Biomimetic studies towards the total synthesis of highly complex araiosamines

Araiosamines are among the most complex indole alkaloids isolated from marine environments to date [1]. Indeed, the fascinating structures of several araiosamines were disclosed in 2011 (see the structure of araiosamine C) from a marine sponge (Clathria araiosa) [2]. Their structures reveal an original assembly of tryptophane-derived reactive building blocks and guanidine. Based on biosynthetic considerations, several cascades of reactions are studied involving simple indole-acetaldehydes and guanidine itself in order to better understand how such molecular architectures can arise in Nature [3]. Metabolomic tools appear appropriate for such approaches. Assemblies of the starting units give rise to interesting guanidine heterocycles.

Keywords: Araiosamine, alkaloids, guanidine.

References:

[1] Berlinck RGS, Burtoloso AC, Trindale-Silva AE, Romminger S, Morais RP, Bandeira K, Mizumo CM. The chemistry and biology of organic guanidine derivatives. Nat Prod Rep 2010; 27: 1871 – 1907

[2] Wei X, Henriksen NM, Skalicky JJ, Harper MK, Cheatham TE, Ireland CM, Van Wagoner RM. Araiosamines A-D: Tris-bromoindole Cyclic Guanidine Alkaloids from the Marine Sponge Clathria (Thalysias) araiosa. J Org Chem 2011; 76: 5515 – 5523

[3] Genta-Jouve G, Cachet N, Holderith S, Obershänli F, Teyssié JL, Jeffree R, Al Mourabit A, Thomas OP. New insight into marine alkaloid metabolic pathways: revisiting oroidin biosynthesis. ChemBioChem 2011; 12: 2298 – 2301