Planar Bilayer Conductance and Fluorescence Studies Confirm the Function and Location of a Synthetic, Sodium-Ion-Conducting Channel in a Phospholipid Bilayer Membrane

Dynamic Assessment of Bilayer Thickness by Varying Phospholipid and Hydraphile Synthetic Channel Chain Lengths

“…[6][7][8][9]12 These channels show open-shut behavior characteristic of protein channels. They exhibit selectivity for cations over anions and for Na + over K + .…”

Synthesis and chemical properties of polyacetylenic derivatives of benzo- and dibenzo- crown ethers

“…1 However, the chemistry of acetylenic derivatives of the crown ethers remains poorly studied owing to the limited synthetic approaches to these compounds. Only a few publications are devoted to the synthesis of acetylenylbenzocrown ethers by cross-coupling of iodoarenes with terminal acetylenes, 2,3 whereas the preparation of polyethynyl-benzo-crown ethers is not described at all. Moreover, we have found some important details, both when we tried to obtain even simple monoethynylbenzocrown ethers and when we carried out the Mannich reaction 4 with them.…”

“…The starting diiodobenzocrown ethers 1-3 were synthesized by direct oxidative iodination of the corresponding ethers in an I 2 -HIO 3 -H 2 SO 4 system 7 at 50-55 о C (yield 50-80%) (Scheme 1). Under the above conditions, for dibenzo-18-crown-6 (2 mol of iodination mixture / mol of starting compound) a mixture of cis- (2) and trans-(3) isomers was obtained in a total yield of 83%. Tetraiododibenzocrown ether 4 (60%) was obtained from dibenzo-18-crown-6 and I 2, NaIO 4 , and H 2 SO 4 in dioxane under reflux.…”

“…Tetraiododibenzocrown ether 4 (60%) was obtained from dibenzo-18-crown-6 and I 2, NaIO 4 , and H 2 SO 4 in dioxane under reflux. The synthesis of individual cis- (2) and trans-(3) isomers was realized from the corresponding dinitrodibenzo-18-crown ethers (2а, 3а) (Scheme 2). Nitration of dibenzo-18-crown ether by nitric acid mixed with acetic acid in chloroform resulted in a mixture of cis-and trans-dinitrodibenzo-18-crown ethers, which were separated by recrystallization from DMF.…”

“…11 The cis-iodocrown ether (2) and trans-isomer (3) were formed in 32% and 42% yields, respectively. We used trimethylsilylacetylene (5a), p-ethynylbenzaldehyde (5b) and 2-methylbut-3-yn-2-ol (5c) as acetylenic components in the cross-coupling 5,12 of polyiodocrown ethers (1)(2)(3)(4). A special interest in acetylenylbenzocrown ethers bearing formyl groups was caused by the possibility of their forming stable nitronyl-nitroxide radicals, since they are precursors of 2-imidazoline.…”