Most common used oxazine dye compounds.
The two oxazine dyes were chosen because of the excellent ..
Among the many other methods of dye-stuff synthesis, de pendent upon the linking together of hydro-carbon nuclei into more complex molecules, may be mentioned the production of synthetic indigo. The raw materials in this case are aniline and chloro-acetic acid, which upon condensation give phenylglycine. This, upon fusion with caustic alkali, produces indoxyl and by air oxidation indigo : The most complex molecular structures are those possessed by the vat dyes of the anthraquinone class. These are obtained by the linking together of two or more anthraquinone residues or by the fusion of these residues with other groups in such a way as to produce new carbon rings. The very fast indanthrene blue RS or duranthrene blue is obtained by heating (3-aminoanthra quinone with caustic alkalis and subsequent oxidation by air. The change is thus represented : This method of dye-stuff synthesis has proved capable of wide application and is very suitable for technical employment, since it can be effected in cold aqueous solution, gives almost theo retical yields and allows of any required substituent being intro duced in prearranged position into the final dye-stuff. When applied to diamino-compounds such as benzidine, it gives rise to dyes containing three hydro-carbon residues (disazo-dyes), such as Congo red : Disazo-dye-stuffs of another type are obtained by coupling diazo compounds with primary monoamino-derivatives, again diazo tizing the free amino-groups in these products and recoupling the diazo-compounds with suitable hydroxy or amino-derivatives. For example : i3y applying a similar process to diamines, and also by making A still more complex example is the dye-stuff caledon jade green which has the structure : It is obtained from anthraquinone, by first condensing with gly cerine, then fusing with caustic soda, oxidizing the product (dibenzanthrone), and finally introducing methyl groups in place of two hydrogen atoms. While initially all the alizarine or anthra quinone dyes were synthesized from anthracene, recently with the cheapening of phthalic anhydride, these dyes are also made by condensation of phthalic anhydride with benzene or its derivatives.
Formation of oxazine dye by photochemical reaction of …
As Alzheimer's disease pathogenesis is associated with the formation of insoluble aggregates of amyloid beta-peptide, approaches allowing the direct, noninvasive visualization of plaque growth in vivo would be beneficial for biomedical research. Here we describe the synthesis and characterization of the near-infrared fluorescence oxazine dye AOI987, which readily penetrates the intact blood-brain barrier and binds to amyloid plaques. Using near-infrared fluorescence imaging, we demonstrated specific interaction of AOI987 with amyloid plaques in APP23 transgenic mice in vivo, as confirmed by postmortem analysis of brain slices. Quantitative analysis revealed increasing fluorescence signal intensity with increasing plaque load of the animals, and significant binding of AOI987 was observed for APP23 transgenic mice aged 9 months and older. Thus, AOI987 is an attractive probe to noninvasively monitor disease progression in animal models of Alzheimer disease and to evaluate effects of potential Alzheimer disease drugs on the plaque load.