3.3. Compounds Toxic to Fertilized Sea Urchin Eggs
Tenuecyclamides A–D (Figure 4) and known antibiotic Borophycin were extracted from Nostoc
spongiaeforme var. tenue (TAU strain IL-184-6) isolated from a litophytic sample collected in the
Volcani Center, Bet Dagan, Israel [18]. Banker and Carmeli (1998) demonstrated that Tenuecyclamide
A, C and D inhibit the division of sea urchin embryos with an effective dose (ED100) value of 10.8 μM,