Dispacamides

Cafieri F, Fattorusso E, Mangoni A, Taglialatela-Scafati O (1996) Dispacamides, Anti-Histamine Alkaloids from Caribbean Agelas Sponges. Tetrahedron Lett 37 3587... 

Different molecular mechanisms have been separately postulated for dibromo-phakellin [74], dibromoagelaspongin [91], agelastatin [92], mauritiamine [88], and palau amine [78]. A1 Mourabit and Potier proposed a universal chemical pathway, starting from the simple precursors 101 and 140 and leading to over 60 pyrrole-imidazole alkaloids [80]. A new biomimetic spontaneous conversion of proline to 2-aminoimidazolinone derivatives using a self-catalyzed intramolecular transamination reaction together with peroxide dismutation as key step has been described [166]. This work has pointed to dispacamide A as the forerunner of oroidin and compounds 101 and 140 as probable hydrolysis products of oroidin and not the precursors. In this... 

In has been hypothesized that this portion of the molecule could interact with hydrophobic groups in the receptor zone, so that the insertion of a polar group achieves the effect of making this interaction worse [15]. The 9-methoxy derivative of dispacamide B (8), isolated as a racemate from the Mediterranean sponge Axinella verrucosa [16], displayed neuroprotective activity against the agonist serotonin in vitro, with a potential to treat psychosis, different phobia and mood fluctuation disorders. 

Cafieri, F., Fattorusso, E., Mangoni, A., Taglialatela-Scafati, O., (1996). Dispacamides, anti-histamine alkaloids from Caribbean Agelas sponges. Tetrahedron Lett. 7, 3587-3590. 

Scheme 9.12 Total syntheses of oroidin, hymenidin, dispacamide, monobromodispacamide, and ageladine A...

Ando N, Terashima S (2010) A novel synthesis of the 2-amino-lH-imidazol-4-carbaldehyde derivatives and its application to the efficient synthesis of 2-aminoimidazole alkaloids, oroidin, hymenidin, dispacamide, monobromodispacamide, and ageladine A. Tetrahedron 66 6224-6237... 

Home was able to provide support for the biosynthetic hypothesis that mauritiamine (197) results from dimerization of an oroidin-like species. Upon examination of the natural product stmcture, it appears to be the union of oroidin (25) and dispacamide (196) (Scheme 13.34). Home was able to dimerize vinyl aminoimidazole 26 under oxidative conditions to provide the core of mauritiamine (199) [130]. After installation of the dibromopyrroles via acylation, the natural product was realized in six steps from ornithine methyl ester (198), without the need for PGs. 

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