A new diterpene from the sponge Aplysilla Rosea

✍ Scribed by R. Kazlauskas; P.T. Murphy; R.J. Wells; J.J. Daly

• Publisher: Elsevier Science
• Year: 1979
• Tongue: French
• Weight: 196 KB
• Volume: 20
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)93584-1

✦ Synopsis

Sponges of the orders

Dictyoceratida and Dendroceratida, the spiculeless horny sponges, have produced a plethora of terpenoid metabolites' including a new diterpenoid ring system of which isoagathalactone (11, from certain collections of the Dictyoceratid sponge Spongia officinalis, was the first example*. We have reported3 the isolation of the four closely related diterpene alcohols (21-(51 and their acetates, which incorporated the same diterpene carbocyclic ring system as (11, from various collections of several related species of the genus Spongia, collected on the Australian Great Barrier Reef. We now describe the isolation of a novel diterpene triacetate, aplysillin (61 from the Dendroceratid sponge Aplysilla rosea collected in New Zealand. Aplysilla rosea is a small red-purple coloured sponge which occurs as isolated individuals in localised areas and is difficult to collect in reasonable quantity. Extraction of a small homogenised sample of A. rosea (509 wet weight) with methanol/diethyl ether (1:l) followed by -partition of the total extract between diethyl ether and water gave an ether layer from which 34mg of the new diterpene (61*, m.p. 169A171' [al:" + 13" (c = 0.5, CHC131, was isolated by preparative layer chromatography on silica gel. The CI (NH31 mass spectrum of (61 showed a strong M+ + 18 at 482 a.m.u. and the formula C26H4007 was established by analysis. Major fragment ions at 345 and 285 a.m.u. in the CI mass spectrum suggested the loss of two and three molecules of acetic acid respectively. The 70 e.v. EI mass spectrum of (61 showed no molecular ion, the first fragment ion appearing at 284 a.m.u. (C20H280, M* z 3 AcOHl. * We have suggested3'" the name 'spongan' for the hypothetical diterpene ether (101. Thus (61 can be named 12a,15a,& triacetoxyspongan.