4A=@KJ BE-code -NFA?JA@ 4A=@KJ BE-code -NFA?JA@ 4A=@KJ BE-code -NFA?JA@ 4A=@KJ BE-code -NFA?JA@ 4A=@KJ BE-code -NFA?JA@ , *-*-*-! H=EA@5 Table ) that evolves the Cβ chemical shift explicitly. The observed S/N is, however, roughly a factor of 2-3 lower than expected, if no magnetization loss is happening during the BE pulse, considering the fact that the total transverse evolution time for the BE-CANH is shorter by 10 ms than that for caC-BcaNH, and T2' for GB1 Cα spin is ~10 ms. At the moment, the BE-pulses were "optimally controlled" using a single spin simulation involving only one isotropic chemical shift (SI), ignoring the influence of many other factors e.g., the dipolar and scaler couplings, the chemical shift anisotropy and the sample spinning, the RF interference from the other channels in addition to the spin relaxation. To see how much these factors affect the magnetization loss during the BE-block, we carried out SpinEvolution 20 simulations, and compared the results on a simple 2-spin system involving only the Cα and Cβ spins with a scalar coupling to those with an 8-spin system including 1 H, C, N spins with all the relevant dipolar and scalar couplings. The details of the simulations are described in SI. The result showed that in the 8-spin system, a factor of 1.7-2.5 loss of the magnetization was observed as compared with the 2-spin system (Figure ). Thus, the loss of S/N observed in experiment is most likely due to the suboptimal design of the BE pulse, which can be improved in exchange with the computational cost.