- TROPANE COMPOUNDS
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A compound according to Formula I or II: (I) or (II) wherein R1, R1b, R2, L1, and L2 and L2b are as defined in the specification, pharmaceutical compositions thereof, and methods of use thereof.
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Page/Page column 404-405
(2009/05/30)
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- A Selective Receptor for Arginine Derivatives in Aqueous Media. Energetic Consequences of Salt Bridges That Are Highly Exposed to Water
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Quantitative measures of salt-bridge-type interactions in a highly exposed aqueous environment have been obtained by modifying the well-studied cyclophane platform 1 to include carboxylates in close proximity to bound, cationic guests, producing hosts 2 and 3. Many guests show significantly enhanced binding to 2 and 3, but cations of the RNMe3+ type show little or no enhancement. We propose that the latter observations result from the fact that RNMe3+ compounds have very diffuse positive charges. Guests that show enhanced binding have focused regions of large, positive electrostatic potential. The highly charged 3 is able to bind very polar, very well-solvated guests, including a series of arginine-based dipeptides. Neutral, water-soluble host 4 was prepared and found to show a decreased affinity for cationic guests. We propose a novel induced dipole mechanism to rationalize these results.
- Ngola, Sarah M.,Kearney, Patrick C.,Mecozzi, Sandro,Russell, Keith,Dougherty, Dennis A.
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p. 1192 - 1201
(2007/10/03)
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