A likely biogenetic gateway linking 2-aminoimidazolinone metabolites of sponges to proline: spontaneous oxidative conversion of the pyrrole-proline-guanidine pseudo-peptide to dispacamide A.
A new spontaneous oxidative transformation of the associated pyrrole-proline-guanidine to the natural marine pyrrole 2-aminoimidazolinone derivative has been achieved. The sensitive reaction requires air oxygen and the N-acylation of proline by pyrrole-2-carboxylic acid. Proline metabolism and pyrrole 2-aminoimidazole secondary metabolites formation seem to be related and are utilized by sponges under stress conditions for their defense against predators. A plausible stress-induced oxidative chemical pathway that establishes dispacamide derivatives as the forerunners in the biogenetic synthesis of the key pyrrole 2-aminoimidazole oroidin is proposed. The mechanism of the reaction seems to be another development of the known luciferins' chemiluminescent reactions in bioluminescent marine organisms.
Travert
Nathalie
N
Institut de Chimie des Substances Naturelles du CNRS, BP 1, 91198 Gif-sur-Yvette, France.
Al-Mourabit
Ali
A
D000586:Amination; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry; D019791:Guanidine / Q000031:analogs & derivatives*; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D010455:Peptides / Q000737:chemistry*; D011161:Porifera / Q000378:metabolism*; D011392:Proline / Q000031:analogs & derivatives* / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*
D007093:Imidazoles; D010455:Peptides; D011758:Pyrroles; C002986:2-pyrrolecarboxylic acid; C014973:2-aminoimidazole; D011392:Proline; D019791:Guanidine