| Autor: |
Shaikh AC; Division of Organic Chemistry CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road , Pune 411 008 , India.; Academy of Scientific and Innovative Research (AcSIR) , Ghaziabad 201 002 , India., Varma ME; Savitribai Phule Pune University , Ganeshkhind Road , Pune 411 007 , India.; Bioprospecting Group , Agharkar Research Institute , G. G. Agarkar Road , Pune 411 004 , India., Mule RD; Division of Organic Chemistry CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road , Pune 411 008 , India.; Academy of Scientific and Innovative Research (AcSIR) , Ghaziabad 201 002 , India., Banerjee S; Division of Organic Chemistry CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road , Pune 411 008 , India.; Academy of Scientific and Innovative Research (AcSIR) , Ghaziabad 201 002 , India., Kulkarni PP; Savitribai Phule Pune University , Ganeshkhind Road , Pune 411 007 , India.; Bioprospecting Group , Agharkar Research Institute , G. G. Agarkar Road , Pune 411 004 , India., Patil NT; Department of Chemistry , Indian Institute of Science Education and Research (IISER)-Bhopal , Bhopal 462 066 , India. |
| Abstrakt: |
We recently developed an oxidative intramolecular 1,2-amino-oxygenation reaction, combining gold(I)/gold(III) catalysis, for accessing structurally unique ionic pyridinium-oxazole dyads (PODs) with tunable emission wavelengths. On further investigation, these fluorophores turned out to be potential biomarkers; in particular, the one containing -NMe 2 functionality (NMe 2 -POD) was highly selective for mitochondrial imaging. Of note, because of mitochondria's involvement in early-stage apoptosis and degenerative conditions, tracking the dynamics of mitochondrial morphology with such imaging technology has attracted much interest. Along this line, we wanted to build a library of such PODs which are potential mitochondria trackers. However, Au/Selecfluor, our first-generation catalyst system, suffers from undesired fluorination of electronically rich PODs resulting in an inseparable mixture (1:1) of the PODs and their fluorinated derivatives. In our attempt to search for a better alternative to circumvent this issue, we developed a second-generation approach for the synthesis of PODs by employing Cu(II)/PhI(OAC) 2 -mediated oxidative 1,2-amino-oxygenation of alkynes. Thes newly synthesized PODs exhibit tunable emissions as well as excellent quantum efficiency up to 0.96. Further, this powerful process gives rapid access to a library of NMe 2 -PODs which are potential mitochondrial imaging agents. Out of the library, the randomly chosen POD-3g was studied for cell-imaging experiments which showed high mitochondrial specificity, superior photostability, and appreciable tolerance to microenvironment changes with respect to commercially available MitoTracker green. |
