-deacetylclavuloneIII (5), and bromovulone III (6), together with seven known prostanoids, identified as clavulone I (33), clavulone II (34), chlorovulone II (35), 4-deacetoxylclavulone II (36), clavulone III (37), chlorovulone III (38), and 7-acetoxy-7,8-dihydroiodovulone I (39). In the investigation of the soft coral Xenia florida, three new compounds called florxenilides A-C (7-9), has been purified. The research also obtained seven xenicane-type diterpenes, xeniafaraunol A (40), xeniafaraunol B (41), florlide A (42), florlide C (43), florlide D (44), 9-deoxyxeniolide A (45), and 9-deoxyxeniolide B (46) in addition to two cadinene-type sesquiterpenes, xenitorins A (47) and B (48). Florxenilides A and C also treated with some chemical reagents to afford three new derivatives, 10-benzoylflorxenilide A (10), Florxenilide C monoacetate (11), and 10-dehydroflorxenilide A (12). Otherwise, the study in Cespitularia taeniata has afforded ten new nitrogen-containing compounds, cespitulactams D-K (13-20) and taenialactams A-B (21-22), in addition to four known compounds, atractylenolactam (49), cespitulactam A (50), cespitulactam B (51), and cespitularin F (52). Moreover, there were three new compounds, namely cespihypotins E, F, and H (23, 24, 25) have been discovered from another soft coral Cespitularia hypotentaculata. The study of this coral also observed seven known components called cespihypotin G (53), cespitulactone A (54), cespitularin F (52), cespitularin D (56), cespihypotins A-C (55, 57, 58). Investigation of the non-polar extract of the soft coral Sarcophyton stolidotum collected in Kenting resulted in the isolation of seven new 14-membered carbocyclic cembranes, sarcostolides A-G (26-32), together with two known cembranes isosarcophytoxide (59) and isosarcophine (60). All the structures of above metabolites were elucidated by physical and spectroscopic analyses including IR, Mass, UV, NMR, and optical rotation, and by compared with published data in many previous papers. The stereochemistry of these compounds as determined by NOESY experiments, CD spectroscopic data, and Mosher¡¦s methods. Cytotoxicity tests were measured by Dr. Kuo Yao-Haur and Dr. Guh Jih-Hwa. Isolated marine prostanoids showed potent activities against human prostate carcinoma (PC-3) and colon adenocarcinoma (HT-29) cells. Among them bromovulone III (6) had the most potent cytotoxicity against both cell lines at IC50 0.5
Bibliographical Information:

Advisor:C. N. Lin; Ya-Ching Shen; Hung-Non Chou; Meng-Hsien Chen; Jyh-Horng Sheu

School:National Sun Yat-Sen University

School Location:China - Taiwan

Source Type:Master's Thesis

Keywords:cytotoxicity diterpenoid marine natural product prostanoid


Date of Publication:07/16/2007

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