82894-83-5Relevant academic research and scientific papers
Spin-labeling luotonin A compound as well as preparation method and application thereof
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Paragraph 0008; 0017; 0018, (2017/08/27)
The invention discloses a spin-labeling luotonin A compound of formula (I) as shown in the specification, as well as a preparation method and application of the compound. In-vitro antitumor activity screening results show that compared with luotonin A, the spin-labeling luotonin A compound disclosed by the invention is relatively intense in inhibition activity on human lung adenocarcinoma cells (A549), human breast cancer cell lines (MDA-MB-468), human ovarian neoplasm cells (SKOV3) and human colon cancer cell lines (HCT 116), and has good application prospects.
2′-Alkynylnucleotides: A Sequence- and Spin Label-Flexible Strategy for EPR Spectroscopy in DNA
Haugland, Marius M.,El-Sagheer, Afaf H.,Porter, Rachel J.,Pe?a, Javier,Brown, Tom,Anderson, Edward A.,Lovett, Janet E.
, p. 9069 - 9072 (2016/08/05)
Electron paramagnetic resonance (EPR) spectroscopy is a powerful method to elucidate molecular structure through the measurement of distances between conformationally well-defined spin labels. Here we report a sequence-flexible approach to the synthesis of double spin-labeled DNA duplexes, where 2′-alkynylnucleosides are incorporated at terminal and internal positions on complementary strands. Post-DNA synthesis copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions with a variety of spin labels enable the use of double electron-electron resonance experiments to measure a number of distances on the duplex, affording a high level of detailed structural information.
Approaches to the synthesis of a water-soluble carboxy nitroxide
Thomas, Komba,Chalmers, Benjamin A.,Fairfull-Smith, Kathryn E.,Bottle, Steven E.
, p. 853 - 857 (2013/03/29)
The robust and diversely useful isoindoline nitroxide, 5-carboxy-1,1,3,3- tetramethylisoindolin-2-yloxyl (1; CTMIO), has previously been synthesised in low-to-moderate yields from phthalic anhydride (3). Recent interest in its biological potential as a potent antioxidant and in other areas has seen an increased demand for its production. Herein, three new synthetic routes to CTMIO are presented and their efficiencies assessed. Two routes, via the nitrile 9 and the formyl compound 11, derive from 5-bromo-1,1,3,3-tetramethylisoindoline (6). The third approach starts from the readily accessible starting material, 4-methylphthalic anhydride (12), and proceeds by a methylarene oxidation with potassium permanganate. The three new approaches yield CTMIO in comparable overall yields (16-18 %); however, the synthetic efficiency is most improved when employing the nitrile intermediate 9. Copyright
Ligand-enhanced aliphatic carbon-carbon bond activation of nitroxides by rhodium(II) porphyrin
Chan, Kin Shing,Li, Xin Zhu,Lee, Siu Yin
scheme or table, p. 2850 - 2856 (2010/10/03)
Rh(tmp) underwent Ph3P-enhanced aliphatic carbon-carbon bond activation with various nitroxides. (Ph3P)Rh(tmp), rapidly formed from Rh(tmp) and Ph3P, enhanced the rate, selectivity, and yield in comparison to Rh(tmp). From kinetic studies, the rate of reaction showed a first-order dependence on both Rh(tmp) and TEMPO (TEMPO = 2,2,6,6- tetramethylpiperidine-1-oxyl) and saturation kinetics on Ph3P. The rate enhancement of (Ph3P)Rh(tmp) over Rh(tmp) was estimated to be about 11 at 70 °C.
Conformationally unambiguous spin labeling for distance measurements
Sajid, Muhammad,Jeschke, Gunnar,Wiebcke, Michael,Godt, Adelheid
supporting information; experimental part, p. 12960 - 12962 (2010/07/03)
An iDEER about molecular structure: Measurements of interspin distances through double electron-electron resonance (DEER) experiments allow information to be gained about the structure of molecules (see figure). The less variability in the orientation of the N-O axis of nitroxyl spin labels with respect to the labeled molecule, the smaller the distribution of the interspin distance and thus the better the conclusion.
Reactions of nitroxides with metalloporphyrin alkyls bearing beta hydrogens: Aliphatic carbon-carbon bond activation by metal centered radicals
Chan, Kin Shing,Mak, Kin Wah,Tse, Man Kin,Yeung, Siu Kwan,Li, Bao Zhu,Chan, Yun Wai
, p. 399 - 407 (2008/03/18)
Nitroxide-induced beta-hydrogen atom abstraction and beta-elimination of rhodium porphyrin alkyls have been observed. Rhodium(II) porphyrin radical were proposed intermediates to form first and subsequently reacted via aliphatic carbon-carbon bond activation with alkyl substituted nitroxides to yield rhodium porphyrin alkyl complexes.
Synthesis of 1,1,3,3-tetraalkylisoindolines using a microwave-assisted grignard reaction
Foitzik, Richard C.,Bottle, Steven E.,White, Jonathan M.,Scammells, Peter J.
, p. 168 - 171 (2008/09/18)
1,1,3,3-Tetraalkylisoindolines are important intermediates in the preparation of stable nitroxides, such as 1,1,3,3-tetramethylisoindolin-2-oxyl, 1, and 1,1,3,3-tetraethylisoindolin-2-oxyl, 2. The limiting step in their preparation is the Grignard reactio
ACE-INHIBITORS HAVING ANTIOXIDANT AND NO-DONOR ACTIVITY
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Page/Page column 63, (2010/02/07)
Multifonctional ACE inhibitor compounds are provided, that combine ACE-inhibiting activity with capability to scavenge superoxide and other reactive oxygen species, and that may further function as nitric oxide donors. The compounds are useful for preventing or treating various disorders, including cardiovascular, and diabetes associated disorders.
Nitroxyl radical reactions with 4-pentenyl- and cyclopropylketenes: New routes to 5-hexenyl- and cyclopropylmethyl radicals
Allen,Fenwick,Henry-Riyad,Tidwell
, p. 5759 - 5765 (2007/10/03)
4-Pentenylketenes 4a and 9 and cyclopropylketenes 3a, 13, 14 (RCH=C=O) are generated by photochemical Wolff rearrangements and observed by IR as relatively long-lived species at room temperature in hydrocarbon solvents. The reactions of these ketenes with the nitroxyl radicals tetramethylpiperidinyloxyl (TEMPO, TO?) and tetramethylisoindoline-2-oxyl (TMIO, IO?) form carboxy substituted 5-hexenyl and cyclopropylmethyl radicals which are either trapped by a second nitroxyl radical or undergo rearrangements followed by trapping. The rate constant of the reaction of 4a with TEMPO was similar to that of n-BuCH=C=O (1b), while 3a was 4.3 times more reactive, indicating cyclopropyl stabilization of the incipient radical.
Synthesis of the Radical Scavenger 1,1,3,3-Tetramethylisoindolin-2-yloxyl
Griffiths, Peter G.,Moad, Graeme,Rizzardo, Ezio,Solomon, David H.
, p. 397 - 401 (2007/10/02)
A versatile free-radical trapping agent, 1,1,3,3-tetramethylisoindolin-2-yloxyl, has been prepared from N-benzylphthalimide by reaction with 'methylmagnesium iodide' in refluxing toluene followed by hydrogenolysis and oxidation.The Grignard reaction gives 2-benzyl-1,1,3,3-tetramethylisoindoline along with a small proportion of an unexpected by-product, 2-benzyl-1-ethyl-1,3,3-trimethylisoindoline.
