Synthesis and Anion Binding Affinities of Novel Molecular Tweezers Based on Chenodeoxycholic Acid Bearing Different Lengths of Arm

Molecular tweezers based on chenodeoxycholic acid bearing different lengths of arm were synthesized and their anion binding affinities were evaluated by 1 H NMR, isothermal calorimetric titration, and ESI mass spectrometry. Molecular tweezer 6 showed a high selectivity toward H 2 PO 4 - over Cl - , Br - , I - , and CH 3 CO 2 - by 1 H NMR titration, whereas the association constant for F - revealed the largest value as determined by ITC. The selectivity of 6 towards F - was about 10 3 times higher than that of Cl - , H 2 PO 4 - , and CH 3 CO 2 - . ITC experiment of 6 with F - in a DMSO showed two binding modes; two sequential association constants K 1 = 2.77 × 10 5 M -1 and K 2 = 8.68 x 10 6 M -1 were found. These sequential bindings were confirmed by ESI mass spectrometry. 1: 1 and 1: 2 complexes of 6 and F - were found at m/z 868.08 and 884.04.

[1]  K. Ahn,et al.  Artificial receptors that provides a preorganized hydrophobic environment: a biomimetic approach to dopamine recognition in water. , 2006, The Journal of organic chemistry.

[2]  Hong-Seok Kim,et al.  A hyodeoxycholic acid-based molecular tweezer: a highly selective fluoride anion receptor , 2005 .

[3]  Bradley D. Smith,et al.  Substrate discrimination by cholapod anion receptors: geometric effects and the "affinity-selectivity principle". , 2005, Journal of the American Chemical Society.

[4]  T. N. Guru Row,et al.  Selective and unusual fluoride ion complexation by a steroidal receptor using OH...F- and CH...F- interactions: a new motif for anion coordination? , 2005, Organic letters.

[5]  H. Nam,et al.  Ion-selective electrodes based on molecular tweezer-type neutral carriers. , 2004, Talanta.

[6]  K. Rissanen,et al.  An extraction-based assay for neutral anionophores: the measurement of high binding constants to steroidal receptors in a nonpolar solvent. , 2002, Chemistry.

[7]  Anthony P. Davis,et al.  New "cholapod" anionophores; high-affinity halide receptors derived from cholic acid. , 2001, Journal of the American Chemical Society.

[8]  Philip A. Gale,et al.  Anion Recognition and Sensing: The State of the Art and Future Perspectives. , 2001, Angewandte Chemie.

[9]  L. Fielding.  Determination of Association Constants (Ka) from Solution NMR Data , 2000 .

[10]  B. S. Choi,et al.  Synthesis and antimicrobial activity of squalamine analogue. , 2000, Bioorganic & medicinal chemistry.

[11]  François Diederich,et al.  Steroids in Molecular Recognition. , 1997, Chemical reviews.

[12]  J. Perry,et al.  ANION RECOGNITION BY TRIPODAL RECEPTORS DERIVED FROM CHOLIC ACID , 1997 .

[13]  J. Perry,et al.  A Steroid‐Based Cryptand for Halide Anions , 1996 .

[14]  M. Newcomb,et al.  Macrocycles Containing Tin. The Preparation of Macrobicyclic Lewis Acidic Hosts Containing Two Tin Atoms and 119-Sn NMR Studies of Their Chloride and Bromide Binding Properties in Solution , 1989 .