Symploca hydnoides

Several analogues of the dolastatins, potent cytotoxic compounds originally derived from the Indian Ocean seahare, Dolabella auricularia, have now been found in the marine cyanobacteria, Lyngbya majuscula and Symploca hydnoides. These discoveries support the proposal that the dolastatins isolated from D. auricularia are of dietary origin. The implications of such an observation to natural products programmes is discussed. Aspects of the structure elucidation of these complex molecules are also presented. 

Also isolated from Symploca hydnoides was symplostatin 2 (12), a cyclic depsipeptide with close structural analogy to dolastatin 13 (13) (Figure 4). It had in fact been suggested earlier that dolastatin 13 (13) most probably had a cyanobacterial dietary... 

Malevamide D 137, a highly cytotoxic peptide ester from a Hawaiian marine cyanobaeterium of Symploca hydnoides, showed IC50 values of 0.3-0.7 nM (0.2-0.5 ng/mL) against P-388 (mouse lymphoma), A-549 (human lung carcinoma), and HT-29 (human colon carcinoma) cell lines and 0.7 nM against the MEL-28(human melanoma) eell line. ... 

Malevamides A-E are other analogs of dolastatins that were isolated from the Hawaiian species Symploca laete-viridis and Symploca hydnoides. Malevamide D is strongly... 

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