Rosamines

For uniformity with the stmctures given in the Colourindex the ammonium radical (9) is used for the amino-substituted xanthenes and the keto form for the hydroxy derivatives. The xanthene dyes may be classified into two main groups diphenylmethane derivatives, called pyronines, and triphenylmethane derivatives (eg, (4)), which are mainly phthaleins made from phthaUc anhydride condensations. A third much smaller group of rosamines (9-phenylxanthenes) is prepared from substituted ben2aldehydes. The phthaleins may be further subdivided into the following fluoresceins (hydroxy-substituted) rhodamines (amino-substituted), eg, (6) and mixed hydroxy/amino-substituted. 

Fluorescent Dyestuffs. Very few dyes are of use in making daylight-fluorescent products. Of the dyes discovered up to 1920, only the brilliant ted and salmon dyes of the rhodamine and rosamine classes ate used in fluorescent materials in the 1990s. The first of these, Rhodamine B, was discovered in 1877. Fluorescence excited by both uv and visible light components in daylight was formally recognized as a notable property of certain dyed fabrics by the 1920s (1). 

Fig. 10 Synthetic scheme for the construction of rosamine library using solid-phase combinatorial approach. Average emission values of fluorescent compounds derived from each rosamine moiety are presented below the structure of rosamine moieties. (All the emission wavelengths were obtained in PBS buffer)...

Ahn YH, Lee JS, Chang YT (2007) Combinatorial rosamine library and application to in vivo glutathione probe. J Am Chem Soc 129 4510-4511... 

Recently, another example of a DNA-aptamer that was selected for binding to a small molecule and that was found to accelerate weakly a chemical transformation was reported [ 100]. These aptamers selected to bind to the fluorophor sulforhodamine B with high affinity were also capable of promoting the oxidation of a related molecule, dihydrotetramethyl rosamine, albeit with low efficiency. 

The adduct formed, [(CN)sFeNONRR ] , dissociates to yield a cationic nit-rosamine through either a dissociative or an interchange mechanism, with rate constants on the order of 10 s and 10 s , respectively... 

Ikken, Y., I. Cambero, M. L. Marin, A. Martinez, A. I. Haza, and P. Morales. Antimutagenic effect of fruit and vegetable aqueous extracts against N-nit-rosamines evaluated by the Ames test. J Agr Food Chem 1998 46(12) 5194-5200. 

NT136 Bhide, S. V., J. Kulkarni, U. J. Nair, B. Spiegelhalder, and R. Preussmann. Mutagenicity and carcinogenicity of masheri, a pyrolysed tobacco product, and its content of tobacco-specific nit-rosamines. lARC Sci Publ 1987 (84) 460-462. 

Rosamines. Rosamines are 9-phenylxanthene derivatives prepared front substituted benzaldehydes instead of phthalic anhydride. Sulforhodamine B (Acid Red 52 Cl 45100) is the most important rosamine. 

An acid eosine or acid rhodamine, e g, fast acid eosine, fast acid phloxme, acid rhodamme. acid rosamine, xylene red. brilliant kitone red, sulpho rosazeine, etc Colour unaffected Pyront Class On acidifying the ammOniacal extract fluorescence is not discharged s e o tJ4 ag c rt... 

The mutagenicity of iV-nitrosocyclopropylamino derivatives of type 704 and 705 has been compared with related nitroso compounds It was found that cyclopropylnit-rosamines (705) were much more effective mutagens than the corresponding allyl derivatives . ... 

These bodies, called Rosamines, are obtained by action of benzotrichloride on mono- or dialkyl derivatives of metamidophenol. The new bodies are beautiful red to violet dyestuffs. 

Fig. 17.5 Library of coumarin, Dapoxyl, styryl, hemicyanine, and rosamine scaffolds...

Fig. 17.19 Synthesis of rosamine library on solid support, (a) K2C03, Cu, DMF, 130°C (b) H2S04, 80°C (c) modification for R1 (d) SnCl2, EtOH, 90°C (e) 2-chloro-trityl chloride resin, pyr, CH2C12/DMF (f) R2 Grignard reagent, THF, 62°C (g) 1 %TFA, CH2C12...

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