Orcein und Lackmus

Beecken, Hermann; Gottschalk, E. M.; Gizycki, Ulrich von; Kramer, Horst E. A.; Maaßen, Dieter; Matthies, Hans‐Georg; Musso, Hans; Rathjen, Claus; Záhorszky, U. I.

doi:10.1002/ange.19610732002

Cited by 49 publications

(10 citation statements)

References 36 publications

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“…This work would be further expanded in the 1961 Angewandte Chemie paper [33], which appeared in an English translation in 2003 [31]. As stated in the summary 'Orcein was separated into 14 dyes by partition chromatography.…”

Section: (D) Orcein Purple In Medieval Artmentioning

confidence: 98%

Organic dyes in illuminated manuscripts: a unique cultural and historic record

Melo

Nabais

Guimarães

et al. 2016

Phil. Trans. R. Soc. A.

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Section: (D) Orcein Purple In Medieval Artmentioning

confidence: 98%

Organic dyes in illuminated manuscripts: a unique cultural and historic record

Melo

Nabais

Guimarães

et al. 2016

Phil. Trans. R. Soc. A.

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“…166 Besides being a potential natural product and a precursor to litmus dyes, 167 bisorcinol has later been used as a synthetical precursor to isokotanine. 168 (Q 5RXWH to (+)-Knipholone…”

Section: Dimeric Orcinolmentioning

confidence: 99%

The Lactone Concept: An Efficient Pathway to Axially Chiral Natural Products and Useful Reagents

1999

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$EVWUDFW A highly efficient concept for the stereoselective synthesis of axially chiral biaryl target molecules is presented: the atroposelective ring cleavage of configurationally unstable lactonebridged biaryls. The method has almost no restrictions concerning the substitution pattern, works even for substrates with high steric hindrance at the RUWKR-position(s) of the axis, and allows the optional, atropo-divergent preparation of each atropisomer from the same biaryl lactone precursor and a recycling of the undesired minor product in the sense of a chiral economy. A broad series of successful applications in natural product and ligand syntheses underlines the high value of the method. .H\ ZRUGV axial chirality, biaryl natural products, biaryl ligands and reagents, atropo-divergent synthesis, lactone-bridged biaryls '-BINAP' () R 7

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“…The compounds are derivatives of Orcein (Fig. 2), which, like litmus, is a phenoxazine dye that can be isolated from the lichen Roccella tinctoria [125]. Orcein is a mixture of closely related substances that share a phenoxazine backbone (Fig.…”

Section: Reducing Proteotoxicity By Promoting Fibril Formationmentioning

confidence: 99%

“…During extraction, the conjugated hydroxyl group of the phenoxazine backbone easily hydrolyzes into an amine (Fig. 1) [125]. Mixtures that contain either are also known as Lacmoid or Resorcin blue.…”

Section: Reducing Proteotoxicity By Promoting Fibril Formationmentioning

confidence: 99%

Natural Compounds May Open New Routes to Treatment of Amyloid Diseases

Bieschke

2013

Neurotherapeutics

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Protein misfolding disorders, such as Alzheimer's disease and Parkinson's disease, have in common that a protein accumulates in an insoluble form in the affected tissue. The process of aggregation follows a mechanism of seeded polymerization. Although the toxic species is still not well defined, the process, rather than the end product, of fibril formation is likely the main culprit in amyloid toxicity. These findings suggest that therapeutic strategies directed against the protein misfolding cascade should focus on depleting aggregation intermediates rather than on large fibrillar aggregates. Recent studies involving natural compounds have suggested new intervention strategies. The polyphenol epi-gallocatechine-3-gallate (EGCG), the main polyphenol in Camilla sinensis, binds directly to a large number of proteins that are involved in protein misfolding diseases and inhibits their fibrillization. Instead, it promotes the formation of stable, spherical aggregates. These spherical aggregates are not cytotoxic, have a lower β-sheet content than fibrils, and do not catalyze fibril formation. Correspondingly, epi-gallocatechine-3-gallate remodels amyloid fibrils into aggregates with the same properties. Derivatives of Orcein, which is a phenoxazine dye that can be isolated from the lichen Roccella tinctoria, form a second promising class of natural compounds. They accelerate fibril formation of the Alzheimer's disease-related amyloid-beta peptide. At the same time these compounds deplete oligomeric and protofibrillar forms of the peptide. These compounds may serve as proof-of-principle for the strategies of promoting and redirecting fibril formation. Both may emerge as two promising new therapeutic approaches to intervening into protein misfolding processes.

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Orcein und Lackmus

Cited by 49 publications

References 36 publications

Organic dyes in illuminated manuscripts: a unique cultural and historic record

Organic dyes in illuminated manuscripts: a unique cultural and historic record

The Lactone Concept: An Efficient Pathway to Axially Chiral Natural Products and Useful Reagents

Natural Compounds May Open New Routes to Treatment of Amyloid Diseases

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