Thursday, November 16, 2017 - 11:00am Chemistry Building, Room 400 Organic Seminar Photochemical generation of o-naphthoquinone methides from 3-(hydroxymethyl)-2-naphthol derivatives (NQMPs) has been extensively studied by the research group of Dr. V. V. Popik.1-3 The application of NQMP-based photochemistry has been demonstrated on a variety of substrates. Thus, introduction of NQMP moiety into ion-selective chelators can be considered as a novel approach to control and change on-demand free ion metal concentration. We have recently reported the synthesis, photochemical properties, and Ca2+ release kinetics of a novel photo-cleavable analogue of BAPTA.4 Currently, the work is concentrated on the development of photo-cleavable crown-ethers, the photochemistry of which is also based on generation of NQMP. We are also working on design and synthesis of photoactivatable (caged) fluorescent dyes, nonfluorescent state of which is achieved by incorporation of photolabile protecting groups (PPGs).5 These compounds become fluorescent upon the photo-cleavage of PPG and release of fluorescent dye. Caged fluorescent dyes have received significant attention in multicolor fluorescence microscopy,6 protein dynamics,7 cell lineage studies,8 and visualizing drug delivery. We propose a new platform for the design of caged fluorogenic pH indicators (SNAFR analogs),9-14 which are based on the cyclization of aryl-substituted quinone methides to 9H-xanthenes.15 Also, new caged pH-insensitive fluorescent dyes,16 which are based on the photochemical generation of quinone methide,17 are under development. References 1 S. Arumuqam and V. V. Popik, J. Am. Chem. Soc., 2012, 134, 8408. 2 E. E. Nekongo and V. V. Popik, J. Org. Chem., 2014, 79, 7665. 3 S. Arumugam and V. V. Popik, J. Am. Chem. Soc., 2011, 133, 5573. 4 M. V. Sutton, M. McKinley, R. Kulasekharan and V. V. Popik, Chem. Commun., 2017, 53, 5598. 5 V. N. Belov, C. A. Wurm, V. P. Boyarskiy, S. Jakobs and S. W. Hell, Angew. Chem. Int. Ed. 2010, 49, 3520. 6 N. O’Connor and R. B. Silver, Methods Cell Biol. 2007, 81, 415. 7 S. J. Lord, H. D. Lee, R. Samuel, R. Weber, N. Liu, N. R. Conley, M. A. Thompson, R. J. Twieg and W. E. Moerner, J. Phys. Chem. B 2010, 114 (45), 14157. 8 D. S. Lidke and B. S. Wilson, Trends Cell Biol. 2009, 19, 566. 9 T. J. Rink, R. Y. Tsien and T. Pozzan, J. Cell Biol. 1982, 95, 189. 10 J. E. Whitaker, R. P. Haugland and F. G. Prendergast, Anal. Biochem. 1991, 194, 330. 11 Y. Yang, M. Lowry, X. Xu, J. O. Escobedo, M. Sibrian-Vazquez, L. Wong, C. M. Schowalter, T. J. Jensen, F. R. Fronczek, I. M. Warner and R. M. Strongin, Proc. Natl. Acad. Sci. U. S. A., 2008, 105, 8829. 12 E. Nakata, Y. Nazumi, Y. Yukimachi, Y. Uto, H. Maezawa, T. Hashimoto, Y. Okamoto and H. Hori, Bioorg. Med. Chem. Lett., 2011, 21, 1663. 13 E. Nakata, Y. Yukimachi, Y. Nazumi, Y. Uto, H. Maezawa, T. Hashimoto, Y. Okamoto and H. Hori, Chem. Commun. 2010, 46, 3526. 14 U.C. Saha, K. Dhara, B. Chattopadhyay, S.K. Mandal, S. Mondal, S. Sen, M. Mukherjee, S.V. Smaalen and P. Chattopadhyay, Org. Lett. 2011, 13, 4510. 15 A. Padwa, D. Dehm, T. Oine and G. A. Lee, J. Am. Chem. Soc. 1975, 97, 1837. 16 L. F. Mottram, S. Boonyarattanakalin, R. E. Kovel and B. R. Peterson, Org. Lett. 2006, 8 (4), 581. 17 E. E. Nekongo, P. Bagchi, C. J. Fahrni and V. V. Popik, Org. Biomol. Chem. 2012, 10, 9214.