Anti-inflammatory agents

Pseudopterogorgia elisabethae is a known source of structurally interesting bioactive
metabolites. A detailed search for new, related compounds was undertaken in this study
which resulted in the isolation and characterization of more than ten new diterpenes with
serrulatane and ileabethane skeletons. Some of the new compounds isolated are closely
related terpenes with significant biological activity and others are likely to be key
biosynthetic intermediates. As a component of the development of a production method
of anti-inflammatory compounds such as seco-pseudopterosin and elisabethadione, a
synthesis of a seco-pseudoperosin aglycone from elisabethatriene was developed.

The octocoral Eunicea fusca is the source of important anti-inflammatory compounds
such as the diterpenes fuscol and the fuscosides. Evidence suggests that these
compounds are being produce by bacterial sources that live in symbiosis with the coral.
As part of an investigation to better understand the role of bacteria associated with E.
fusca , the characterization of the bacterial community using two different techniques
(culture dependent technique and culture independent technique) and sea water samples
was done. Sea water samples were used as a control to determine how closely associated
bacteria are to this octocoral. The polymerase chain reaction (PCR) with universal
bacterial primers FC27 and RC 1492 specific to prokaryotic 16S rDNA gene sequences
was used to characterize the total bacterial population when using both the culturable and
the non-culturable approaches. The results indicate a diverse group of bacteria associated to E. fusca composed of 10 different groups. The pro teo bacteria group was the most
predominant group when both techniques were used. The a-proteobacteria represented
the highest percentage of bacteria associated to E. fusca.

Pseudopterosin C is a novel diterpene glycoside isolated from the Caribbean gorgonian coral, Pseudopterogorgia elisabethae. Pseudopterosin C is non-steroidal and has been shown to exhibit promising anti-inflammatory and analgesic properties. The in vitro production of pseudopterosin C through biosynthetic methods has been examined. A cell-free system as well as an enzyme precipitate capable of transforming terpene precursors to the product has been developed. The parameters toward optimizing the enzymatic production through cofactor requirements, differing terpene precursors and sugars were investigated.

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.