Hyrtios erectus

From the Okinawan sponge Hyrtios erectus was isolated hyrtiosal (154), possessing a novel rearranged tricarbocyclic skeleton (hyrtiosane) [164], Its structure was confirmed by total synthesis [165], This compound exhibited in vitro antiproliferative activity against KB cells with an IC50 of 3.0 pg/ml [164],... 

Squalenoid triterpenes are particularly rare in dictyocer-atid sponges, the first and maybe the only known example being a 7,18-diketosqualenoid isolated from an Indonesian Hyrtios erectus. The absolute configtiration was shown to be R,R by synthesis (Williams, Tahir, and Andersen, 1999 Enders and SchiiReler, 2002). 

The species Hyrtios erecta and Hyrtios erectus are considered identical. 

Enders, D. and Schufieler, T. (2002) First highly effident asymmetric synthesis of the Hyrtios erectus drketotriterpenoid. Synthesis, 2280-2288. 

Williams, D.E., Tahii A., and Andersen, R.J. (1999) A new acyclic diketotriterpenoid isolated from the Indonesian marine sponge Hyrtios erectus. J. Nat. Prod., 62, 653-654. 

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