Studies on the Natural Products from the Formosan Octocorals Briareum excavatum and Junceella fragilis

• Main Authors: Yu-Pei Chen, 陳玉珮
• Other Authors: Jhy-Horng Sheu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/49490911901787257117

碩士 === 國立中山大學 === 海洋資源學系研究所 === 93 === In connection with our long-standing interest in the chemical constituents of Formosan octocorals, we have investigated the octocorals Briarium excavatum and Junceella fragilis, collected at southern Taiwan coast. During the investigation, four new metabolites brianthiens D‐G (1‐4), have been isolated from Briareum excavatum. In addition, four 11,20-epoxybriaranes including three new metabolites, fragilides B‐D (5‐7), along with a known briarane (–)-11α,20α-epoxy-4-deacetoxyjunceellolide D (8), have been obtained from J. fragilis. The structure of 8 was revised as (–)-11β,20β-epoxy-4-deacetoxyjunceellolide D (8) by detailed spectral data analysis. The structures, including the relative configurations of the new briaranes 1‐7, were elucidated by spectroscopic methods. The structure of fragilide B (5) was further confirmed by X-ray diffraction analysis. The relationship between 13C NMR chemical shifts and conformation of the cyclohexane ring in briaranes possessing 11,20-epoxy group, are also described.