232923-90-9Relevant academic research and scientific papers
Porous Polyrotaxane Coordination Networks Containing Two Distinct Conformers of a Discontinuously Flexible Ligand
Hawes, Chris S.,Knowles, Gregory P.,Chaffee, Alan L.,White, Keith F.,Abrahams, Brendan F.,Batten, Stuart R.,Turner, David R.
, p. 10467 - 10474 (2016)
A new divergent homopiperazine-derived ligand N,N′-bis(4-carboxyphenyl)-1,4-diazacycloheptane H2L has been prepared, containing a semirigid saturated heterocyclic core which is capable of providing multiple distinct bridging geometries. Reaction of H2L with zinc acetate in DMSO gives a two-dimensional parallel interpenetrated polyrotaxane structure 1 in which the loops and rods are formed by the bent cis-(eq,ax) twist boat and trans-(ax,ax) twist chair conformers, respectively. By matching the distances between the solvated metal sites in the structure of 1, a related material 2 can be prepared incorporating the pillaring ligand trans-1,2-bis(4-pyridyl)ethylene bpe. Compound 2 displays a similar polyrotaxane interpenetration mode, permitted by the presence of both cis and trans ligand conformers, but displays a three-dimensional 2.69 topology related to the dia diamondoid network. The guest exchange and gas adsorption properties of both materials were investigated; while compound 1 displays poor stability to guest exchange and negligible gas uptake, the higher connectivity microporous compound 2 shows facile guest exchange and a surprisingly high CO2 capacity of 12 wt % at 1 bar and 273 K, and a zero-loading enthalpy of adsorption of -32 kJ mol-1. High-pressure adsorption isotherms also show moderate physisorption of H2 and CH4 within the material.
Antitumor and anti-Pneumocystis carinii activities of novel bisbenzamidines
Vanden Eynde, Jean Jacques,Mayence, Annie,Johnson, Melissa T.,Huang, Tien L.,Collins, Margaret S.,Rebholz, Sandra,Walzer, Peter D.,Cushion, Melanie T.,Donkor, Isaac O.
, p. 143 - 157 (2007/10/03)
Among a library of 17 bisbenzamidines connected with various linkers, compounds with a flexible pentanediamide (10) or hexanediamide (12) linker were the most potent derivatives against rat Pneumocystis carinii (IC50 values of 3 and 2 nM, respe
Trypanocidal activity of conformationally restricted pentamidine congeners
Donkor, Isaac O.,Huang, Tien L.,Tao, Bin,Rattendi, Donna,Lane, Schennella,Vargas, Marc,Goldberg, Burt,Bacchi, Cyrus
, p. 1041 - 1048 (2007/10/03)
A series of conformationally restricted congeners of pentamidine in which the flexible pentyl bridge of pentamidine was replaced by trans-1,2-bismethylenecyclopropyl, phenyl, pyridinyl, piperazinyl, homopiperazinyl, and piperidinyl groups were synthesized
Synthesis and anti-Pneumocystis carinii activity of conformationally restricted analogues of pentamidine
Tao, Bin,Huang, Tien L,Zhang, Qian,Jackson, Latasha,Queener, Sherry F.,Donkor, Isaac O.
, p. 531 - 538 (2007/10/03)
A series of conformationally restricted analogues of pentamidine in which the flexible central bridge has been replaced by trans-cyclopropyl, phenyl, pyridinyl, piperazinyl or homopiperazinyl groups as conformationally restricted linkers have been synthesized. The anti-Pneumocystis carinii activity of these compounds was evaluated in a cell culture model and the DNA binding affinity was determined by thermal denaturation measurements. At 1 μM, compounds 2, 3, 5, 7, 9 and pentamidine were highly effective and caused total inhibition of P. carinii growth in culture. At 0.1 μM, compounds 2, 5, 7 and 10 were more active than pentamidine with N, N'- bis(4amidinophenyl)piperazine 7 being approximately 15-fold more effective than pentamidine. The most active compounds, 7 and 10, showed strong binding affinities for calf thymus DNA and poly(dA-dT); however, a clear correlation between DNA binding affinity and the in vitro anti-P, carinii activity of these compounds was not observed. The results suggest that the nature of the central linker influences the biological actions of these compounds.
