Table 2.
Change in chemical shifts (Δδ) observed for BuNme3+ when bound to A2N, A2Gly-N, and Gly-A2N. The analogous Δδ values previously observed for the peptide guest Ac-Kme3G-NH2 when bound to A2N are included for reference.18
| Receptor: | A2Na | A2Nb | A2Gly-Nb | Gly-A2Nb,c | |
|---|---|---|---|---|---|
| Guest: | Ac-Kme3G-NH2 | BuNme3+ | BuNme3+ | BuNme3+ | |
| Δδ (ppm): | Nme3 | -2.46 | -2.41 | -2.32 | -1.99 |
| δ | -3.45 | - | - | - | |
| γ | -3.25 | -2.93 | -2.80 | -2.54 | |
| β | -2.09 | -1.40 | -1.34 | -1.31 | |
| α | -0.60 | -0.47 | -0.46 | -0.49 | |
a
Conditions: 10 mM borate buffered D2O (pH 8.67).
b
Conditions: 10 mM borate buffered D2O (pH 8.5)
c
Used as a mixture of isomers containing predominantly meso2-Gly-A2N.