The marine sponge Agelas citrina as a source of the new pyrrole–imidazole alkaloids citrinamines A–D and N-methylagelongine
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چکیده
The chemical investigation of the Caribbean sponge Agelas citrina revealed four new pyrrole-imidazole alkaloids (PIAs), the citrinamines A-D (1-4) and the bromopyrrole alkaloid N-methylagelongine (5). All citrinamines are dimers of hymenidin (6) which was also isolated from this sponge as the major metabolite. Citrinamines A (1) and B (2) are derivatives of the PIA dimer mauritiamine (7), whereas citrinamine C (3) is derived from the PIA dimer nagelamide B (8). Citrinamine D (4) shows an uncommon linkage between the imidazole rings of both monomeric units as it is only observed in the benzocyclobutane ring moiety of benzosceptrins A-C (9-11). Compound 5 is the N-methyl derivative of agelongine (12) which consist of a pyridinium ring and an ester linkage instead of the aminoimidazole moiety and the common amide bond in PIAs.
منابع مشابه
Synthesis of the Pyrrole-Imidazole Alkaloid Sventrin from the Marine Sponge Agelas sventres
Gregor Breckle, Kurt Polborn, and Thomas Lindel Ludwig-Maximilians-Universität München, Department of Chemistry, Butenandtstr. 5Ð13, D-81377 Munich, Germany Reprint requests to Prof. Dr. Th. Lindel. Fax int: +(0)89/2180-7-7734. E-mail: [email protected] Z. Naturforsch. 58b, 451Ð456 2003; received February 17, 2003 The marine pyrrole-imidazole alkaloid sventrin (1) and the hither...
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