Table 3. Binding Constant, Free Energy, Enthalpy, and Entropy of Binding Derived from ITC Measurements for M2TM_Udorn/72.

liganda	Kdb	ΔGc,d	ΔHc,e	–TΔSc,f
1	2.17 ± 0.52	–7.77 ± 0.14	–6.66 ± 0.50	–1.11 ± 0.52
2	0.51 ± 0.26	–8.64 ± 0.30	–7.60 ± 0.28	–1.04 ± 0.41
2-Rg	0.32 ± 0.16	–8.97 ± 0.26	–7.54 ± 0.34	–1.42 ± 0.43
2-Sg	0.34 ± 0.12	–8.88 ± 0.21	–7.73 ± 0.28	–1.15 ± 0.35
3	0.13 ± 0.12	–9.30 ± 0.43	–4.19 ± 0.28	–5.12 ± 0.51

^aSee Scheme 1.

^bBinding constant K_d in μM calculated from measured K_a in M^–1 by K_d = 1/K_a × 10^–6 and error in K_d in μM determined by K_d, error = (K_a, error/K_a²) × 10^–6 (ITC measurements were performed in triplicate for each ligand to calculate means and standard deviations).

^cIn kcal mol^–1.

^dFree energy of binding computed from K_d by ΔG = −RT ln(K_d^ref/K_d) with K_d^ref = 1 M and T = 300 K and error in ΔG determined according to with T = 300 K.

^eEnthalpy of binding and error in the enthalpy of binding calculated from measured binding enthalpy and measured error by ΔH = ΔH_measured (T/T_measured) with T = 300 K and the temperature at which the ITC measurements were performed T_measured = 293.15 K.

^fEntropy of binding calculated by ΔS = (−ΔG + ΔH)/T and error in ΔS computed by the equation .

^gThe purity of each enantiomer used was 90% for 2-R and 95% for 2-S; the enantiomeric excess (ee) of both 2-R and 2-S is 99% (Mosher’s method); the purity of compound 3 used was >99%.