Lissoclinum bistratum

Foster, M.P. Conception, G.P. Caraan, G.B. Ireland, C.M. (1992) Bistratamides C and D. Two new oxazole-containing cyclic hexapeptides isolated from a Philippine Lissoclinum bistratum ascidian. J. Org. Chem., 57, 6671-5. 

Bistramide A (C H Og) was isolated from the tunicate Lissoclinum bistratum collected at New Caledonia and shown to possess neuro- and cytotoxic activity. Although extensive two-dimensional NMR studies were used, its complete structure remains to be established (238). 

Bistratamides C-J, 381-388, are a group of hexapeptides isolated from the ascidian Lissoclinum bistratum collected from Tablas Island in the Philippines <2003JNP247, 2004CEJ71>. 

Bistramide A and bistratene A are two identical molecules that were isolated from samples of Lissoclinum bistratum collected in New Caledonia and Australia they were pub-hshed one year apart with incorrect structures (Gouiffes et al, 1988a, 1988b Degnan et al, 1989a Watters et al., 1990). However, an original NMR spectroscopic technique was used to determine the exact structure four years... 

It is taken for granted by many researchers that these substances are actually produced by Prochloron, which is symbiotic with Lissoclinum bistratum, but this issue is still poorly understood and subject to controversy (Degnan et al, 1989a Piel, 2004). 

Cyclic peptides and depsipeptides constitute the bulk of the nitrogenous metabolites of didemnid tunicates and several publications have been devoted to them, either wholly or in part, such as Ireland et al. (1989), Davidson (1993) and Lehrer et al. (2003). However, many publications devoted to cyclic peptides of Didemnidae are concerned with only three species, Didemnum molle, Lissoclinum bistratum and Lissoclinum patella, which is the most prolific didemnid as regards cyclic peptides. The two Lissoclinum species were harvested in the Western Pacific (Australia, Fiji, Guam, Indonesia, Palau, Philippines, Pohnpei and Singapore) and Didemnum molle in the Indian Ocean (Comoros, Mozambique). 

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... 

Foster, M.P. and Ireland, C.M. (1993) Nairaiamides A and B two novel di-proline heptapeptides isolated from a Fijian Lissoclinum bistratum ascidian. Tetrahedron Lett., 34, 2871-2874. 

Gouiffes, D Juge, M Grimaud, N Welin, L Sauviat, M.P., Barbin. Y, Laurent, D Roussakis, C Henichart, J.-P., and Verbist, J.-F. (1988a) Bistramide A, a new toxin from the tuochordata Lissoclinum bistratum Sluiter isolation and preliminary characterization. Toxicon. 26,1129-1136. 

Hambley, T.W, Hawkins, C.J., Lavin, M.F., Van den Brenk, A., and Watters, D.J. (1992) Cydoxazohne a cytotoxic cyclic hexapeptide from the asddian Lissoclinum bistratum. Tetrahedron. 48, 341—348. 

You, S. and Kelly, J.W. (2004) Highly efficient biomimetic total synthesis and structural verification of bistratamides E and ( from Lissoclinum bistratum. Chem. Eur. J., 10, 71-75. 

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