Chartella papyracea

Unique /3-lactam indole alkaloids, namely, chartellines A (77) (87), B (78), and C (79), methoxydechlorochartelline A (80) (88), and chartella-mides A (81) and B (82) (89), were isolated from a marine bryozoan (Chartella papyracea) collected in North Britanny waters. The structure of chartelline A (77) was confirmed by X-ray analysis, and the absolute... 

Several of the alkaloids from bryozoans can be considered to be indoles—Amathla alternata and Zoobotryon vertlcillatum contain simple indoles while Chartella papyracea, Flustra foliacea and Hinckstnojlus-tra denticulata give rise to more complex polycyclic compounds. 

Scheme 12. Alkaloids from Chartella papyracea. At left, chartelline A, B, C, and methoxy-dechlo-rochaitelline A. At right chartellamide A and B.

The securines, securamines, chartellines, and chartellamides are members of a structurally unique class of natural products isolated from the bryozoa Chartella papyracea and Securiflustra securifrons by Christophersen and coworkers [65-69] (Fig. 7). Chartellines represent a small family of marine-derived, architecturally unique alkaloids that include chartelline A, chartelline B, and chartelline C, which only differ in the number and position of bromines. Chartelline C (173) is composed of indolenine, imidazole, and jS-lactam heterocycles arrayed in a dense, Ji-stacking framework that poses an obvious challenge for its synthesis [70, 71], Though numerous efforts have been made towards chartelline C (173), rally Baran and coworkers have reported its synthesis [70, 71]. 

Anthoni U, Chevolot L, Larsen C, Nielsen PH, Christophersen C (1987) Marine alkaloids. 12. Chartellines, halogenated (3-lactam alkaloids from the marine Bryozoan Chartella papyracea. J Org Chem 52 4709 712... 

Chevolot L, Chevolot AM, Larsen C, Anthoni U, Christophersen C (1985) Charlelline A a pentahalogenated alkaloid from the marine Bryozoan Chartella papyracea. J Am Chem Soc 107 4542-4543... 

Anthoni, U., Chevolot, L., Larsen, C., Nielsen, P. H., Christophersen, C. Marine alkaloid s. 12. chartellines, halogenated y0-lactam alkaloids from the marine bryozoan Chartella papyracea. J. Org. Chem. 1987, 52, 4709-4712. 

Formally related to seciuamines but containing a P-lactam cycle by transposition of the physostigmine system, charteUamides and chartellines were aU isolated from the species Chartella papyracea harvested in Rosc-off, France (Chevolot et al., 1985 Anthoni et al., 1987a, 1987b). AU of these derivatives have some antibacterial activity, and are probably used by the animal colony as defense substances. 

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