Verpacamides A-D, a sequence of C11N5 diketopiperazines relating cyclo(Pro-Pro) to cyclo(Pro-Arg), from the marine sponge Axinella vaceleti: Possible biogenetic precursors of pyrrole-2-aminoimidazole alkaloids

• Published in: Organic letters Vol. 8; no. 11; pp. 2421 - 2424
• Main Authors: Vergne, Carine, Boury-Esnault, Nicole, Perez, Thierry, Martin, Marie-Therese, Adeline, Marie-Therese, Dau, Elise Tran Huu, Al-Mourabit, Ali
• Format: Journal Article
• Language: English
• Published: WASHINGTON Amer Chemical Soc 25.05.2006; American Chemical Society
• Subjects: Alkaloids - chemistry; Alkaloids - metabolism; Animals; Axinella - chemistry; Chemical Sciences; Chemistry; Chemistry, Organic; Molecular Structure; Organic chemistry; Oxidation-Reduction; Peptides, Cyclic - chemistry; Physical Sciences; Piperazines - chemistry; Piperazines - isolation & purification; Science & Technology; 2-AMINOIMIDAZOLE; METABOLITES; PYRROLE-IMIDAZOLE ALKALOIDS
• ISSN: 1523-7060; 1523-7052
• DOI: 10.1021/ol0608092

[graphics] Four C11N5 diketopiperazine metabolites named verpacamides A (6), B (7), C (8), and D (9) consisting of a proline- arginine dipeptide skeleton have been isolated from the marine sponge Axinella vaceleti. Verpacamides A-D are a sequence of metabolites showing the transformation of proline and arginine into the oxidized guanidinyl-cyclo(Pro-Pro) 8 and 9. Compounds 6-9 are structurally and chemically related to C11N5 pyrrole-2-aminoimidazole metabolites also isolated from the Axinellidae and Agelasidae families of sponges and exemplified by dispacamide A (4) and dibromophakellin (10).