Structure Revision and Assignment of Absolute Stereochemistry of a Marine C₂₁ Bisfuranoterpene

Abstract

The C21 bisfuranoterpene (-)-isotetradehydrofurospongin-1 (6), previously isolated from a Western Australian Spongia sp., has been reisolated from a specimen of Spirastrella papilosa collected during scientific trawling operations in the Great Australian Bight. A 2D NMR analysis of 6 has prompted reassignment of the published structure 5, while degradation and chiral HPLC analysis have allowed determination of the absolute stereochemistry.

Heterocyclic Terpenes: Linear Furano‐ and Pyrroloterpenoids

“…143 A C 21 norsesterterpenoid originally reported to have two conjugated double bonds, 192, 129 has been revised to 193 on the basis of more complete spectroscopic data obtained from a sample isolated from an Australian specimen of Spirastrella papilosa. 144 The absolute stereochemistry was determined by degradation, and the name (−)-isotetrahydrofurospongin-1 proposed for this bisfuranoterpene. 148 A furanoterpene, designated dehydrofurodendin 202, was isolated from two different species of Madagascan sponges of the genus Lendenfeldia, both of which seem to be as yet undescribed.…”

Antimicrobial Activity of Untenospongin B, a Metabolite from the Marine Sponge Hippospongia communis collected from the Atlantic Coast of Morocco

“…These natural products may play a role in warding off predators, and perhaps they also repel fouling organisms. Marine sponges are also a well known source of a unique class of metabolites collectively known as C21 bisfuranoterpenes [ 7 , 8 , 9 ]. Early examples included (+)-furospongin-1 from Mediterranean Spongia officinalis as well as (−)-untenospongin A and B from an Okinawan Hippospongia sp.…”

The Role of Spongia sp. in the Discovery of Marine Lead Compounds

“…Subsequent work of Capon et al [ 59 ] on Spirastrella papilosa led to the reisolation of the compound, and revision of the proposed structure to 142 ( Figure 37 ), for which the name of (−)-isotetradehydrofurospongin-1 is proposed.…”