Aplidium genus

The culture of Aspergillus niger, collected from an orange tunicate of the genus Aplidium on an island of Fiji, led to a series of dght merosesquiterpenes, yanuthones A-E, and other derivatives related to them (Bugni et al, 2000). Yanuthones are the only meroterpenes that have been isolated from marine fiingi. 

Curiously, the conformation of ds-decalin in lepadin A is the same as that of pumiliotoxin C, extracted from toads of the family Dendrobatidae, especially Den-drobates pumilio (Daly et al, 1969). Subsequently, lepadins B-H were isolated from the same species, Clavelina lepadiformis, harvested in Norway and from its predator, the platyhelminth Prostheceraeus villatus, from the species Aplidium tabascum and an undetermined species of the genus Didemnum, both collected in Australia on the Great Barrier Reef The ds-decalin nuclei of lepadins exist with two different conformations depending on whether the NH bond is located in an axial or equatorial position... 

More than 200 molecules have been characterized in polydinid asddians, but half of them come from the single genus Aplidium and nearly 80 structures were isolated from the two genera Ritterella and Pseudodistoma. The other four genera studied for their secondary metabolites, Aplidiopsis, Pharyngodictyon, Polyclinum and Synoicum, have yielded only about 20 derivatives and these appear to be present in relatively small amounts. 

Aplidiasphingosine is an atypical sphingosine insofar as the amino alcohol part is set on a diterpenic chain whose origin may be phytol. Isolated in 1978 from an undetermined species of the genus Aplidium harvested in the Caribbean, this antimicrobial and moderately cytotoxic derivative has the configuration 2(1 ),3(J ),13(S), 14(1 ). 

The most original nitrogenous derivatives of the family Polyclinidae, and perhaps of the phylum Tunicata, may be aplidites A-G, isolated from an Australian spedes of the genus Aplidium. These alkaloids are the first examples of natural orthonitrites and their structure includes one metacydophane and two macrolactones. None seems to have any particular biological properties (Murray et al, 1995). 

Zollo, F., Finamore, E., Gargiulo, D., Riedo, R., and Mrnale, L. (1986) Marine sterols. Coprostanols and 4a-methyl sterols from Mediterranean tunicates. Comp. Biochem. Physiol., 85B, 559—560. Zubia, E., Ortega, M.J., and Javier, S. (2005) Natural chemistry in marine asddians of the genus Aplidium. Mini-Rev. Org. Chem., 2, 389—399. 

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