Synthesis of dimeric analogs of adenophostin A that potently evoke Ca2+ release through IP3 receptors.

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are tetrameric intracellular channels through which many extracellular stimuli initiate the Ca2+ signals that regulate diverse cellular responses. There is considerable interest in developing novel ligands of IP3R. Adenophostin A (AdA) is a potent agonist of IP3R and since some dimeric analogs of IP3R ligands are more potent than the corresponding monomer; we considered whether dimeric AdA analogs might provide agonists with increased potency. We previously synthesized traizolophostin, in which a simple triazole replaced the adenine of AdA, and showed it to be equipotent to AdA. Here, we used click chemistry to synthesize four homodimeric analogs of triazolophostin, connected by oligoethylene glycol chains of different lengths. We evaluated the potency of these analogs to release Ca2+ through type 1 IP3R and established that the newly synthesized dimers are equipotent to AdA and triazolophostin.University Grants Commission India (Senior Research Fellowship), Department of Science and Technology India (Swarnajayanti Fellowship, Ramanujan Fellowship), Wellcome TrustThis is the author accepted manuscript. The final version is available from The Royal Society of Chemistry via http://dx.doi.org/10.1039/c6ra19413

Studies on Synthesis, Structure, and Properties of Metal Coordinated N-Confused Calixphyrin Analogues.

主1工学_物質創造工

Piperazine Bridged Thianorrole Dimer

Oxidative cyclization of open chain thiabilanes yielded the first examples of unique piperazine bridged thianorrole dimers instead of the expected thianorrole monomer. In the thianorrole dimer, the two thianorrole monomeric units are linked via two direct pyrrole C–C bonds by involving the inverted pyrrole and adjacent pyrrole rings of each thianorrole macrocycle and generate a six-membered piperazine ring that bridges the two thianorrole macrocycles. The spectral studies indicated that the thianorrole dimers are nonaromatic in nature

Singly and Doubly N-Confused Calix [4] phyrin Organoplatinum (II) Complexes as Near-IR Triplet Sensitizers

Organoplatinum(II) complexes of calix[4]phyrin analogues, singly N-confused calix[4]phyrin (Pt-2), and doubly N-confused calix[4]phyrin (Pt-3), were synthesized and characterized. The explicit structures of these organoplatinum(II) complexes were elucidated by single-crystal X-ray diffraction and spectroscopic studies. The introduction of N-confused pyrrole rings to the parent calix[4]phyrin scaffold was found to have profound effects on the photophysical properties, such as the bathochromic shifts of both the absorption and phosphorescence maxima. The triplet excited state properties of these platinum complexes were analyzed by DFT calculations at the B3LYP level. The organoplatinum(II) complexes derived from the deformed scaffolds can serve as potent triplet sensitizers for singlet oxygen generation under aerobic conditions

Singly and Doubly N‑Confused Calix[4]phyrin Organoplatinum(II) Complexes as Near-IR Triplet Sensitizers

Organoplatinum­(II) complexes of calix[4]­phyrin analogues, singly N-confused calix[4]­phyrin (<b>Pt-2</b>), and doubly N-confused calix[4]­phyrin (<b>Pt-3</b>), were synthesized and characterized. The explicit structures of these organoplatinum­(II) complexes were elucidated by single-crystal X-ray diffraction and spectroscopic studies. The introduction of N-confused pyrrole rings to the parent calix[4]­phyrin scaffold was found to have profound effects on the photophysical properties, such as the bathochromic shifts of both the absorption and phosphorescence maxima. The triplet excited state properties of these platinum complexes were analyzed by DFT calculations at the B3LYP level. The organoplatinum­(II) complexes derived from the deformed scaffolds can serve as potent triplet sensitizers for singlet oxygen generation under aerobic conditions