32889-11-5

Upstream product

• 578-66-5 8-amino quinoline 
• 79-04-9 chloroacetyl chloride 
• 607-35-2 8-nitroquinoline 

Downstream Products

• 1016513-92-0 C₁₇H₁₅N₃O₂ 
• 1314901-82-0 C₁₇H₁₅N₃O₂ 

Relevant academic research and scientific papers

Ligand-free copper-catalyzed regio- And stereoselective 1,1-alkylmonofluoroalkylation of terminal alkynes

The copper-catalyzed highly regio- and stereoselective 1,1-alkylmonofluoroalkylation of terminal alkynes with α-chloroacetamides and dialkyl 2-fluoromalonate or 2-fluoro-N,N-dialkyl-3-oxobutanamide without an external ligand has been realized. With this novel methodology, (E)-β-monofluoroalkyl-β,γ-unsaturated amides containing quaternary C-F centers can be easily constructed in good to excellent yields. This journal is

A water soluble FRET-based ratiometric chemosensor for Hg(ii) and S 2- applicable in living cell staining

A new highly sensitive and selective Hg(ii) probe, 2-(rhodamine-b- hydrazido)-N-(quinolin-8-yl)acetamide (L1) was developed and characterized. L1 specifically binds to Hg(ii) in the presence of a large excess of other competing ions with visually observable changes in both electronic and fluorescence spectral behaviour to make possible the naked eye detection of Hg(ii) at a very low level (up to 4.5 × 10-7 M) through a fluorescence resonance energy transfer (FRET) process in HEPES buffer (1 mM, pH 7.4; 2% EtOH) at 25 °C. The theoretical and experimental kinetic study also support the binding of Hg(ii) ion to induce the opening of the spirolactam ring in L1 for enabling the FRET process. Further studies reveal that the selective dissociation of the L-Hg complex in the presence of sulphide anions to restore the native structure of L1 is also useful in the detection of sulfide anions with a detection limit of a submicromolar range in the same medium of HEPES buffer (1 mM, pH 7.4; 2% EtOH) at 25 °C. L1 could be employed as a FRET based time dependent reversible chemosensor for imaging Hg(ii) in living cells and whole bodies, and also could be used as an imaging probe for the detection of sulfide anions in HeLa cells. This journal is the Partner Organisations 2014.

A light activated CMP conjugated 8-aminoquinoline turn-on fluorescent optode for selective determination of Th4+ in an aqueous environment

A new dibutyl(2-oxo-2-(quinolin-8-ylamino)ethyl)phosphinate (L) was designed, synthesised and developed as a light activated optode for Th4+ determination. The sensing performance of L was studied in solution and in the polymeric membrane phase using absorbance and emission techniques. The neutral ion carrier L exhibits weak fluorescence at 400 nm in CH3CN : H2O (9 : 1, v/v). Upon complexation of L with Th4+, the emission intensity at 486 nm was increased 100-fold due to chelation induced enhanced fluorescence. The L-Th4+ binding interaction was studied using both Hill's and Job's plots. They indicate the formation of complex species in a 2 : 1 ratio with an estimated binding constant of 2.66 × 104 M-2. Complex formation between L and Th4+ was studied by NMR (1H, 31P), FTIR and LC-MS analyses. In order to synthesize a probe for the sensing of Th4+ in 100% aqueous medium, the optode was prepared by immobilizing L as a neutral ion carrier in a PVC support using dioctyl phthalate (DOP) as a membrane solvent. The best performance of the optode was observed with a membrane composition of PVC : L : NaTPB : DOP in proportions of 35 : 5 : 3 : 57 (%, w/w) in the pH range of 4.0-8.0. The optode can detect Th4+ concentrations down to 1.1 nM with a fast response time of 15 s and the optical response remains unaltered even after 3 months; the optode sensor can be regenerated using Na2EDTA solution. Finally, the optode was used for the quantification of Th4+ in various water samples, monazite sand, and gas mantle samples.

Manganese(II) complexes of quinoline derivatives: Characterization, catalase activity, interaction with mitochondria and anticancer activity

In order to find mitochondria-targeted mimics of catalase that can attenuate the metabolism of oxygen for cancer chemotherapy, two complexes [Mn(QA)Cl2] and [Mn(QA)(OAc)(H2O)2](OAc) (QA = 2-di(picolyl)amine-N-(quinoline-8-yl)acetamide) were synthesized and characterized by spectroscopic methods. In addition, the crystal structure of [Mn(QA)Cl2] shows that the Mn(II) atom is coordinated by three N atoms (N1, N2,and N3), and one oxygen atom (O1) of the ligand QA, plus two chloride atoms (Cl1 and Cl2), forming a distorted octahedral geometry. The complex [Mn(QA)(OAc)(H2O)2](OAc) could disproportionate H2O2 in Tris-HCl solution at 37 °C, with K cat/K M = 9,226. Furthermore, both Mn(II) complexes were found to be active against the proliferation of HepG-2 cells and could attenuate the swelling of calcium-overloaded mitochondria. These results demonstrate that Mn(II) complexes of quinoline derivatives have potential as attenuators of the absorption of Ca2+ in mitochondria and can interfere with the metabolism of O2 for cancer chemotherapy.

A highly sensitive and selective ratiometric fluorescent sensor for Zn 2+ ion based on ICT and FRET

A ratiometric sensor (QA) for detecting Zn2+ with high sensitivity and selectivity was reported. The fluorescence changes of sensor upon the addition of Zn2+ were attributed to the conjugation of internal charge transfer and fluorescence resonance energy transfer mechanisms. There is a good linear relationship between the fluorescence ratio I 497nm/I420nm and the concentrations of Zn2+ ranging from 0 μM to 40 μM, which makes an effective ratiometric detection of Zn2+ ion. The limit of detection (LOD) was evaluated to be 33.6 nM. The imaging experiments indicated that QA is cell-permeable and can be used to detect Zn2+ within living cells with good selectivity over Cd2+.

The nature of binding of quinolate complex on the surface of ZnS quantum dots

We report that the Z-type binding rather than X-type binding was favored when 8-hydroxyquinoline (HQ) reacted with presynthesized ZnS quantum dots (Qdots) to form surface zinc quinolinate complexes having a preferred stoichiometry of 1:2 (surface Zn2+:HQ). Importantly, the higher solubility in polar solvents and high desorption coefficient (following Langmuir binding isotherm) of HQ-treated ZnS Qdot in DMSO solvent compared with those in methanol clearly indicated the favorable Z-type binding of HQ and thus the formation of surface octahedral ZnQ2 complex. Furthermore, the characteristics peaks in the 1H-nuclear magnetic resonance (NMR) spectrum of the desorbed species and the ligand density calculation of the surface complex (formed due to the reaction between HQ and ZnS Qdot) supported the octahedral ZnQ2 complex formation. Interestingly, the presence of dangling sulphide and the loss of planarity of ZnQ2 complex on the surface of ZnS Qdots (in turn gaining structural rigidity) may be the reasons for the Z-type binding of HQ. The specific binding might be the reason for superior optical properties and thermal stability of the surface ZnQ2 complex compared to the free ZnQ2 complex as such. The results can be considered important towards understanding the coordination chemistry of inorganic complex on the surface of Qdots and thus for their application potential.

New fluorogenic chemosensors derived from benzimidazole

[Figure not available: see fulltext.] We report the synthesis of new 1-substituted N-(anthracen-9-ylmethyl)-1H-benzimidazol-2-amines and 1,2,3-trisubstituted 1H-benzimidazolium chlorides containing anthracene fluorophores. Benzimidazol-2-amine derivatives

Dual-Modal Magnetic Resonance/Fluorescent Zinc Probes for Pancreatic β-Cell Mass Imaging

Despite the contribution of changes in pancreatic β-cell mass to the development of all forms of diabetes mellitus, few robust approaches currently exist to monitor these changes prospectively in vivo. Although magnetic-resonance imaging (MRI) provides a potentially useful technique, targeting MRI-active probes to the β cell has proved challenging. Zinc ions are highly concentrated in the secretory granule, but they are relatively less abundant in the exocrine pancreas and in other tissues. We have therefore developed functional dual-modal probes based on transition-metal chelates capable of binding zinc. The first of these, Gd·1, binds ZnII directly by means of an amidoquinoline moiety (AQA), thus causing a large ratiometric Stokes shift in the fluorescence from λem=410 to 500 nm with an increase in relaxivity from r1=4.2 up to 4.9 mM-1s-1. The probe is efficiently accumulated into secretory granules in β-cell-derived lines and isolated islets, but more poorly by non-endocrine cells, and leads to a reduction in T1 in human islets. In vivo murine studies of Gd·1 have shown accumulation of the probe in the pancreas with increased signal intensity over 140 minutes.

1,3-Di-amidoquinoline conjugate of calix[4]arene (L) as a ratiometric and colorimetric sensor for Zn2+: Spectroscopy, microscopy and computational studies

Carboxamidoquinoline appended calix[4]arene-1,3-di-conjugate (L) has been synthesized and characterized and its single crystal XRD structure has been established. L has been shown to act as selective ratiometric turn-on fluorescence sensor for Zn2+ up to a lowest concentration of 183 ± 18 ppb (2.82 μM) with a nine-fold enhancement by exhibiting blue-green emission. The coordination features of the species of recognition have been computationally evaluated by DFT methods and found to have distorted tetrahedral Zn2+ center in an N4 core. The spherical nano-structural features observed for L in TEM are being transformed into the Koosh nano-flower like structure when complexed with Zn2+ and hence these two can be easily differentiated. Even the features observed in AFM can distinctly differentiate L from its Zn2+ complex.

A selective and sensitive fluorescence probe for imaging endogenous zinc in living cells

A carboxamidoquinoline-based fluorescent Zn2+ probe 1 containing N/S/S heteroatoms as a receptor was designed and readily synthesized, which was featured by the Zn2+-induced red-shift of emission (45 nm) based on internal charge transfer (ICT) in an aqueous HEPES buffer (pH=7.4). Moreover, spectroscopic studies indicated that the composition of the complex 1-Zn 2+ was 1:1, which was also confirmed by X-ray crystallography. In addition, 1H NMR titration experiment suggested that probe 1 transformed from the amide tautomer to imidic acid tautomer after binding with Zn2+. The binding of zinc with 1 was easily reversed by addition of N,N,N′,N′-tetrakis(2-picolyl)ethylenediamine (TPEN) or EDTA. Furthermore, probe 1 was successfully applied to image both exogenous and endogenous zinc in living HeLa cells.