Cytotoxic cyclic peptides

Cytotoxic cyclic peptides have also been found in mollusks. Dolastatin peptides are a group of cyclic and linear peptides with prominent cell growth-suppressing activity that were isolated from the marine mollusk... 

Ascidiacyclamide (14), a cytotoxic, cyclic peptide, was isolated from an unidentified species of ascidian [40], The absolute configuration was determined and the structure confirmed by total synthesis [41]. An X-ray crystal structure was carried out [42] and further X-ray crystallographic studies determined the conformation of the molecule in the solid- and solution-states [43]. 

Total synthesis of marine cytotoxic cyclic peptides 91YZ1. 

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... 

Halobacillin was isolated by Trischman et al. in 1994 as a cytotoxic cyclic peptide from marine Bacillus sp °l Isohalobacillins, congeners of halobacillin, were also isolated as inhibitors of cholesteryl ester formation in macrophages, from a culture of Bacillus sp. A123 8, by Hasumi et al. in... 

The cytotoxic cyclic peptide, oriamide (34), containing the new 4-propenoyl-2-tyrosylthiazole unit, has been isolated from the blue marine sponge, Theonella sp., collected in Sodwana Bay [29]. This unusual aminoacid is reminiscent of the thiazole moiety early reported as a constituent of keramamide F (24) [22],... 

Dianthins, cytotoxic cyclic peptides isolated from the methanol extract of the traditional Chinese medical plant Dianthus superbus. Beside dianthin C, cyclo-(-Gly-Pro-Phe-Tyr-Val-Ile ), the dianthins D-F with similar... 

Patellamides B and C, Cytotoxic Cyclic Peptides from a Tunicate. 2. Their Real Structures have been Determined by Their Syntheses. Tetrahedron Lett. 26, 5159 (1985). 

Hawkins, C.J., Lavin, M.F., Marshall, K.A., Van den Brenk, A.L., and Watters, D.J. (1990) Structure-activity relationships of lissoclinamides cytotoxic cyclic peptides from the ascidian Lissoclinum patella. J. Med. Chem., 33, 1634-1638. 

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. 

Chill, L., Kashman, Y, and Schleyer, M. (1997) Oriamide, a new cytotoxic cyclic peptide containing a novel amino acid from the marine sponge Theondla sp. Tetrahedron, 53,16147-16152. 

Fusetani, N., Sugawara, T, Matsrmaga, S., and Hirota, H. (1991b) Orbicrdamide A, a novel cytotoxic cyclic peptide from a marine sponge Theonella sp. /. Am. Chem. Soc., 113, 7811-7812. 

Schmidt, E.W., Raventos-Suarez, C., Bifano, M., Menendez, A.T., Fairchild, C.R., and Faulkner, D.J. (2004) Sderitodermin A, a cytotoxic cyclic peptide from the lifhistid sponge Sderitoderma nodosum. J. Nat. Prod., 67, 475-478. 

Ibrahim. S.R.M., Edrada-Ebel, R.U., Mohamed, G.A., Youssef D.T.A., Wray. V., and Proksch, P. (2008b) Callyaerin G, a new cytotoxic cyclic peptide from the marine sponge Callyspor ia aerizutsa. ARKIVOC, 164-171. 

Boden, C. and Pattenden, G. (1994) Total synthesis of lissodinamide 5, a cytotoxic cyclic peptide from the tunicate Lissoclinum patella. Tetrahedron Lett., 35, 8271-8274. 

Hamada, Y, Shibata, M., and Shioiri, T. (1985) New methods and reagents in organic synthesis. 58. A synthesis of pateHamide A a cytotoxic cyclic peptide from a tunicate. Revision of its proposed structure. Tetrahedron Lett., 26, 6501-6504. 

Chemical data on the family Pleurobranchidae are still very fragmentary. The species Pleurobranchus forskalii (Indonesia) and P. membranaceus (Italy), respectively, yielded keenamide a moderately cytotoxic cyclic peptide (Wesson and Hamann, 1996) and three new polypropionates (membrenones), which permeate the mantle of the mollusk to protect it from predators (Ciavatta et al, 1993). 

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