Sponges Spongistatin

Just as iodine is used to treat cuts and chlorine (bleach) to disinfect bathrooms, our white blood cells generate chlorine and bromine to kill germs and fight infection. The sponge metabolite spongistatin and the blue-green... 

A series of extremely potent antitumor macrolides, known as the spongistatins, have been reported from four different sponges, Spongia sp. (52),... 

In the universe of biologically active natural products, the spirocyclic moiety is a unique and key structural motif. For example, there are over 300 spiroketal natural products including the aver-mectins and milbemycins, which demonstrate a range of antiparasitic activity with low toxicity (Figure 7.4). ° A semisynthetic derivative, ivermectin, is used in animals to treat parasite infestations. The spongistatins exhibit anticancer activity by disrupting mbulin polymerization. Okadaic acid is a cytotoxin found in marine sponges. 

Spongistatins 113, also referred to as altohyrtins in the literature, are complex marine macrolides that were isolated from marine sponges (Figure 19.10) [60]. Aside from the formidable structure, interest in these compounds has been stimulated due to their potent antitumor activity. Schwenter and Vogel, who have developed a new methodology for the preparation of polypropionates based on a double [4+3] cycloaddition, saw the spongistatins as an opportunity to... 

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