title: Cyclic structural motifs in 5,6-dihydroxyindole polymerization uncovered: biomimetic modular buildup of a unique five-membered macrocycle.
abstract: An unprecedented 5,6-dihydroxyindole macrocycle (4) featuring a rigid twisted backbone was obtained by biomimetic oxidative cross-coupling of the 2,2'-biindole 2 and triindole 3. A putative reaction intermediate, 2-quinone, was detected and characterized by pulse radiolysis and DFT calculations. Discovery of 4 indirectly supports for the first time theoretically predicted cyclic structural motifs as potential eumelanin building blocks.
authors.affiliation: Department of Organic Chemistry and Biochemistry, University of Naples Federico II, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Arzillo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pezzella
authors.forename: Orlando
authors.initials: O
authors.lastname: Crescenzi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Napolitano
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Land
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barone
authors.forename: Marco
authors.initials: M
authors.lastname: d'Ischia
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry*
chemical_list: D007211:Indoles; D047028:Macrocyclic Compounds; D011108:Polymers; C033871:5,6-dihydroxyindole