Origin and mechanism of terpene biosynthesis in Pseudopterogorgia spp

The goal of this work was to investigate the biosynthetic origins of diterpene natural products (pseudopterosins, kallolides, bipinnatins, and cembrenes) from corals of the genus Pseudopterogorgia as well as the biosynthetic pathways by which they are produced. These studies have shown that the pseudopterosins from Pseudopterogorgia elisabethae are biosynthesized within the algal symbiont (or possibly a bacterium or fungus associated with the symbiont), are not inducible by manipulation of light levels, and do not change as a result of transplantation to new locations. Studies on Pseudopterogorgia bipinnata revealed that only one chemotype is capable of biosynthesizing the kallolide family of diterpenes. The biosynthetic pathway which gives rise to the kallolides has been shown to involve members of another family of diterpenes, the bipinnatins, which coexist within the coral holobiont. Two diterpene cyclase products have been discovered within P. bipinnata chemotype A, cembrene and neocembrene, and it has been shown that neocembrene gives rise to the kallolides. Finally, the enzymatic conversion of bipinnatin J to kallolide A has shown for the first time that these compounds are in fact biogenetically related.