Luminescent Polypyridinerhenium(I) Bis‐Biotin Complexes as Crosslinkers for Avidin

Abstract

Two novel luminescent polypyridinerhenium(I) bis-biotin com-(2)} and their biotinfree counterpart [N ∧ N = 4,4Ј-bis(n-butylaminocarbonyl)-2,2Ј-bipyridine, bpyC4 (3)] have been synthesized and characterized. Upon irradiation, all the complexes exhibited triplet metal-to-ligand charge-transfer ( 3 MLCT) emission in fluid solutions at room temperature and alcohol glass at 77 K. The avidin-binding properties of the bis-biotin complexes 1 and 2 have been studied by 4Ј-hydroxyazobenzene-2-carboxylic

Underestimated Potential of Organometallic Rhenium Complexes as Anticancer Agents

“…All compounds screened for cytotoxicity were indeed imaged in the cytoplasm. 28,32,33,39,51 When co-localization experiments were performed on Re organometallic complexes 7i and 9f ( Figure 1A), predominately mitochondrial (up to 80%) localization was reported. 39 A non-negligible percentage of endosomal accumulation (about 20%) has also been detected for compound 7i 39 As a note of caution, although fluorescent microscopy imaging is an important tool in the investigation of the cellular behavior of Re organometallic complexes, their luminescence can sometimes be quenched in cells.…”

“…Their anti-proliferative activity reached or even exceeded the one of cisplatin on various human cancer cell lines. 28,30,32,39,40,45,49,51 The cytotoxicity of the compounds generally increased with lipophilicity, 32,33,39,49,51 most probably due to an improved cellular uptake. Re(I) complexes 9 ( Figure 1A) derivatized with a fluorous pendant were the only exception to this trend.…”

Re(I) carbonyl complexes: Multimodal platforms for inorganic chemical biology

“…This is generally done by tuning the structure of the N^N ligand, since it is involved in the MLCT. Two families of ligand have been particularly explored: (i) polypyridyl ligands, mostly derived from 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) [19][20][21][23][24][25][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] and (ii) bis-quinoline and its derivatives, e.g. bis(phenanthridinylmethyl)amine (bpm) [22,[43][44][45].…”

“…Additionally, compound 3 ( Figure 3) was found to be internalized only in dead or damaged cells, being thus a potential cell-death marker. Examples of biotinylated Re(CO) 3 polypyridyl complexes (compounds 4, 5, Figure 3) were found to localize in lipophilic compartments like Golgi apparatus or endoplasmic reticulum [37,52].…”

Organometallic complexes of transition metals in luminescent cell imaging applications

“…substituents, including biologically relevant units such as biotin, and amine reactive units (e.g. thioureas) have been appended to both the bipyridine and pyridine ligands and in depth studies of uptake and cytotoxicity performed in addition to live cell imaging [32,33]. A responsive rhenium complex which changes its luminescence in the presence of certain metal ions 13 has been applied as an intracellular agent for the imaging of zinc and cadmium [34].…”