Antifouling Diterpenoids from the Sponge Dendrilla antarctica

Abstract

Two nor‐diterpenes, 9,11‐dihydrogracilin A (1) and the previously unreported 9,11‐dihydrogracillinone A (2), were isolated from the sponge Dendrilla antarctica. The sponge was collected by trawling at a depth of 49 m, from the research vessel Puerto Deseado, near the coast of Tierra del Fuego, farther north than the reported habitat for this species. Since these compounds were particularly abundant and the sponge was free from epibionts, both 1 and 2 were included in soluble‐matrix paints and tested for antifouling activity in the ocean. The results obtained from these experiments clearly indicated a potent antifouling activity for both compounds against a variety of colonizing organisms, and established a probable role as natural antifoulants for these abundant secondary metabolites and other structurally related compounds previously isolated from Dendrilla spp.

Marine natural products

“…A new dolabellane 1072 came from a Luffariella sponge, 415 while a dredged Antarctic Dendrilla sponge yielded spongian diterpenoid 1073 that was inactive in antifouling assays. 454 A further rearranged spongian diterpenoid 1074 was obtained from a Saudi Arabian Spongia along with several oxidised and linear sesterterpenoids 1075–1077 , respectively. 455 Other linear sesterterpenoids were obtained from further Luffariella sponges collected in China 1078–1090 , and Japan 1091 and 1092 ; the latter study made use of chemical reduction using AD-mix to aid in structure elucidation.…”

Anti‐Barnacle Activities of Isothiocyanates Derived from β‐Citronellol and Their Structure–Activity Relationships

“…Natural products with AF activities are a source of promising alternatives to synthetic ones [13−17] . In particular, terpenes and their derivatives isolated from marine organisms, such as nudibranchs, algae, and sponges, have attracted attention because of their AF activities [18–22] . Recent structure–activity relationship studies focused on the AF activity of 3‐isocyanotheonellin, which is a sesquiterpene isolated from nudibranchs [23] .…”

A Chemo-Ecological Investigation of Dendrilla antarctica Topsent, 1905: Identification of Deceptionin and the Effects of Heat Stress and Predation Pressure on Its Terpene Profiles

“…Its chemical defences, mostly diterpenoids, provide the sponge with protection to avoid predation [ 12 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Potential predators for the species include sympatric generalist predators like the sea star O. validus , omnivorous amphipods, or the common nudibranch Doris kerguelenensis [ 26 , 27 ].…”

“…The role of chemical ecology is pivotal in these communities [ 28 ] and its relevance for sponges has become clear over recent years [ 18 , 22 , 29 , 30 ]. For D. antarctica , the defensive role of its metabolites represents an ecological advantage that may be affected by global change, since increasing water temperatures may affect, for example, the production of these chemicals and thus the sponge’s protection against potential predators.…”