92642-09-6Relevant articles and documents
In-vitro and In-vivo Photocatalytic Cancer Therapy with Biocompatible Iridium(III) Photocatalysts
Huang, Can,Liang, Chao,Sadhukhan, Tumpa,Banerjee, Samya,Fan, Zhongxian,Li, Tingxuan,Zhu, Zilin,Zhang, Pingyu,Raghavachari, Krishnan,Huang, Huaiyi
, p. 9474 - 9479 (2021)
Photocatalytic anticancer profile of a IrIII photocatalyst (Ir3) with strong light absorption, high turnover frequency, and excellent biocompatibility is reported. Ir3 showed selective photo-cytotoxicity against cisplatin- and sorafenib-resistant cell lines while remaining dormant to normal cell lines in the dark. Ir3 exhibited excellent photo-catalytic oxidation of cellular co-enzyme, the reduced nicotinamide adenine dinucleotide phosphate (NADPH), and amino acids via a single electron transfer mechanism. The photo-induced intracellular redox imbalance and change in mitochondrial membrane potential resulted in necrosis and apoptosis of cancer cells. Importantly, Ir3 exhibited high biocompatibility and photo-catalytic anticancer efficiency as evident from in vivo zebrafish and mouse cancer models. To the best of our knowledge, Ir3 is the first IrIII based photocatalyst with such a high biocompatibility and photocatalytic anticancer therapeutic effect.
Multivalent Antibiotics via Metal Complexes: Potent Divalent Vancomycins against Vancomycin-Resistant Enterococci
Xing, Bengang,Yu, Chun-Wing,Ho, Pak-Leung,Chow, Kin-Hung,Cheung, Terence,Gu, Hongwei,Cai, Zongwei,Xu, Bing
, p. 4904 - 4909 (2003)
Dimers of vancomycin (Van), linked by a rigid metal complex, [Pt(en)(H 2O)2]2+, exhibit potent activities (MIC ~0.8 μg/mL, ~720 times more potent than that of Van itself) against vancomycin-resistant enterococci (VRE). The result suggests that combining metal complexation and receptor/ligand interaction offers a useful method to construct multivalent inhibitors.
Facile synthesis of new fullerene-Ru(bpy)3 dyads bearing phosphonate groups for hybrid organic-inorganic materials
Brunet, Ernesto,Alonso, Marina,Quintana, Ma Carmen,Juanes, Olga,Rodríguez-Ubis, Juan-Carlos
, p. 3739 - 3743 (2007)
Fullerene reacted with mono- and diphosphonate-bearing bipyridines by way of Bingel-type reactions to give adducts which were easily transformed in the corresponding dyads by forming Ru(bpy)3 complexes. Electrochemical measurements and the observation of heavy quenching of the Ru(bpy)3 luminescence manifested strong interactions between the active moieties. Attempts to include the dyads into inorganic matrices derived from zirconium phosphate are reported.
Formation and transmetalation mechanisms of homo- and heterometallic (Fe/Zn) trinuclear triple-stranded side-by-side helicates
Akhuli, Bidyut,Cera, Luca,Jana, Barun,Saha, Subrata,Schalley, Christoph A.,Ghosh, Pradyut
, p. 4231 - 4242 (2015)
A novel linear hybrid tris-bidentate neutral ligand having 2,2′-bipyridine and two terminal triazolylpyridine coordination sites (L) was efficiently synthesized and explored in the synthesis of trinuclear triple-stranded homometallic side-by-side helicates L3Fe3(OTf)6 (1) and L3Zn3(OTf)6 (2), in which the three metal centers display alternating λ and Δ configurations. Selective formation of the analogous heterometallic side-by-side helicate L3Fe2Zn(OTf)6 (3) was achieved from a mixture of L, Fe(CH3CN)2(OTf)2, and Zn(OTf)2 (1:1:1) in acetonitrile at room temperature. Various analytical techniques, i.e., single-crystal X-ray diffraction and NMR and UV/vis spectroscopy, were used to elucidate the sequence of the metal atoms within the heterometallic helicate, with the Zn2+ at the central position. The formation of 3 was also achieved starting from either L3Zn3(OTf)6 or L3Fe3(OTf)6 by adding Fe(CH3CN)2(OTf)2 or Zn(OTf)2, respectively. ESI-MS and 1H NMR studies elucidated different transmetalation mechanisms for the two cases: While a Zn2+-to-Fe2+ transmetalation occurs by the stepwise exchange of single ions on the helicate L3Zn3(OTf)6 at room temperature, this mechanism is almost inoperative for the Fe2+-to-Zn2+ transmetalation in L3Fe3(OTf)6, which is kinetically trapped at room temperature. In contrast, dissociation of L3Fe3(OTf)6 at higher temperature is required, followed by reassembly to give L3Fe2Zn(OTf)6. The reassembly follows an interesting mechanistic pathway when an excess of Zn(OTf)2 is present in solution: First, L3Zn3(OTf)6 forms as the high-temperature thermodynamic product, which is then slowly converted into the thermodynamic heterometallic L3Fe2Zn(OTf)6 product at room temperature. The temperature-dependent equilibrium shift is traced back to significant entropy differences resulting from an enhancement of the thermal motion of the ligands at high temperature, which destabilize the octahedral iron terminal complex and select zinc in a more stable tetrahedral geometry.
Macrocycles with switchable exo/endo metal binding sites
Tian, Lei-Lei,Wang, Chun,Dawn, Sandipan,Smith, Mark D.,Krause, Jeanette A.,Shimizu, Linda S.
, p. 17620 - 17629 (2009)
We report herein the synthesis and metal complexation properties of two macrocyclic hosts that contain two 2,2′-bipyridines and two urea groups. These hosts take advantage of the conformationally mobile 5,5′-positions of the bipyridines to give metal binding sites that are dynamic. By simple bond rotation, these hosts can exchange an interior (endo) situated metal binding site for an exterior (exo) binding site. We examine the solid-state structures of the two free hosts and two coordination complexes ([Cd(host 1)(H 2O)(NO3)2] and [Ag2(host 2)](SO 3CF3)2) using X-ray crystallography. Analysis of these crystal structures suggests that the bipyridine groups within the hosts are able to rotate to access multiple conformations including the desired exo and endo conformations. We also investigate the binding affinity of these new ligands in solution by UV-vis titrations with a series of metal nitrate salts (Ag, Cd, Zn, Ni, Mn, Fe, Co, Cr, and Cu) to afford discrete metal complexes. Some complexes showed a slow subsequent assembly to yield coordination polymers. Thus, these systems may afford unique insights into the process of metal organic framework formation.
Stapling monomeric GCN4 peptides allows for DNA binding and enhanced cellular uptake
Iyer, Abhishek,Van Lysebetten, Dorien,Ruiz García, Yara,Louage, Benoit,De Geest, Bruno G.,Madder, Annemieke
, p. 3856 - 3862 (2015)
The basic DNA recognition region of the GCN4 protein comprising 23 amino acids has been modified to contain two optimally positioned cysteines which have been linked and stapled using cross-linkers of suitable lengths. This results in stapled peptides wit
PH-controlled crystal growth of copper/gemini surfactant complexes with bipyridine groups
Yao, Junyao,Chen, Qibin,Sheng, Yujie,Kai, Aiting,Liu, Honglai
, p. 5835 - 5843 (2017)
The pH-controlled crystal growth of two complexes with different coordination modes, derived from gemini surfactant molecules with a bipyridyl spacer (12Bpy) and metal copper ions (Cu2+) is presented in this work. Such crystalline forms obtained in appropriate pH ranges exhibit dissimilar morphologies, colors and crystalline structures. Under weak acidic conditions with a slightly higher pH (>4.3), blue grain crystals, made from dihydroxo-bridged binuclear complexes with a square pyramidal coordination mode, are formed, whereas under slightly stronger acidic conditions (pH 3.8 in this work), green crystals with mononuclear complexes with a distorted trigonal bipyramidal geometry are readily fabricated, and meanwhile the blue crystals are completely inhibited. In particular, these two crystals concomitantly existed in an intermediate pH range of 3.8-4.3. We suggest a fivefold coordinated Cu(ii)/12Bpy complex with a 1 : 1 metal-ligand ratio and three hydrated water ligands and a pH-controlled crystal growth mechanism on the basis of UV-vis spectra and density functional theory (DFT) calculations. Our findings indicate that pH adjustment is a straightforward and efficient way to control the crystal growth, having potential application in the preparation of smart and multifunctional materials.
Luminescent pH Sensors Based on Di(2,2'-bipyridyl)(5,5'-diaminomethyl-2,2'-bipyridyl)ruthenium(II) Complexes
Grigg, Ronald,Norbert, W. D. J. Amilaprasadh
, p. 1300 - 1302 (1992)
Luminescent pH sensors based on II(bpy)3>2+ (bpy = 2,2'-bipyridyl) display proton assisted retrieval of luminescence in 1b-d and proton assisted quenching of luminescence in 1a (both due to photoinduced electron transfer) and prot
Naphthalene containing amino-ether macrocycle based Cu(ii) templated [2]pseudorotaxanes and OFF/ON fluorescence switching: Via axle substitution
Bej, Somnath,Ghosh, Pradyut
, p. 13408 - 13418 (2018)
A new naphthalene containing macrocycle, NaphMC, and a new fluorophoric bidentate linear axle derivative of 5,5′-dimethyl-2,2′-bipyridine (L3) along with two other ligands 1,10-phenanthroline (L1) and 5,5′-dimethyl-2,2′-bipyridine (L2) are explored towards the synthesis of Cu(ii) templated [2]pseudorotaxanes. All ternary complexes are well characterized by ESI-MS, UV/Vis, EPR spectroscopy, elemental analysis and emission spectroscopic studies. Single crystal X-ray diffraction studies confirm the geometry around the Cu(ii) center as a distorted trigonal bipyramid via the contribution of [3 + 2] orthogonal motifs of the wheel (NaphMC) and the bidentate chelating ligands L1 and L2 in the cases of pseudorotaxanes, CuPR1 and CuPR2, respectively. Furthermore, the fluorescence "OFF" state of the fluorophoric axle L3 is achieved via threading it to the Cu(ii) complex of NaphMC, whereas fluorescence switching "ON" is demonstrated by the substitution of L3 of CuPR3 with a stronger chelating ligand L1.
Reversible water uptake by a porous molecular crystal from metal complex of gemini surfactant
Yao, Junyao,Chen, Qibin,Sheng, Yujie,Kai, Aiting,Liu, Honglai
, p. 802 - 810 (2017)
We present a novel porous molecular crystal (PMC) constructed using metal complexes, which shows a striking feature, namely that such a crystal exhibits a reversible transition in the crystal structure when subjected to water removal/uptake cycles. It was found that the dehydrated crystal adsorbed a given quantity of water, that is, each complex assembling block, derived from two gemini surfactant molecules with a bipyridyl spacer and two copper ions (Cu2+) coordinated, stuck to 10 molecules of water. Also, the water included in crystals might generate a unique two-dimensional (2D) hydrogen bond network, including metal-ligand complex units, counter ions and crystalline water. Specially, the crystalline structure was not destroyed upon desolvation, which is ascribed to the metal ion introduced as well as the counter ion (Br?) providing additional electrostatic interactions and hydrogen bonds. Our findings indicate that the introduction of metal ions may provide an alternative to the common weak interactions when designing PMCs. In addition, this crystal material is sensitive to moisture, extending the scope of such a gemini species for potential applications in chemical sensors and in humid environments.