摘要:
An object of a first aspect of the present invention is to provide a radical generating catalyst that can generate (produce) radicals under mild conditions. In order to achieve the above object, a first radical generating catalyst according to the first aspect of the present invention is characterized in that it includes ammonium and/or a salt thereof. A second radical generating catalyst according to the first aspect of the present invention is characterized in that it includes an organic compound having Lewis acidic properties and/or Brønsted acidic properties.
摘要:
The invention relates to a solution containing a nitroxide radical for magnetometry by nuclear magnetic resonance. This solution is constituted by a nitroxide radical of formula: ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which can be the same or different, represent an alkyl group or an alkoxy group which may be deuterated, or in which the pairs R.sup.1 -R.sup.2 and/or R.sup.3 -R.sup.4 together form an optionally deuterated cycloalkyl or polycycloalkyl group, and N represent .sup.14 N or .sup.15 N, dissolved in a solvent having an oxidizing power and an appropriate viscosity. The solvent can be constituted by a mixture of water and two compounds respectively playing the part of the oxidizing agent and viscosity modifying agent, e.g. water, ethylene glycol and NalO.sub.4, or can be solely constituted by a mixture of water and an oxidizing agent able to modify the viscosity, such as acetic acid.
摘要:
An object of a first aspect of the present invention is to provide a radical generating catalyst that can generate (produce) radicals under mild conditions. In order to achieve the above object, a first radical generating catalyst according to the first aspect of the present invention is characterized in that it includes ammonium and/or a salt thereof. A second radical generating catalyst according to the first aspect of the present invention is characterized in that it includes an organic compound having Lewis acidic properties and/or Brønsted acidic properties.
摘要:
The invention provides novel persistent free radicals useful in Overhauser MRI being triarylmethyl radicals having as at least one aryl group a group of formula ##STR1## (wherein each X which may be the same or different is an oxygen or sulphur atom or a group CO or S(O).sub.n, (where n is 1 to 3) with the proviso that at least one group X is a sulphur atom or a S(O).sub.n group; R.sup.1 is a hydrogen atom or group of formula --M, --XM, --X--Ar.sup.2, or --Ar.sup.2 where M is a water solubilizing group, and Ar.sup.2 represents a 5-10 membered aromatic ring optionally substituted by a water solubilizing group M; and each of the groups R.sup.7, which may be the same or different, is a hydrogen atom, or a hydrocarbon group or a water solubilizing group M, or two groups R.sup.7 together with the atom to which they are bound represent a carbonyl group or a 5 to 8 membered cycloalkylidene, mono- or di-oxacycloalkylidene, mono- or di-azacycloalkylidene or mono- or di-thiacycloalkylidene group optionally with the ring attachment carbon replaced by a silicon atom, and R.sup.7 where it is other than hydrogen, is optionally substituted by a hydroxyl group, an optionally alkoxylated, optionally hydroxylated acyloxy or alkyl group or a water solubilizing group M)). The novel radicals have good stability, long relaxation times and good relaxivity.
摘要:
Selective isotopic-labeling of spin label compounds, used in electron spin resonance spectroscopy to detect, measure and monitor the presence of paramagnetic species, increases the sensitivity of the electron spin resonance technique in assays for paramagnetic species, such as the determination of oxygen tension in solution or in a biological sample, like a living organism. Spin label compounds, such as nitroxides, like 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrroline-1-yloxyl (CTPO), are selectively, but not completely, isotopically-labeled, such as partially deuterated, to increase the sensitivity and reliability of assays employing electron spin resonance spectroscopic measurements.
摘要:
The invention relates to a process for the preparation of secondary nitroxide radicals from their corresponding secondary amines by oxidation with an organic peracid, comprising the steps a) adding to a reaction vessel a secondary amine, optionally together with an organic solvent and in one batch a base selected from the group consisting of alkali metal, alkaline earth metal or ammonium bicarbonates and alkaline earth metal or ammonium carbonates or mixtures thereof in the form of a solid together with water or as an aqueous slurry; b) dosing a peracid under stirring to the reaction mixture in an amount of 1.0 to 2.5 mol per mol of secondary amine; and c) isolating the organic phase.
摘要:
The invention concerns a method for preparing &bgr;-phosphorous nitroxide radicals which comprises preparing in a first step an aminophosphonate by reacting a carbonyl compound, a primary amine and a phosphorous compound, then in a second step in oxidizing said aminophosphonate using on-halogenated organic peracids in a two-phase organic water/solvent medium with a buffered aqueous phase with a pH ranging between 5 and 12.
摘要:
Procedure for the preparation of nitroxyl radicals of sterically hindered amines, consisting of the reaction of amines with hydrogen peroxide in the presence of a titanium containing catalyst, particularly in the presence of titanium silicalites.The catalyst can be recovered at the end of the reaction and recycled.
摘要:
The present invention provides a solid-phase support for oligonucleotide synthesis for synthesizing long chain oligonucleotide, RNA oligonucleotide and modified oligonucleotide at high synthetic quantity and high purity with a low loading amount of a linker. Provided is a solid-phase support for oligonucleotide synthesis comprising a porous resin bead having a monovinyl monomer unit, a crosslinkable vinyl monomer unit and a polyethylene glycol unit and a cleavable linker loaded on its surface, the porous resin bead having a group capable of binding to a carboxy group by a dehydration condensation reaction on its surface, the cleavable linker having a carboxy group, wherein the carboxy group of the cleavable linker is bound to the group capable of binding to a carboxy group, by a dehydration condensation reaction, and a loading amount of the cleavable linker is 1 to 80 μmol/g relative to the weight of the porous resin bead.
摘要:
Novel triarylmethyl free radicals, their use as image enhancing agents in MRI, in particular to their use in Overhauser enhanced MRI of a sample for determining oxygen concentration of said sample.