2752-17-2Relevant academic research and scientific papers
A New Manganese(III) Complex from Bis(5-methylsalicylaldehyde)-3-oxapentane-1,5-diamine: Synthesis, Characterization, Antioxidant Activity and Luminescence
Wu, Huilu,Wang, Cuiping,Wang, Fei,Peng, Hongping,Zhang, Han,Bai, Yuchen
, p. 1028 - 1034 (2015)
A Schiff base ligand bis(5-methylsalicylaldehyde)-3-oxapentane-1,5-diamine (H2L) has been prepared. Reaction of the shape-specific designed ligand with MnAc2 afforded a new complex, namely, [Mn2L2Ac2] 1. The ligand and complex 1 were characterized by physic-chemical and spectroscopic methods. The crystal structure of complex 1 has been determined by single-crystal X-ray diffraction. It reveals a centrosymmetric binuclear neutral entity, in which Mn(III) ion is bridged by two ligand L and six-coordinated with the coordination surround of distorted octahedron geometry. The antioxidant activities of the ligand and complex 1 were in vitro determined by superoxide and hydroxyl radical scavenging methods, which indicates that the complex 1 exhibits better scavenging activity of hydroxyl radical and superoxide radical than the ligand. Moreover, under the excitation at room temperature, luminescence studies have been carried out on solution-state samples. The result of their fluorescence properties shows that the strong and characteristic luminescence for the ligand and complex. The complex 1 exhibited intense shift in the fluorescence band compare to the ligand attributed to the coupled effect of the metal and the ligand.
Synthesis, crystal structure, antioxidation and fluorescence of two lanthanide complexes with a noncyclic polyether Schiff base ligand
Shi, Xinkui,Mao, Shanshan,Shen, Kesheng,Wu, Huilu,Tang, Xia
, p. 2015 - 2028 (2017)
Two lanthanide (Sm and La) complexes with the Schiff base ligand bis(3-methoxysalicylidene)-3-oxapentane-1,5-diamine (Bod) have been synthesized and characterized by physico-chemical and spectroscopic methods. [Sm(Bod)(NO3)3] {bis(3-methoxysalicylidene)-3-oxapentane-1,5-diamine samarium(III) trinitrate} (1) is a discrete mononuclear species and [La(Bod)(NO3)3(DMF)]n {bis(3-methoxysalicylidene)-3-oxapentane-1,5-diamine dimethylformamide lanthanum(III) trinitrate}n (2) formed an inorganic coordination polymer. In the two complexes, the metal ions are both ten-coordinate and the geometric structure around the Ln(III) ions can be described as distorted hexadecahedral. An antioxidant assay in vitro shows that complexes 1 and 2 exhibit better scavenging activity than both the ligand and the usual antioxidants on hydroxyl and superoxide radicals. Under excitation at room temperature, a red shift in the fluorescence band of the ligand in the complexes compared with that of the free ligand can be attributed to coordination of the rare earth ions to the ligand. Furthermore, 1 produced characteristic Sm(III) luminescence, which indicates the ligand Bod is a good organic chelator to absorb energy and transfer it to the Sm3+ ion.
A convenient preparation of diamino oligoethylene glycols and amino polyethylene glycols
Yinglin,Tianbao,Hongwen,Xiao
, p. 79 - 84 (1991)
Diamino oligoethylene glycols and amino polyethylene glycols were prepared in good yields by using the reaction of sodium diformamide with oligoethylene glycol or polyethylene glycol dichlorides or ditosylates followed by hydrolysis using ethanolic hydrochloride.
Synthesis and cytotoxic activity of novel 11-methyl-6H-pyrido[4,3-b]carbazole derivatives linked to amine, N-methylurea, and N-methyl-N-nitrosourea moieties with various types of carbamoyl tethers at the C-5 atom
Kato, Asako,Nagatsuka, Yusuke,Hiratsuka, Tomokazu,Kiuchi, Satoko,Iwase, Yoko,Okuno, Yuri,Tsukamoto, Tetsuya,Kiran,Sakai, Norio,Konakahara, Takeo
, p. 4258 - 4272 (2016)
Thirty-five types of novel pyridocarbazoles (5-(N-alkyl)carbamoyl-11-methyl-6H-pyrido[4,3-b]carbazoles and 5-(N-alkyl)carbamoyl-2,11-dimethyl-6H-pyrido[4,3-b]carbazol-2-ium chloride derivatives), that were conjugated with amine, N-methylurea, and N-methyl-N-nitrosourea moieties through alkyl-, oxyalkyl-, and iminoalkylcarbamoyl linkers, were synthesized by a series of reactions of methyl 11-methyl-6H-pyrido[4,3-b]carbazole-5-carboxylates with polymethylenediamine (n=2–5), p-nitrophenyl N-methylcarbamate, and N-methyl-N-nitrosocarbamate in high yields, and their cytotoxic activities were evaluated against Sarcoma-180, NIH3T3, HeLa S-3, and L1210?cell lines. These compounds exhibited potent cytotoxic activity (IC50=1.6–50?μM) and odd-even alternation effect. 9-Methoxy-2,11-dimethyl-5-((2-(3-methyl-3-nitrosoureido)ethyl)carbamoyl)-6H-pyrido[4,3-b]carbazol-2-ium chloride exhibited the most potent cytotoxic activity (IC50=0.15?μM) and cell selectivity against HeLa S-3. Some of the un-charged 5-(N-alkyl)carbamoyl-6H-pyrido[4,3-b]carbazole derivatives, which were conjugated with the amine and N-methyl-N-nitrosourea moieties through a dimethylene spacer, also exhibited potent cytotoxic activity (IC50=0.43–2.4?μM) and remarkable cell selectivity as well as ellipticine, 9-hydroxyellipticine, and the starting methyl ester of the pyridocarbazole-5-carboxylate (IC50=0.30–2.2?μM).
Lower ligand denticity leading to improved thermodynamic and kinetic stability of the Gd3+ complex: The strange case of OBETA
Baranyai, Zsolt,Botta, Mauro,Fekete, Marianna,Giovenzana, Giovanni B.,Negri, Roberto,Tei, Lorenzo,Platas-Iglesias, Carlos
, p. 7680 - 7685 (2012)
OBETA, OBETA, you bet: Thermodynamic and kinetic measurements show an apparent paradox. The stability of complexes of lanthanide trivalent ions is higher with the heptadentate ligand OBETA (ethylene glycol-bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic aci
Dicopper(II) Complexes of an N6O2 Macrocycle and Seven-co-ordinate Manganese(II), Iron(II), Cobalt(II), Nickel(II), Copper(II), and Zinc(II) Complexes of its N5O2 Open-chain Precursor
Nelson S. Martin,Knox C. Victor
, p. 2525 - 2528 (1983)
The syntheses via metall-ion (Mg(2+), Ca(2+), or Ba(2+)) template methods followed by transmetallation, of the complexes (ML1)X2 (M=MnII, FeII, CoII, NiII, CuII, or ZnII; X=ClO4(1-) or BPh4(1-)) of the potentially septidentate ligand L1 formed by condensation of 1 mol of 2,6-diacetylpyridine with 2 mol of 3-oxapentane-1,5-diamine is described.The collective evidence of the properties (magnetic and spectroscopic) of the complexes indicates a seven-co-ordinate (pentagonal-bipyramidal) structure.Ring closure, via a transamination mechanism, of L1 in BaL1(ClO4)2 leads to the complex BaL2(ClO4)2*3H2O containing the 24-membered N6O2 macrocyclic ligand L2.The single Ba(2+) in this complex may be replaced by two copper(II) ions to afford the binuclear complex Cu2L2(ClO4)4*H2O which on treatment with imidazole (Him) gives Cu2L2(im)(ClO4)3*H2O containing an imidazolate bridge between the antiferromagnetically coupled metal centres.
Chemical Promiscuity of Non-Macrocyclic Multidentate Chelating Ligands for Radiometal Ions: H4neunpa-NH2vs H4noneunpa
Wharton, Luke,Kurakina, Elena,Radchenko, Valery,Schaffer, Paul,Orvig, Chris
supporting information, p. 4076 - 4092 (2021/04/07)
A comparative investigation of two structurally related potentially nonadentate chelating ligands, H4neunpa-NH2 and H4noneunpa, has been undertaken to examine the influence of bifunctionalization on their coordination chemistry and metal ion selectivity. Significantly improved synthetic routes for each compound have been developed, employing straightforward high-yielding strategies. Radiolabeling studies with [44Sc]Sc3+, [111In]In3+, [177Lu]Lu3+, and [225Ac]Ac3+ revealed a sharp contrast between the affinity of each chelator for large radiometal ions. H4noneunpa demonstrated highly effective coordination of [177Lu]Lu3+ and [225Ac]Ac3+ achieving quantitative radiochemical yields (>98%) at ligand concentrations of 10-6 M (room temperature (RT), 10 min), with excellent stability when challenged in human serum, while H4neunpa-NH2 was unable to complex either metal ion effectively. Nuclear magnetic resonance (NMR) spectroscopy was employed to explore the coordination chemistry of each chelating ligand with nonradioactive metal ions, spanning a range of ionic radii and coordination numbers. A comprehensive conformational analysis of each metal complex was undertaken using density functional theory (DFT) calculations to explore the coordination geometries and explain the discrepancy in binding characteristics. Theoretical simulations revealed notable differences in the coordination geometry and apparent denticity of each ligand, which together account for the observed selectivity in metal binding and have important implications for the future design of complexes based upon this framework to target large radiometal ion coordination.
Electrochemical CO2 Reduction-The Effect of Chalcogenide Exchange in Ni-Isocyclam Complexes
Apfel, Ulf-Peter,Battistella, Beatrice,Gerschel, Philipp,Ray, Kallol,Siegmund, Daniel
, p. 1497 - 1510 (2020/04/30)
Among the numerous homogeneous electrochemical CO2 reduction catalysts, [Ni(cyclam)]2+ is known as one of the most potent catalysts. Likewise, [Ni(isocyclam)]2+ was reported to enable electrochemical CO2 conversion but has received significantly less attention. However, for both catalysts, a purposeful substitution of a single nitrogen donor group by chalcogen atoms was never reported. In this work, we report a series of isocyclam-based Ni complexes with {ON3}, {SN3}, {SeN3}, and {N4} moieties and investigated the influence of nitrogen/chalcogen substitution on electrochemical CO2 reduction. While [Ni(isocyclam)]2+ showed the highest selectivity toward CO2 reduction within this series with a Faradaic efficiency of 86% for the generation of CO at an overpotential of-1.20 V and acts as a homogeneous catalyst, the O-and S-containing Ni complexes revealed comparable catalytic activities at ca. 0.3 V milder overpotential but tend to form deposits on the electrode, acting as precursors for a heterogeneous catalysis. Moreover, the heterogeneous species generated from the O-and S-containing complexes enable a catalytic hydride transfer to acetonitrile, resulting in the generation of acetaldehyde. The incorporation of selenium, however, resulted in loss of CO2 reduction activity, mainly leading to hydrogen generation that is also catalyzed by a heterogeneous electrodeposit.
Bivalent HIV-1 fusion inhibitors based on peptidomimetics
Kobayakawa, Takuya,Ebihara, Kento,Tsuji, Kohei,Kawada, Takuma,Fujino, Masayuki,Honda, Yuzuna,Ohashi, Nami,Murakami, Tsutomu,Tamamura, Hirokazu
, (2020/11/07)
Membrane fusion is a valid target for inhibition of HIV-1 replication. A 34-mer fragment peptide (C34), which is contained in the HIV-1 envelope protein gp41, has significant anti-HIV activity. Previously, a dimeric derivative of C34 linked by a disulfide bridge at its C-terminus was found to have more potent anti-HIV activity than the C34 peptide monomer. To date, several peptidomimetic small inhibitors have been reported, but most have lower potency than peptide derivatives related to C34. In the present study we applied this dimerization concept to these peptidomimetic small inhibitors and designed several bivalent peptidomimetic HIV-1 fusion inhibitors. The importance of the length of linkers crosslinking two peptidomimetic compounds was demonstrated and several potent bivalent inhibitors containing tethered peptidomimetics were produced.
Synthesis method of 2'-oxydiethylamine and product thereof
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Page/Page column 6-9, (2019/08/12)
The invention discloses a synthesis method of 2'-oxydiethylamine and the product thereof, and belongs to the field of compound production. The method comprises the steps of using dichlorodiethyl etheras an initial raw material, then carrying out heating reaction on the dichlorodiethyl ether and phthalimide potassium in a first organic solvent at first to generate 2,2'-diphthalimide diethyl ether,carrying out heating reflux reaction on the 2,2'-diphthalimide diethyl ether and hydrazine hydrate in a second organic solvent after purifying the 2,2'-diphthalimide diethyl ether to generate a crudeproduct 2'-oxydiethylamine, and purifying the crude product 2'-oxydiethylamine to obtain the pure product 2'-oxydiethylamine. The product produced through the method is high in yield and high in purity, and the controllability is high; and the purity of the obtained product is greatly improved compared with that of a product obtained through a conventional method.
