Eleutherobin
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| Erythropodium caribaeorum |
Erythropodium caribaeorum (polyps open) |
Eleutherobin is a diterpene glycoside that has been shown to be a potent cancer cell inhibitor with an IC50 similar to that of paclitaxel (Taxol®). Assays in the National Cancer Institute’s 60 cell line panel showed a 100-fold greater potency over the mean cytotoxicity towards breast, renal, ovarian and lung cancer cell lines. It has also been demonstrated that eleutherobin is active in paclitaxel-resistant cancer cell lines. Significantly, eleutherobin was found to stabilize microtubules by competing for the paclitaxel binding site. The initial discovery of eleutherobin was from an examination of the soft coral Eleutherobia sp. however, development of this drug was severely hampered as no further samples of the coral could be obtained. Eleutherobin and a series of related compounds were subsequently isolated from the Caribbean gorgonian coral Erythropodium caribaeorum.
The sarcodictyins are diterpenes that are closely related to eleutherobin and have been isolated from a number of corals including: Eleutherobia aurea from South Africa , Bellonella albiflora from Japan , Sarcodictyon roseum from the Mediterranean, as well as E. caribaeorum from the Caribbean . The sarcodictyins have been shown to exhibit significant cytotoxicity to various cancer cell lines yet not at the levels of eleutherobin.
A current project in our research group is focused on elucidating the biosynthetic origin of the eleutherobin family of diterpenes. Within our microbiology program, we are also using a variety of culture dependent and culture independent methods to assess the microbial diversity in Erythropodium caribaeorum.
