BODIPY based realtime, reversible and targeted fluorescent probes for biothiol imaging in living cells.

Real-time live cell imaging and quantification of biothiol dynamics are important for understanding pathophysiological processes. However, the design and synthesis of rational probes that have reversible and real-time capabilities is still challenging. In this work, we have prepared boron-dipyrrolemethene (BODIPY) based fluorescent molecules as ratiometric probes that allow the real-time biothiol dynamics to be observed in living cells. The Michael reaction between α-formyl-BODIPY (BOD-JQ) and GSH exhibited a reversible fluorogenic mechanism with fluorescent emission shifting from 592 nm to 544 nm with t1/2 = 16 ms. In particular, we showed that the probes with targeting agents are capable of detecting biothiols in mitochondria and the endoplasmic reticulum (ER) with high temporal resolution.

Twelve-Armed Hexaphenylbenzene-Based Giant Supramolecular Framework for Entrapping Guest Molecules.

Host-guest chemistry is a functional model in supramolecular chemistry for understanding specific process occurring in biological systems. Herein, we describe a rationally designed giant multiarmed hexaphenylbenzene (HPB)-based supramolecular frameworks which encapsulate a variety of guest molecules in the voids of their crystal lattice through the cooperative interplay of multivalency, noncovalent forces and backbone rigidity. In this connection, pseudo-axially substituted twelve-armed hexaphenylbenzene was synthesized and its molecular entrapping nature was studied by varying number of H-bond donor-acceptor sites in the arms. The per-methyl esterified HPB acted as a cavitand to include nonpolar and polar aprotic guests in its crystal structure via C-H⋅⋅⋅π, C-H⋅⋅⋅O and C-H⋅⋅⋅N interactions. The corresponding amidated HPB showed unprecedented inclusion of ammonia and segregation of the guest molecules according to their polarity in the lattice. Furthermore, this molecular entrapping system has been used to obtain the crystal structure of a hitherto unproven 2-azaallenium intermediate, which had been proposed to be involved in aminomethylation of activated arenes.