Cyclotides, Cyclic Peptides Derived from Clitoria ternatea Linn Mature Pods, Hold Promise as Potential Antimicrobial Agent

Cyclotides, cysteine-rich peptides, are derived from various plant sources. Within the Fabaceae family, Clitoria ternatea Linn distinguishes itself as the only species that has been confirmed to contain cyclotides in its tissues. Several investigations have been undertaken to identify and evaluate the activity of cyclotides derived from the plant. However, the investigation of cyclotides derived from mature pods of C. ternatea remains unexplored. To fill this gap, this study utilized three different extraction methods and employed LC-MS analysis to evaluate their effectiveness in extracting cyclotides. A solution comprising 70 % ethanol and 30 % water exhibited the highest efficacy for cyclotide extraction. A total of 14 cyclotide-like molecules were successfully identified using this approach. Mixtures of cyclotides M1 and M2 demonstrated significant antibacterial efficacy against Bacillus subtilis (inhibition diameters: 17.83-19.67 mm) and Pseudomonas aeruginosa (inhibition diameters: 19.33-20.33 mm). The minimum inhibitory concentration (MIC) of semi-purified sample E70-F2 is 1.56 mg/mL, while the MIC of semi-purified E70-F3 is 0.78 mg/mL. The MS tandem technique was utilized to sequence a total of seven known cyclotides. The findings of this study demonstrate considerable potential for the application of cyclotides derived from mature pods of C. ternatea as an environmentally friendly antimicrobial agent.