Echinoclathria

The sponge Agelas dispar from the Bahamas contained pyridinebetaine B (494) [420]. Echinoclathrines B-C (495-496) are members of a new class of pyridine alkaloids from an Okinawan species of Echinoclathria. They exhibit weak immunosuppressive activity [421]. 

Echinoclasterol sulfate phenethylammonium salt (585), an antifungal and cytotoxic steroid, was isolated from the South Australian sponge Echinoclathria subhispida [472]. 

The thiol group can also be found in heterocyclic compounds such as 2-mercaptobenzothiazole (9) and echinoclathrine C (10). Compound 9 was isolated from the symbiont bacterium Micrococcus sp., which was obtained from the sponge Tedania ignis [13]. The pyridine alkaloid echinoclathrine C (10) and its S-acetylated derivative, echinoclathrine B (11), were isolated from the Okinawan sponge Echinoclathria sp. [14]. The position of the hydroxyl and acylamino group on the phenyl ring in echinoclathrines (11 and 10) was recently corrected [15]. Compound 11 showed weak immunosuppressive activity in the mixed lymphocyte reaction assay with an IC50 of 9.7 pg/ml [14]. 

Microcionidae° Antho, Artemisina, Clathria, Echinochalina, Echinoclathria, Holopsamma, Ophlitaspongia, Pandaros... 

Northcote, and Webb, 2002). Echinoclathria subhispida contains echinoclasterol sulfate, a polyhydroxylated sterol monosulfated at 2p, whose counterion is P-phenylethy-lammonium (see above) (Li et al, 1993). Clathsterol is a new 2p,3a- disulfated sterol which has anti-HIV-1 properties it was isolated from an undetermined species of the genus Clathria harvested in the Red Sea, in the Dahlak Archipelago (Rudi et al, 2001). This type of polyhydroxylated and sulfated sterol is common among halichondrid sponges (see above). 

Kitamura, A., Tanaka, J., Ohtani, I.I., and Higa, T. (1999) Echinoclathrins A-C a new class of pyridine alkaloids from an Okinawan sponge Echinoclathria sp. Tetrahedron, 55, 2487-2492. 

Li, H.-Y, Matstmaga, S., Fusetani, N Fujiki, H Murphy, P.T., Willis, R.H., and Baker, J.T. (1993) Echinoclasterol sulfate phenethylammonimn salt, a unique steroid sulfate from the marine sponge Echinoclathria subhispida. Tetrahedron Lett., 34, 5733-5736. 

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