Application of a TLC chemical method to detection of cyclotides in plants

Iodine, Dragendorff's reagent, ninhydrin and Coomassie brilliant blue G-250 reagents were used to detect cyclotides from proteins, cyclopeptides, linear-peptides and amino acids in the thin layer chromatography (TLC). Cyclotides could be distinguished from the others by comparing the TLC col-oring plots with G-250 and ninhydrin reagents. With this method, cyclotides were discovered in Viola labridorica, V. tricolor, V. hamiltoniana, Momordica charantia, and M. cochinchinensis and over 10 cyclotides were isolated, three of which were determined as known cyclotides cycloviolacin O2, kalata B1 and vary peptide A.