21708-31-6Relevant academic research and scientific papers
Shear Stress-Responsive Polymersome Nanoreactors Inspired by the Marine Bioluminescence of Dinoflagellates
Rifaie-Graham, Omar,Galensowske, Nikolas F. B.,Dean, Charlie,Pollard, Jonas,Balog, Sandor,Gouveia, Micael G.,Chami, Mohamed,Vian, Antoine,Amstad, Esther,Lattuada, Marco,Bruns, Nico
, p. 904 - 909 (2021)
Some marine plankton called dinoflagellates emit light in response to the movement of surrounding water, resulting in a phenomenon called milky seas or sea sparkle. The underlying concept, a shear-stress induced permeabilisation of biocatalytic reaction compartments, is transferred to polymer-based nanoreactors. Amphiphilic block copolymers that carry nucleobases in their hydrophobic block are self-assembled into polymersomes. The membrane of the vesicles can be transiently switched between an impermeable and a semipermeable state by shear forces occurring in flow or during turbulent mixing of polymersome dispersions. Nucleobase pairs in the hydrophobic leaflet separate when mechanical force is applied, exposing their hydrogen bonding motifs and therefore making the membrane less hydrophobic and more permeable for water soluble compounds. This polarity switch is used to release payload of the polymersomes on demand, and to activate biocatalytic reactions in the interior of the polymersomes.
A heptamethine cyanine-based colorimetric and ratiometric fluorescent chemosensor for the selective detection of Ag+ in an aqueous medium
Zheng, Hong,Yan, Min,Fan, Xiao-Xing,Sun, Dan,Yang, Shi-Yao,Yang, Li-Jiao,Li, Jun-Dong,Jiang, Yun-Bao
, p. 2243 - 2245 (2012)
A highly selective and sensitive ratiometric fluorescent chemosensor for Ag+ in aqueous solution was developed, in a linear range of 0.6 × 10-7 to 50 × 10-7 mol L-1, based on a A-Ag+-A binding mode with a heptamethine cyanine motif containing one adenine moiety.
FORCE-RESPONSIVE POLYMERSOMES AND NANOREACTORS; PROCESSES UTILIZING THE SAME
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Paragraph 0102, (2019/03/05)
The mechanically induced melting properties of DNA were employed to achieve force labile membranes is described. Nucleobase pairs were used as mechanophores. Adenine and thymine functionalized complementary amphiphilic block copolymers were self-assembled
Peptidyl α-ketoamides with nucleobases, methylpiperazine, and dimethylaminoalkyl substituents as calpain inhibitors
Ovat, Asli,Li, Zhao Zhao,Hampton, Christina Y.,Asress, Seneshaw A.,Fernández, Facundo M.,Glass, Jonathan D.,Powers, James C.
supporting information; experimental part, p. 6326 - 6336 (2010/10/20)
A series of peptidyl α-ketoamides with the general structure Cbz-l-Leu-d,l-AA-CONH-R were synthesized and evaluated as inhibitors for the cysteine proteases calpain I, calpain II, and cathepsin B. Nucleobases, methylpiperazine, and dimethylaminoalkyl groups were incorporated into the primed region of the inhibitors to generate compounds that potentially cross the blood-brain barrier. Two of these compounds (Cbz-Leu-d,l-Abu-CONH-(CH 2)3-adenin-9-yl and Cbz-Leu-d,l-Abu-CONH-(CH 2)3-(4-methylpiperazin-1-yl) have been shown to have useful concentrations in the brain in animals. The best inhibitor for calpain I was Cbz-Leu-d,l-Abu-CONH-(CH2)3-2-methoxyadenin-9-yl (Ki = 23 nM), and the best inhibitor for calpain II was Cbz-Leu-d,l-Phe-CONH-(CH2)3-adenin-9-yl (Ki = 68 nM). On the basis of the crystal structure obtained with heterocyclic peptidyl α-ketoamides, we have improved inhibitor potency by introducing a small hydrophobic group on the adenine ring. These inhibitors have good potential to be used in the treatment of neurodegenerative diseases.
Cocrystal structures of primed side-extending α-ketoamide inhibitors reveal novel calpain-inhibitor aromatic interactions
Qian, Jin,Cuerrier, Dominic,Davies, Peter L.,Li, Zhaozhao,Powers, James C.,Campbell, Robert L.
experimental part, p. 5264 - 5270 (2009/07/09)
Calpains are intracellular cysteine proteases that catalyze the cleavage of target proteins in response to Ca2+ signaling. When Ca2+ homeostasis is disrupted, calpain overactivation causes unregulated proteolysis, which can contribute to diseases such as postischemic injury and cataract formation. Potent calpain inhibitors exist, but of these many cross-react with other cysteine proteases and will need modification to specifically target calpain. Here, we present crystal structures of rat calpain 1 protease core (μI-II) bound to two α-ketoamide-based calpain inhibitors containing adenyl and piperazyl primed-side extensions. An unexpected aromatic-stacking interaction is observed between the primed-side adenine moiety and the Trp298 side chain. This interaction increased the potency of the inhibitor toward μI-II and heterodimeric m-calpain. Moreover, stacking orients the adenine such that it can be used as a scaffold for designing novel primed-side address regions, which could be incorporated into future inhibitors to enhance their calpain specificity.
Syntheses and coordination chemistry of aminomethylphosphine derivatives of adenine
Zhang, Qingzhi,Hua, Guoxiong,Bhattacharyya, Pravat,Slawin, Alexandra M. Z.,Woollins, J. Derek
, p. 2426 - 2437 (2007/10/03)
Two aminomethylphosphane derivatives of adenine 9-(2-{bis[(diphenylphosphanyl)methyl]amino}ethyl)adenine (La) and 9-(3-{bis[(diphenylphosphanyl)methyl]amino}propyl)adenine (Lb) were synthesised. Oxidation of La and Lb with H2O2, elemental sulfur or elemental selenium led to the corresponding oxidized products 4a/b-6a/b. Both La and Lb behave as didentate ligands towards late transition metals. Reaction of La or Lb with [MX2(cod)] (M = Pd, Pt; X = Cl, Me) gave chelate complexes 7a/b-10a/b. Reaction of La or Lb with [AuCl(tht)] of [{RuCl(μ-Cl)(p-MeC6H4iPr)}2] gave the didentate bridging complexes 11a/b and 12a. All compounds have been fully characterised by microanalysis, IR, 1H and 31P{1H} NMR spectroscopy, and EI/CI/FAB mass spectrometry. 1H{31P} NMR and 1H-13C correlation experiments were used to confirm the spectral assignments where necessary. Two compounds were structurally characterised by X-ray crystallographic analysis. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
