02414nas a2200205   4500008004100000022001400041245009600055210006900151260000900220300001400229490000700243520169500250100002201945700002401967700002301991700002302014700002502037700002102062856012502083       2019                        eng d  a0022-326300aIonic pyridinium-oxazole dyads: design, synthesis, and application in mitochondrial imaging0 aIonic pyridiniumoxazole dyads design synthesis and application i  cFEB   a1766-17770 v843 a<p>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 -NMe2 functionality (NMe2-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 NMe2-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.</p>
1 aShaikh, Aslam, C.1 aVarma, Mokshada, E.1 aMule, Ravindra, D.1 aBanerjee, Somsuvra1 aKulkarni, Prasad, P.1 aPatil, Nitin, T.  uhttps://library.ncl.res.in/content/ionic-pyridinium-oxazole-dyads-design-synthesis-and-application-mitochondrial-imaging