Lissoclinum patella Patellamides

Schmidt, E.W., Nelson, J.T., Rasko, D.A. et al. (2005) Patellamide A and C biosynthesis by a microcin-like pathway in Prochloron didemni, the cyanobacterial symbiont of Lissoclinum patella. Proceedings of the National Academy of Sciences of the United States of America, 102, 7315. 

Schmidt EW, Nelson JT, Rasko DA, Sudek S, Eisen JA, Haygood MG, Ravel J (2005) Patellamide A and C Biosynthesis by a Microcin-like Pathway in Prochloron didemni, the Cyanobacterial Symbiont of Lissoclinum patella. Proc Natl Acad Sci USA 102 7315... 

Ascidians are marine filter feeders with a rich natural products chemistry that five commonly associated with symbiotic bacteria (88, 89, 109). A well-studied symbiosis consists of photosynthetic Prochloron spp. cyanobacteria that occur in ascidians of the family Didemnidae (110). Prochloron spp. also can be found in bacterial mat structures of stromatoliths (111) but so far have not been detected outside of such structured environments. From didemnid ascidians, numerous cytotoxic cyclic peptides of the patellamide group (Fig. 5) were isolated (109, 112, 113). Mechanical separation of the Prochloron sp. symbiont from its host Lissoclinum patella and subsequent genome sequencing revealed a set of biosynthetic genes that after transfer into E. coli enabled this bacterium to produce two different patellamides (114). The genes also were identified in an independent study by screening a library of Prochloron sp. DNA... 

The cyclamides are small cyclic peptides that characteristically contain multiple thiazole, thiazoline, oxazole, and oxazoline rings, which are derived from cysteine, serine, and threonine residues. Some of the first examples of this class to be described were the patellamides (53-55) from the tunicate Lissoclinum patella, although it was later determined they were produced by the symbiotic cyanobacterium Prochloron sp. The structures were solved by a combination of acid hydrolysis and GC analysis, coupled with 2D NMR. Smaller cyclic peptides from this class include the hexapeptides westiellamide (56) and microcyclamide (57) from M. aeruginosa Many members of the class possess cytotoxic properties, although their biological function or mechanism of action is not fully understood. In contrast to many cyanobacterial peptides, aside from the unusual heterocyclic residues, these peptides generally contain only ribosomal amino acids. 

A review describes the pharmacological properties of l,2-benzisothiazoles. In connection with thiazoles, we find several reviews or papers thiazoles in food aromas patellamides, which are antineoplastic cyclic peptides, from the marine tunicate Lissoclinum patella, which contain an unusual fused oxazoline-thiazole unit and polythiazole-containing peptide antibiotics. An interesting total synthesis of the aglycon of bleomycin A2 should also be mentioned. ... 

Lissoclinum bistratum contains mostly cyclic hexapepti-des/ but Lissoclinum patella has yielded patellamides A-G (Figure 28.15), which are regarded as octapeptides, as well as ulithiacyclamides A and B and pre-ulithiacydamide these last three peptides are characterized by the presence of an intracyclic disulfide bridge. Lissoclinum patella has also yielded asddiacydamide, which had been isolated in 1983 from an tmdetermined ascidian, and tawicyclamides A and which appear to be currently the only cyclic peptides containing only thiazoles or thiazolines. These... 

In, Y, Doi, M., Inoue, M., Ishida, T., Hamada, Y, and Shioiri, T. (1994a) Patellamide A, a cytotoxic cyclic peptide from the ascidian Lissoclinum patella. Acta Crystcdlgr. Sect. C, 50, 432-434. 

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