- The bisnaphthalimides as new active lead compounds against Plasmodium falciparum
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The bisquaternary bisnaphthalimides are a versatile class of compounds being active against the malaria parasite Plasmodium falciparum in the lower nanomolar range of concentration combined with no cytotoxicity. The series of compounds is designed as choline analogues and interfering agents of the phosphatidylcholine biosynthesis. The qualitative analysis of the structure-activity relationships (SAR) revealed the importance of a long methylene middle chain of at least 8 methylene groups between the two bisquaternary naphthalimides or a monoquaternary naphthalimide consisting of a long alkyl chain attached to the positively charged nitrogen atom. Since the SARs are different from reported biscationic antimalarial drugs the mode of action remains to be elucidated.
- Tischer, Maximilian,Sologub, Ludmilla,Pradel, Gabriele,Holzgrabe, Ulrike
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- Self-aggregation of synthesized novel bolaforms and their mixtures with sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) in aqueous medium
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Bolaforms B1, B2, and B3 of the formulas, Br-Me3N+(CH2)10N +Me3Br-, Br-Me3N +(CH2)10OH, and Br-Me 3N+(CH2)10COO-Na +, respectively, were synthesized, and their properties in the bulk as well as at the air/aqueous NaBr (10 mM) solution interface have been studied. Their interactions with sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) also have been investigated. Tensiometry, conductometry, spectrophotometry, and microcalorimetry techniques were used for characterization and estimation. Both pure bolaforms and their mixtures with SDS and CTAB have been found to self-aggregate, forming micelles in solution. The mixed systems of bolaform and SDS have been observed to form both micelles and vesicles. Their mutual interactions were synergistic, which at the interface was more spontaneous than in the bulk. The interfacial and bulk compositions of the mixed binary systems (bolaform and SDS or CTAB) with their associated interaction parameters have been estimated from the Rosen interaction model and the regular solution theory of Rubingh, respectively. The formed vesicles have been found to entrap the water-soluble dye, bromophenol blue, and the dye solubilized vesicles of B1-SDS and B2-SDS completely eluted out of the sephadex column proving their formation. A rough estimation of the size and polydispersity index of the formed micelles and vesicles has been made from DLS measurements.
- Maiti, Kajari,Mitra, Debolina,Mitra, Rajendra N.,Panda, Amiya K.,Das, Prasanta K.,Rakshit, Animesh K.,Moulik, Satya P.
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experimental part
p. 7499 - 7508
(2010/11/04)
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- Orientational isomers of α-cyclodextrin [2]semi-rotaxanes with asymmetric dicationic threads
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Two series of novel dicationic threading molecules [Quin(CH 2)10R]2+ and [3,5-Lut(CH2) 10R]2+, where Quin- = quinuclidinium. 3,5-Lut+ = 3,5-lutidinium, and R+ = N(CH3) 3+ and N(CH3)2CH2CH 3+, form [2]semi-rotaxanes with α-cyclodextrin (α-CD) in aqueous solution. The quinuclidinium and 3.5-lutidinium arc sufficiently bulky to prevent threading while the R+ groups allow for slow threading by α-CD at 25°C. The resulting [2]semi-rotaxanes exist in two orientational isomers owing to the asymmetry of both the α-CD cavity and the threading molecules. Two-dimensional 1H NMR spectroscopy and kinetics experiments reveal that the isomer in which the narrower rim (primary OHs) is positioned near the R+ group is the kinetically preferred isomer, while the other isomer is the thermodynamically preferred product. The kinetics and mechanism of the formation, dissociation, and interconversion of the two isomers have been determined at 25°C. The Royal Society of Chemistry 2005.
- Baer, Andrew J.,Macartney, Donal H.
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p. 1448 - 1453
(2007/10/03)
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- Kinetics of the self-assembly of α-cyclodextrin [2]pseudorotaxanes with polymethylene threads bearing quaternary ammonium and phosphonium end groups
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The kinetics and mechanism of the formation and dissociation of a series of [2]pseudorotaxanes, comprised of α-cyclodextrin (α-CD) as the cyclic component and the ([Me3N(CH2)(n)NMe3]2+ (n = 8-12), [Me2/sub
- Lyon, Angela P.,Banton, Nicola J.,Macartney, Donal H.
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p. 843 - 850
(2007/10/03)
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