A review. Nature provides a primary source of leads for the design of π-conjugated org. chromophores and other functional mol. systems useful for mol. recognition, light harvesting, photoconversion, and other technol. applications. In this Account, we draw attention to a unique group of naturally occurring heterocyclic compds., the 2H-1,4-benzothiazines and related benzothiazole derivs. Derived from tyrosine and cysteine, these mols. arise from a mutation-induced deviation of the melanin pathway to provide the core structure of the red human hair pigments pheomelanins. Since the elucidation of the biosynthetic pathway of pheomelanins in the 1960s, researchers have focused on 1,4-benzothiazines and red hair pigments. Not only do these mols. have interesting photochem. and mol. recognition properties, they also have compelling biomedical significance. Numerous studies have linked higher levels of pheomelanins and mutations in the pathways that produce these pigments in individuals with red hair and fair skin with an increased sensitivity to UV light and a higher susceptibility to melanoma and other skin cancers. Prompted by new data about the structure and photochem. of the bibenzothiazine system, this Account highlights the chem. of benzothiazines in red-haired individuals as a novel source of inspiration in the quest for innovative scaffolds and biomimetic functional systems. Model studies have gradually shed light on a no. of remarkable phys. and chem. properties of benzothiazine-based systems. Bibenzothiazine is a robust visible chromophore that combines photochromism and acidichromism. Benzothiazine-based polymers (synthetic pheomelanins) show remarkable photochem., paramagnetic, and redox cycling properties. Biomimetic or synthetic manipulations of the benzothiazine systems, through decarboxylation pathways controlled by metal ions or unusually facile ring-contraction processes, can produce a diverse set of mol. scaffolds.
Red Hair Benzothiazines and Benzothiazoles: Mutation-Inspired Chemistry in the Quest for Functionality
D'ISCHIA, MARCO
2013
Abstract
A review. Nature provides a primary source of leads for the design of π-conjugated org. chromophores and other functional mol. systems useful for mol. recognition, light harvesting, photoconversion, and other technol. applications. In this Account, we draw attention to a unique group of naturally occurring heterocyclic compds., the 2H-1,4-benzothiazines and related benzothiazole derivs. Derived from tyrosine and cysteine, these mols. arise from a mutation-induced deviation of the melanin pathway to provide the core structure of the red human hair pigments pheomelanins. Since the elucidation of the biosynthetic pathway of pheomelanins in the 1960s, researchers have focused on 1,4-benzothiazines and red hair pigments. Not only do these mols. have interesting photochem. and mol. recognition properties, they also have compelling biomedical significance. Numerous studies have linked higher levels of pheomelanins and mutations in the pathways that produce these pigments in individuals with red hair and fair skin with an increased sensitivity to UV light and a higher susceptibility to melanoma and other skin cancers. Prompted by new data about the structure and photochem. of the bibenzothiazine system, this Account highlights the chem. of benzothiazines in red-haired individuals as a novel source of inspiration in the quest for innovative scaffolds and biomimetic functional systems. Model studies have gradually shed light on a no. of remarkable phys. and chem. properties of benzothiazine-based systems. Bibenzothiazine is a robust visible chromophore that combines photochromism and acidichromism. Benzothiazine-based polymers (synthetic pheomelanins) show remarkable photochem., paramagnetic, and redox cycling properties. Biomimetic or synthetic manipulations of the benzothiazine systems, through decarboxylation pathways controlled by metal ions or unusually facile ring-contraction processes, can produce a diverse set of mol. scaffolds.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
