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provides coniferyl ferulate(CAS#:294-90-6) MSDS, density, melting point, boiling point, structure, formula, molecular weight etc. Articles of coniferyl ferulate are included as well.>> amp version: coniferyl ferulate
Three 1,4,7,10-tetraazacyclododecane-based ligands disubstituted in 1,4-positions with phosphonic acid, phosphonate monoethyl-ester, and H-phosphinic acid pendant arms, 1,4-H4do2p, 1,4-H2do2pOEt, and 1,4-H2Bn2do2pH, were synthesized and their coordination to selected metal ions, Mg(II), Ca(II), Mn(II), Zn(II), Cu(II), Eu(III), Gd(III), and Tb(III), was investigated. The solid-state structure of the phosphonate ligand, 1,4-H4do2p, was determined by single-crystal X-ray diffraction. Protonation constants of the ligands and stability constants of their complexes were obtained by potentiometry, and their values are comparable to those of previously studied analogous 1,7-disubstitued cyclen derivatives. The Gd(III) complex of 1,4-H4do2p is ~1 order of magnitude more stable than the Gd(III) complex of the 1,7-analogue, probably due to the disubstituted ethylenediamine-like structural motif in 1,4-H4do2p enabling more efficient wrapping of the metal ion. Stability of Gd(III)-1,4-H2do2pOEt and Gd(III)-H2Bn2do2pH complexes is low and the constants cannot be determined due to precipitation of the metal hydroxide. Protonations of the Cu(II), Zn(II), and Gd(III) complexes probably takes place on the coordinated phosphonate groups. Complexes of Mn(II) and alkali-earth metal ions are significantly less stable and are not formed in acidic solutions. Potential presence of water molecule(s) in the coordination spheres of the Mn(II) and Ln(III) complexes was studied by variable-temperature NMR experiments. The Mn(II) complexes of the ligands are not hydrated. The Gd(III)-1,4-H4do2p complex undergoes hydration equilibrium between mono- and bis-hydrated species. Presence of two-species equilibrium was confirmed by UV-Vis spectroscopy of the Eu(III)-1,4-H4do2p complex and hydration states were also determined by luminescence measurements of the Eu(III)/Tb(III)-1,4-H4do2p complexes.
MRI contrast agents; copper; cyclen derivatives; gadolinium; macrocyclic ligands; manganese; metal complexes; phosphinate ligands; phosphonate ligands; protonation constants; stability constants.
Coordination Behavior of 1,4-Disubstituted Cyclen Endowed With Phosphonate, Phosphonate Monoethylester, and H-Phosphinate Pendant Arms
Jiři Barta 1, Petr Hermann 2, Jan Kotek 3
2019 Sep 12
Hydrogen sulfide (H2S) has been reported as a gaseous signaling molecule in cells. H2S modulation is dependent on the partial pressure of oxygen in cells, which means hypoxia can induce H2S production under various pathophysiological conditions. Hypoxia is a common condition in solid tumors and can lead to malignant tumors that may become aggressive and result in worse prognosis. We designed and synthesized probe Cu-CD for H2S detection under hypoxia conditions. It is selective and sensitive toward various biological thiols, reactive nitrogen species (RNS), and reactive oxygen species (ROS). The fluorescence intensity of Cu-CD in the cytoplasms of HeLa and EMT6 cells was enhanced in proportion to the concentration of exogenous/endogenous H2S. Moreover, Cu-CD can be able to detect endogenous H2S production accompanied by expression of HIF-1α. Therefore, Cu-CD can be a key tool to explore how H2S contributes to neovascularization and growth of solid tumor tissues in pathophysiological or hypoxic conditions.
Development of Dansyl Based Copper(ii) Complex to Detect Hydrogen Sulfide in Hypoxia
Jee Young Kim 1, Swarbhanu Sarkar, Kondapa Naidu Bobba, Phuong Tu Huynh, Abhinav Bhise, Jeongsoo Yoo
2019 Jul 24
1,4,7,10-Tetraazacyclododecane (cyclen) has a unique cyclic structure that endows it with a number of characteristics, including its cationic nature, easy modification and strong coordination ability toward a wide range of cations. Zn2+, which can easily coordinate to cyclen, is an essential metal ion for DNA binding. In this report, Zn(ii)-polycations derived from cyclen were studied as non-viral gene delivery vectors. Polycations were synthesized from diglycidyl ethers and cyclen through ring-opening polymerization, and then Zn(ii)-complexes were obtained by reacting the polycations with Zn(NO3)2·6H2O. UV absorption and circular dichroism spectra revealed that the Zn(ii)-complexes may induce apparent conformational changes of DNA, while polycations could not. Agarose gel retardation assay demonstrated that although the Zn(ii)-polycations exhibited slightly lower DNA binding ability compared to their polycation counterparts, they showed better DNA release, which might favor the gene transfection process. In vitro transfection results revealed that the coordination of Zn(ii) may dramatically increase the transfection efficiency of the polymers. In addition, almost all polycations and their Zn(ii)-complexes exhibited better serum tolerance than polyethylenimine (PEI), especially Zn-cyclen-HD. Flow cytometry and BSA adsorption experiments also demonstrated the good serum tolerance of the Zn(ii)-polycations. Meanwhile, such materials also exhibited acceptable cytotoxicities at transfection dosages. These results may afford us clues for developing novel non-viral gene vectors with high efficiency and biocompatibility.
Zn(ii) Coordination to Cyclen-Based Polycations for Enhanced Gene Delivery
Qing-Ying Yu 1, Yu Guo, Ji Zhang, Zheng Huang, Xiao-Qi Yu
2019 Jan 21