Molecular formula: C₃₁H₄₈O₃N₄

Relative molecular mass: 524

Character: light yellow powder

Origin: Papua New Guinea sponge Auletta cf.constricta

Biological activity and toxicity: inhibiting all kinds of tumour cells. The

Result of the extra-organismal experiment: A549 (IC₅₀=4.1µmo/L),

HT-29 (IC₅₀=2.8µmo/L), B16/F10 (IC₅₀=3.3µmo/L), P-388 (IC₅₀=0.74µmo/L).