NMR signals overlapped with each other seriously in 1H and 13C NMR spectrum of plant cyclopeptides due to similarity of chemical shifts in different amino acid residuals. Unambiguous assignments are difficult without TOCSY pulse sequence. In general, one amino acid residual is one independent spin system in NMR term. Proton signals due to different amino acid residuals can be distinguished from each other easily in TOCSY spectrum because TOCSY can provide proton total correlation for every independent spin ...