پست سیزدهم- HCCH-TOCSY

نکته:

If this is written at the end of pulse sequence: SR(F1):1/4 SW H(F1)
means that:

should subtract or add this to the frequency to have the right SW
Why this happens?
Because of the jump in pulse sequence so

The experiments HCCH-TOCSY and HCCH-COSY are alternatives to the ¹³C-TOCSY-HSQC experiment which shows a markedly reduced sensitivity for larger proteins. In both experiments the magnetization is transferred via direct ¹J couplings between the atoms, allowing a much faster magnetization transfer as in the TOCSY-HSQC. Magnetization is transferred (blue arrows) from a sidechain (or backbone) proton (red) to the direct attached carbon atom (yellow), by ¹J coupling to the neighboring carbon atoms (yellow) and finally to their attached protons (red). Therefore, a HCCH-TOCSY experiment looks in principle the same like a ¹³C-TOCSY-HSQC. The type of an amino acid can be recognized from the peak pattern in the usual way, as can be seen from the picture below. It shows some regions from different planes of a HCCH-TOCSY which together contain the complete spin system of a leucine residue: